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author | Alex Elder <aelder@sgi.com> | 2010-05-24 16:57:36 (GMT) |
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committer | Alex Elder <aelder@sgi.com> | 2010-05-24 16:57:36 (GMT) |
commit | 88e88374ee4958786397a57f684de6f1fc5e0242 (patch) | |
tree | 750fe86ece5d65e597223eb07c5ce7cf5b3749a0 | |
parent | 7e125f7b9cbfce4101191b8076d606c517a73066 (diff) | |
parent | ccf7c23fc129e75ef60e6f59f60a485b7a056598 (diff) | |
download | linux-fsl-qoriq-88e88374ee4958786397a57f684de6f1fc5e0242.tar.xz |
Merge branch 'delayed-logging-for-2.6.35' into for-linus
-rw-r--r-- | Documentation/filesystems/xfs-delayed-logging-design.txt | 816 | ||||
-rw-r--r-- | fs/xfs/Makefile | 1 | ||||
-rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 9 | ||||
-rw-r--r-- | fs/xfs/linux-2.6/xfs_quotaops.c | 1 | ||||
-rw-r--r-- | fs/xfs/linux-2.6/xfs_super.c | 12 | ||||
-rw-r--r-- | fs/xfs/linux-2.6/xfs_trace.h | 83 | ||||
-rw-r--r-- | fs/xfs/quota/xfs_dquot.c | 6 | ||||
-rw-r--r-- | fs/xfs/xfs_ag.h | 24 | ||||
-rw-r--r-- | fs/xfs/xfs_alloc.c | 357 | ||||
-rw-r--r-- | fs/xfs/xfs_alloc.h | 7 | ||||
-rw-r--r-- | fs/xfs/xfs_alloc_btree.c | 2 | ||||
-rw-r--r-- | fs/xfs/xfs_buf_item.c | 166 | ||||
-rw-r--r-- | fs/xfs/xfs_buf_item.h | 18 | ||||
-rw-r--r-- | fs/xfs/xfs_error.c | 2 | ||||
-rw-r--r-- | fs/xfs/xfs_log.c | 120 | ||||
-rw-r--r-- | fs/xfs/xfs_log.h | 14 | ||||
-rw-r--r-- | fs/xfs/xfs_log_cil.c | 725 | ||||
-rw-r--r-- | fs/xfs/xfs_log_priv.h | 118 | ||||
-rw-r--r-- | fs/xfs/xfs_log_recover.c | 46 | ||||
-rw-r--r-- | fs/xfs/xfs_log_recover.h | 2 | ||||
-rw-r--r-- | fs/xfs/xfs_mount.h | 1 | ||||
-rw-r--r-- | fs/xfs/xfs_trans.c | 144 | ||||
-rw-r--r-- | fs/xfs/xfs_trans.h | 44 | ||||
-rw-r--r-- | fs/xfs/xfs_trans_buf.c | 46 | ||||
-rw-r--r-- | fs/xfs/xfs_trans_item.c | 114 | ||||
-rw-r--r-- | fs/xfs/xfs_trans_priv.h | 15 | ||||
-rw-r--r-- | fs/xfs/xfs_types.h | 2 |
27 files changed, 2382 insertions, 513 deletions
diff --git a/Documentation/filesystems/xfs-delayed-logging-design.txt b/Documentation/filesystems/xfs-delayed-logging-design.txt new file mode 100644 index 0000000..d8119e9 --- /dev/null +++ b/Documentation/filesystems/xfs-delayed-logging-design.txt @@ -0,0 +1,816 @@ +XFS Delayed Logging Design +-------------------------- + +Introduction to Re-logging in XFS +--------------------------------- + +XFS logging is a combination of logical and physical logging. Some objects, +such as inodes and dquots, are logged in logical format where the details +logged are made up of the changes to in-core structures rather than on-disk +structures. Other objects - typically buffers - have their physical changes +logged. The reason for these differences is to reduce the amount of log space +required for objects that are frequently logged. Some parts of inodes are more +frequently logged than others, and inodes are typically more frequently logged +than any other object (except maybe the superblock buffer) so keeping the +amount of metadata logged low is of prime importance. + +The reason that this is such a concern is that XFS allows multiple separate +modifications to a single object to be carried in the log at any given time. +This allows the log to avoid needing to flush each change to disk before +recording a new change to the object. XFS does this via a method called +"re-logging". Conceptually, this is quite simple - all it requires is that any +new change to the object is recorded with a *new copy* of all the existing +changes in the new transaction that is written to the log. + +That is, if we have a sequence of changes A through to F, and the object was +written to disk after change D, we would see in the log the following series +of transactions, their contents and the log sequence number (LSN) of the +transaction: + + Transaction Contents LSN + A A X + B A+B X+n + C A+B+C X+n+m + D A+B+C+D X+n+m+o + <object written to disk> + E E Y (> X+n+m+o) + F E+F Yٍ+p + +In other words, each time an object is relogged, the new transaction contains +the aggregation of all the previous changes currently held only in the log. + +This relogging technique also allows objects to be moved forward in the log so +that an object being relogged does not prevent the tail of the log from ever +moving forward. This can be seen in the table above by the changing +(increasing) LSN of each subsquent transaction - the LSN is effectively a +direct encoding of the location in the log of the transaction. + +This relogging is also used to implement long-running, multiple-commit +transactions. These transaction are known as rolling transactions, and require +a special log reservation known as a permanent transaction reservation. A +typical example of a rolling transaction is the removal of extents from an +inode which can only be done at a rate of two extents per transaction because +of reservation size limitations. Hence a rolling extent removal transaction +keeps relogging the inode and btree buffers as they get modified in each +removal operation. This keeps them moving forward in the log as the operation +progresses, ensuring that current operation never gets blocked by itself if the +log wraps around. + +Hence it can be seen that the relogging operation is fundamental to the correct +working of the XFS journalling subsystem. From the above description, most +people should be able to see why the XFS metadata operations writes so much to +the log - repeated operations to the same objects write the same changes to +the log over and over again. Worse is the fact that objects tend to get +dirtier as they get relogged, so each subsequent transaction is writing more +metadata into the log. + +Another feature of the XFS transaction subsystem is that most transactions are +asynchronous. That is, they don't commit to disk until either a log buffer is +filled (a log buffer can hold multiple transactions) or a synchronous operation +forces the log buffers holding the transactions to disk. This means that XFS is +doing aggregation of transactions in memory - batching them, if you like - to +minimise the impact of the log IO on transaction throughput. + +The limitation on asynchronous transaction throughput is the number and size of +log buffers made available by the log manager. By default there are 8 log +buffers available and the size of each is 32kB - the size can be increased up +to 256kB by use of a mount option. + +Effectively, this gives us the maximum bound of outstanding metadata changes +that can be made to the filesystem at any point in time - if all the log +buffers are full and under IO, then no more transactions can be committed until +the current batch completes. It is now common for a single current CPU core to +be to able to issue enough transactions to keep the log buffers full and under +IO permanently. Hence the XFS journalling subsystem can be considered to be IO +bound. + +Delayed Logging: Concepts +------------------------- + +The key thing to note about the asynchronous logging combined with the +relogging technique XFS uses is that we can be relogging changed objects +multiple times before they are committed to disk in the log buffers. If we +return to the previous relogging example, it is entirely possible that +transactions A through D are committed to disk in the same log buffer. + +That is, a single log buffer may contain multiple copies of the same object, +but only one of those copies needs to be there - the last one "D", as it +contains all the changes from the previous changes. In other words, we have one +necessary copy in the log buffer, and three stale copies that are simply +wasting space. When we are doing repeated operations on the same set of +objects, these "stale objects" can be over 90% of the space used in the log +buffers. It is clear that reducing the number of stale objects written to the +log would greatly reduce the amount of metadata we write to the log, and this +is the fundamental goal of delayed logging. + +From a conceptual point of view, XFS is already doing relogging in memory (where +memory == log buffer), only it is doing it extremely inefficiently. It is using +logical to physical formatting to do the relogging because there is no +infrastructure to keep track of logical changes in memory prior to physically +formatting the changes in a transaction to the log buffer. Hence we cannot avoid +accumulating stale objects in the log buffers. + +Delayed logging is the name we've given to keeping and tracking transactional +changes to objects in memory outside the log buffer infrastructure. Because of +the relogging concept fundamental to the XFS journalling subsystem, this is +actually relatively easy to do - all the changes to logged items are already +tracked in the current infrastructure. The big problem is how to accumulate +them and get them to the log in a consistent, recoverable manner. +Describing the problems and how they have been solved is the focus of this +document. + +One of the key changes that delayed logging makes to the operation of the +journalling subsystem is that it disassociates the amount of outstanding +metadata changes from the size and number of log buffers available. In other +words, instead of there only being a maximum of 2MB of transaction changes not +written to the log at any point in time, there may be a much greater amount +being accumulated in memory. Hence the potential for loss of metadata on a +crash is much greater than for the existing logging mechanism. + +It should be noted that this does not change the guarantee that log recovery +will result in a consistent filesystem. What it does mean is that as far as the +recovered filesystem is concerned, there may be many thousands of transactions +that simply did not occur as a result of the crash. This makes it even more +important that applications that care about their data use fsync() where they +need to ensure application level data integrity is maintained. + +It should be noted that delayed logging is not an innovative new concept that +warrants rigorous proofs to determine whether it is correct or not. The method +of accumulating changes in memory for some period before writing them to the +log is used effectively in many filesystems including ext3 and ext4. Hence +no time is spent in this document trying to convince the reader that the +concept is sound. Instead it is simply considered a "solved problem" and as +such implementing it in XFS is purely an exercise in software engineering. + +The fundamental requirements for delayed logging in XFS are simple: + + 1. Reduce the amount of metadata written to the log by at least + an order of magnitude. + 2. Supply sufficient statistics to validate Requirement #1. + 3. Supply sufficient new tracing infrastructure to be able to debug + problems with the new code. + 4. No on-disk format change (metadata or log format). + 5. Enable and disable with a mount option. + 6. No performance regressions for synchronous transaction workloads. + +Delayed Logging: Design +----------------------- + +Storing Changes + +The problem with accumulating changes at a logical level (i.e. just using the +existing log item dirty region tracking) is that when it comes to writing the +changes to the log buffers, we need to ensure that the object we are formatting +is not changing while we do this. This requires locking the object to prevent +concurrent modification. Hence flushing the logical changes to the log would +require us to lock every object, format them, and then unlock them again. + +This introduces lots of scope for deadlocks with transactions that are already +running. For example, a transaction has object A locked and modified, but needs +the delayed logging tracking lock to commit the transaction. However, the +flushing thread has the delayed logging tracking lock already held, and is +trying to get the lock on object A to flush it to the log buffer. This appears +to be an unsolvable deadlock condition, and it was solving this problem that +was the barrier to implementing delayed logging for so long. + +The solution is relatively simple - it just took a long time to recognise it. +Put simply, the current logging code formats the changes to each item into an +vector array that points to the changed regions in the item. The log write code +simply copies the memory these vectors point to into the log buffer during +transaction commit while the item is locked in the transaction. Instead of +using the log buffer as the destination of the formatting code, we can use an +allocated memory buffer big enough to fit the formatted vector. + +If we then copy the vector into the memory buffer and rewrite the vector to +point to the memory buffer rather than the object itself, we now have a copy of +the changes in a format that is compatible with the log buffer writing code. +that does not require us to lock the item to access. This formatting and +rewriting can all be done while the object is locked during transaction commit, +resulting in a vector that is transactionally consistent and can be accessed +without needing to lock the owning item. + +Hence we avoid the need to lock items when we need to flush outstanding +asynchronous transactions to the log. The differences between the existing +formatting method and the delayed logging formatting can be seen in the +diagram below. + +Current format log vector: + +Object +---------------------------------------------+ +Vector 1 +----+ +Vector 2 +----+ +Vector 3 +----------+ + +After formatting: + +Log Buffer +-V1-+-V2-+----V3----+ + +Delayed logging vector: + +Object +---------------------------------------------+ +Vector 1 +----+ +Vector 2 +----+ +Vector 3 +----------+ + +After formatting: + +Memory Buffer +-V1-+-V2-+----V3----+ +Vector 1 +----+ +Vector 2 +----+ +Vector 3 +----------+ + +The memory buffer and associated vector need to be passed as a single object, +but still need to be associated with the parent object so if the object is +relogged we can replace the current memory buffer with a new memory buffer that +contains the latest changes. + +The reason for keeping the vector around after we've formatted the memory +buffer is to support splitting vectors across log buffer boundaries correctly. +If we don't keep the vector around, we do not know where the region boundaries +are in the item, so we'd need a new encapsulation method for regions in the log +buffer writing (i.e. double encapsulation). This would be an on-disk format +change and as such is not desirable. It also means we'd have to write the log +region headers in the formatting stage, which is problematic as there is per +region state that needs to be placed into the headers during the log write. + +Hence we need to keep the vector, but by attaching the memory buffer to it and +rewriting the vector addresses to point at the memory buffer we end up with a +self-describing object that can be passed to the log buffer write code to be +handled in exactly the same manner as the existing log vectors are handled. +Hence we avoid needing a new on-disk format to handle items that have been +relogged in memory. + + +Tracking Changes + +Now that we can record transactional changes in memory in a form that allows +them to be used without limitations, we need to be able to track and accumulate +them so that they can be written to the log at some later point in time. The +log item is the natural place to store this vector and buffer, and also makes sense +to be the object that is used to track committed objects as it will always +exist once the object has been included in a transaction. + +The log item is already used to track the log items that have been written to +the log but not yet written to disk. Such log items are considered "active" +and as such are stored in the Active Item List (AIL) which is a LSN-ordered +double linked list. Items are inserted into this list during log buffer IO +completion, after which they are unpinned and can be written to disk. An object +that is in the AIL can be relogged, which causes the object to be pinned again +and then moved forward in the AIL when the log buffer IO completes for that +transaction. + +Essentially, this shows that an item that is in the AIL can still be modified +and relogged, so any tracking must be separate to the AIL infrastructure. As +such, we cannot reuse the AIL list pointers for tracking committed items, nor +can we store state in any field that is protected by the AIL lock. Hence the +committed item tracking needs it's own locks, lists and state fields in the log +item. + +Similar to the AIL, tracking of committed items is done through a new list +called the Committed Item List (CIL). The list tracks log items that have been +committed and have formatted memory buffers attached to them. It tracks objects +in transaction commit order, so when an object is relogged it is removed from +it's place in the list and re-inserted at the tail. This is entirely arbitrary +and done to make it easy for debugging - the last items in the list are the +ones that are most recently modified. Ordering of the CIL is not necessary for +transactional integrity (as discussed in the next section) so the ordering is +done for convenience/sanity of the developers. + + +Delayed Logging: Checkpoints + +When we have a log synchronisation event, commonly known as a "log force", +all the items in the CIL must be written into the log via the log buffers. +We need to write these items in the order that they exist in the CIL, and they +need to be written as an atomic transaction. The need for all the objects to be +written as an atomic transaction comes from the requirements of relogging and +log replay - all the changes in all the objects in a given transaction must +either be completely replayed during log recovery, or not replayed at all. If +a transaction is not replayed because it is not complete in the log, then +no later transactions should be replayed, either. + +To fulfill this requirement, we need to write the entire CIL in a single log +transaction. Fortunately, the XFS log code has no fixed limit on the size of a +transaction, nor does the log replay code. The only fundamental limit is that +the transaction cannot be larger than just under half the size of the log. The +reason for this limit is that to find the head and tail of the log, there must +be at least one complete transaction in the log at any given time. If a +transaction is larger than half the log, then there is the possibility that a +crash during the write of a such a transaction could partially overwrite the +only complete previous transaction in the log. This will result in a recovery +failure and an inconsistent filesystem and hence we must enforce the maximum +size of a checkpoint to be slightly less than a half the log. + +Apart from this size requirement, a checkpoint transaction looks no different +to any other transaction - it contains a transaction header, a series of +formatted log items and a commit record at the tail. From a recovery +perspective, the checkpoint transaction is also no different - just a lot +bigger with a lot more items in it. The worst case effect of this is that we +might need to tune the recovery transaction object hash size. + +Because the checkpoint is just another transaction and all the changes to log +items are stored as log vectors, we can use the existing log buffer writing +code to write the changes into the log. To do this efficiently, we need to +minimise the time we hold the CIL locked while writing the checkpoint +transaction. The current log write code enables us to do this easily with the +way it separates the writing of the transaction contents (the log vectors) from +the transaction commit record, but tracking this requires us to have a +per-checkpoint context that travels through the log write process through to +checkpoint completion. + +Hence a checkpoint has a context that tracks the state of the current +checkpoint from initiation to checkpoint completion. A new context is initiated +at the same time a checkpoint transaction is started. That is, when we remove +all the current items from the CIL during a checkpoint operation, we move all +those changes into the current checkpoint context. We then initialise a new +context and attach that to the CIL for aggregation of new transactions. + +This allows us to unlock the CIL immediately after transfer of all the +committed items and effectively allow new transactions to be issued while we +are formatting the checkpoint into the log. It also allows concurrent +checkpoints to be written into the log buffers in the case of log force heavy +workloads, just like the existing transaction commit code does. This, however, +requires that we strictly order the commit records in the log so that +checkpoint sequence order is maintained during log replay. + +To ensure that we can be writing an item into a checkpoint transaction at +the same time another transaction modifies the item and inserts the log item +into the new CIL, then checkpoint transaction commit code cannot use log items +to store the list of log vectors that need to be written into the transaction. +Hence log vectors need to be able to be chained together to allow them to be +detatched from the log items. That is, when the CIL is flushed the memory +buffer and log vector attached to each log item needs to be attached to the +checkpoint context so that the log item can be released. In diagrammatic form, +the CIL would look like this before the flush: + + CIL Head + | + V + Log Item <-> log vector 1 -> memory buffer + | -> vector array + V + Log Item <-> log vector 2 -> memory buffer + | -> vector array + V + ...... + | + V + Log Item <-> log vector N-1 -> memory buffer + | -> vector array + V + Log Item <-> log vector N -> memory buffer + -> vector array + +And after the flush the CIL head is empty, and the checkpoint context log +vector list would look like: + + Checkpoint Context + | + V + log vector 1 -> memory buffer + | -> vector array + | -> Log Item + V + log vector 2 -> memory buffer + | -> vector array + | -> Log Item + V + ...... + | + V + log vector N-1 -> memory buffer + | -> vector array + | -> Log Item + V + log vector N -> memory buffer + -> vector array + -> Log Item + +Once this transfer is done, the CIL can be unlocked and new transactions can +start, while the checkpoint flush code works over the log vector chain to +commit the checkpoint. + +Once the checkpoint is written into the log buffers, the checkpoint context is +attached to the log buffer that the commit record was written to along with a +completion callback. Log IO completion will call that callback, which can then +run transaction committed processing for the log items (i.e. insert into AIL +and unpin) in the log vector chain and then free the log vector chain and +checkpoint context. + +Discussion Point: I am uncertain as to whether the log item is the most +efficient way to track vectors, even though it seems like the natural way to do +it. The fact that we walk the log items (in the CIL) just to chain the log +vectors and break the link between the log item and the log vector means that +we take a cache line hit for the log item list modification, then another for +the log vector chaining. If we track by the log vectors, then we only need to +break the link between the log item and the log vector, which means we should +dirty only the log item cachelines. Normally I wouldn't be concerned about one +vs two dirty cachelines except for the fact I've seen upwards of 80,000 log +vectors in one checkpoint transaction. I'd guess this is a "measure and +compare" situation that can be done after a working and reviewed implementation +is in the dev tree.... + +Delayed Logging: Checkpoint Sequencing + +One of the key aspects of the XFS transaction subsystem is that it tags +committed transactions with the log sequence number of the transaction commit. +This allows transactions to be issued asynchronously even though there may be +future operations that cannot be completed until that transaction is fully +committed to the log. In the rare case that a dependent operation occurs (e.g. +re-using a freed metadata extent for a data extent), a special, optimised log +force can be issued to force the dependent transaction to disk immediately. + +To do this, transactions need to record the LSN of the commit record of the +transaction. This LSN comes directly from the log buffer the transaction is +written into. While this works just fine for the existing transaction +mechanism, it does not work for delayed logging because transactions are not +written directly into the log buffers. Hence some other method of sequencing +transactions is required. + +As discussed in the checkpoint section, delayed logging uses per-checkpoint +contexts, and as such it is simple to assign a sequence number to each +checkpoint. Because the switching of checkpoint contexts must be done +atomically, it is simple to ensure that each new context has a monotonically +increasing sequence number assigned to it without the need for an external +atomic counter - we can just take the current context sequence number and add +one to it for the new context. + +Then, instead of assigning a log buffer LSN to the transaction commit LSN +during the commit, we can assign the current checkpoint sequence. This allows +operations that track transactions that have not yet completed know what +checkpoint sequence needs to be committed before they can continue. As a +result, the code that forces the log to a specific LSN now needs to ensure that +the log forces to a specific checkpoint. + +To ensure that we can do this, we need to track all the checkpoint contexts +that are currently committing to the log. When we flush a checkpoint, the +context gets added to a "committing" list which can be searched. When a +checkpoint commit completes, it is removed from the committing list. Because +the checkpoint context records the LSN of the commit record for the checkpoint, +we can also wait on the log buffer that contains the commit record, thereby +using the existing log force mechanisms to execute synchronous forces. + +It should be noted that the synchronous forces may need to be extended with +mitigation algorithms similar to the current log buffer code to allow +aggregation of multiple synchronous transactions if there are already +synchronous transactions being flushed. Investigation of the performance of the +current design is needed before making any decisions here. + +The main concern with log forces is to ensure that all the previous checkpoints +are also committed to disk before the one we need to wait for. Therefore we +need to check that all the prior contexts in the committing list are also +complete before waiting on the one we need to complete. We do this +synchronisation in the log force code so that we don't need to wait anywhere +else for such serialisation - it only matters when we do a log force. + +The only remaining complexity is that a log force now also has to handle the +case where the forcing sequence number is the same as the current context. That +is, we need to flush the CIL and potentially wait for it to complete. This is a +simple addition to the existing log forcing code to check the sequence numbers +and push if required. Indeed, placing the current sequence checkpoint flush in +the log force code enables the current mechanism for issuing synchronous +transactions to remain untouched (i.e. commit an asynchronous transaction, then +force the log at the LSN of that transaction) and so the higher level code +behaves the same regardless of whether delayed logging is being used or not. + +Delayed Logging: Checkpoint Log Space Accounting + +The big issue for a checkpoint transaction is the log space reservation for the +transaction. We don't know how big a checkpoint transaction is going to be +ahead of time, nor how many log buffers it will take to write out, nor the +number of split log vector regions are going to be used. We can track the +amount of log space required as we add items to the commit item list, but we +still need to reserve the space in the log for the checkpoint. + +A typical transaction reserves enough space in the log for the worst case space +usage of the transaction. The reservation accounts for log record headers, +transaction and region headers, headers for split regions, buffer tail padding, +etc. as well as the actual space for all the changed metadata in the +transaction. While some of this is fixed overhead, much of it is dependent on +the size of the transaction and the number of regions being logged (the number +of log vectors in the transaction). + +An example of the differences would be logging directory changes versus logging +inode changes. If you modify lots of inode cores (e.g. chmod -R g+w *), then +there are lots of transactions that only contain an inode core and an inode log +format structure. That is, two vectors totaling roughly 150 bytes. If we modify +10,000 inodes, we have about 1.5MB of metadata to write in 20,000 vectors. Each +vector is 12 bytes, so the total to be logged is approximately 1.75MB. In +comparison, if we are logging full directory buffers, they are typically 4KB +each, so we in 1.5MB of directory buffers we'd have roughly 400 buffers and a +buffer format structure for each buffer - roughly 800 vectors or 1.51MB total +space. From this, it should be obvious that a static log space reservation is +not particularly flexible and is difficult to select the "optimal value" for +all workloads. + +Further, if we are going to use a static reservation, which bit of the entire +reservation does it cover? We account for space used by the transaction +reservation by tracking the space currently used by the object in the CIL and +then calculating the increase or decrease in space used as the object is +relogged. This allows for a checkpoint reservation to only have to account for +log buffer metadata used such as log header records. + +However, even using a static reservation for just the log metadata is +problematic. Typically log record headers use at least 16KB of log space per +1MB of log space consumed (512 bytes per 32k) and the reservation needs to be +large enough to handle arbitrary sized checkpoint transactions. This +reservation needs to be made before the checkpoint is started, and we need to +be able to reserve the space without sleeping. For a 8MB checkpoint, we need a +reservation of around 150KB, which is a non-trivial amount of space. + +A static reservation needs to manipulate the log grant counters - we can take a +permanent reservation on the space, but we still need to make sure we refresh +the write reservation (the actual space available to the transaction) after +every checkpoint transaction completion. Unfortunately, if this space is not +available when required, then the regrant code will sleep waiting for it. + +The problem with this is that it can lead to deadlocks as we may need to commit +checkpoints to be able to free up log space (refer back to the description of +rolling transactions for an example of this). Hence we *must* always have +space available in the log if we are to use static reservations, and that is +very difficult and complex to arrange. It is possible to do, but there is a +simpler way. + +The simpler way of doing this is tracking the entire log space used by the +items in the CIL and using this to dynamically calculate the amount of log +space required by the log metadata. If this log metadata space changes as a +result of a transaction commit inserting a new memory buffer into the CIL, then +the difference in space required is removed from the transaction that causes +the change. Transactions at this level will *always* have enough space +available in their reservation for this as they have already reserved the +maximal amount of log metadata space they require, and such a delta reservation +will always be less than or equal to the maximal amount in the reservation. + +Hence we can grow the checkpoint transaction reservation dynamically as items +are added to the CIL and avoid the need for reserving and regranting log space +up front. This avoids deadlocks and removes a blocking point from the +checkpoint flush code. + +As mentioned early, transactions can't grow to more than half the size of the +log. Hence as part of the reservation growing, we need to also check the size +of the reservation against the maximum allowed transaction size. If we reach +the maximum threshold, we need to push the CIL to the log. This is effectively +a "background flush" and is done on demand. This is identical to +a CIL push triggered by a log force, only that there is no waiting for the +checkpoint commit to complete. This background push is checked and executed by +transaction commit code. + +If the transaction subsystem goes idle while we still have items in the CIL, +they will be flushed by the periodic log force issued by the xfssyncd. This log +force will push the CIL to disk, and if the transaction subsystem stays idle, +allow the idle log to be covered (effectively marked clean) in exactly the same +manner that is done for the existing logging method. A discussion point is +whether this log force needs to be done more frequently than the current rate +which is once every 30s. + + +Delayed Logging: Log Item Pinning + +Currently log items are pinned during transaction commit while the items are +still locked. This happens just after the items are formatted, though it could +be done any time before the items are unlocked. The result of this mechanism is +that items get pinned once for every transaction that is committed to the log +buffers. Hence items that are relogged in the log buffers will have a pin count +for every outstanding transaction they were dirtied in. When each of these +transactions is completed, they will unpin the item once. As a result, the item +only becomes unpinned when all the transactions complete and there are no +pending transactions. Thus the pinning and unpinning of a log item is symmetric +as there is a 1:1 relationship with transaction commit and log item completion. + +For delayed logging, however, we have an assymetric transaction commit to +completion relationship. Every time an object is relogged in the CIL it goes +through the commit process without a corresponding completion being registered. +That is, we now have a many-to-one relationship between transaction commit and +log item completion. The result of this is that pinning and unpinning of the +log items becomes unbalanced if we retain the "pin on transaction commit, unpin +on transaction completion" model. + +To keep pin/unpin symmetry, the algorithm needs to change to a "pin on +insertion into the CIL, unpin on checkpoint completion". In other words, the +pinning and unpinning becomes symmetric around a checkpoint context. We have to +pin the object the first time it is inserted into the CIL - if it is already in +the CIL during a transaction commit, then we do not pin it again. Because there +can be multiple outstanding checkpoint contexts, we can still see elevated pin +counts, but as each checkpoint completes the pin count will retain the correct +value according to it's context. + +Just to make matters more slightly more complex, this checkpoint level context +for the pin count means that the pinning of an item must take place under the +CIL commit/flush lock. If we pin the object outside this lock, we cannot +guarantee which context the pin count is associated with. This is because of +the fact pinning the item is dependent on whether the item is present in the +current CIL or not. If we don't pin the CIL first before we check and pin the +object, we have a race with CIL being flushed between the check and the pin +(or not pinning, as the case may be). Hence we must hold the CIL flush/commit +lock to guarantee that we pin the items correctly. + +Delayed Logging: Concurrent Scalability + +A fundamental requirement for the CIL is that accesses through transaction +commits must scale to many concurrent commits. The current transaction commit +code does not break down even when there are transactions coming from 2048 +processors at once. The current transaction code does not go any faster than if +there was only one CPU using it, but it does not slow down either. + +As a result, the delayed logging transaction commit code needs to be designed +for concurrency from the ground up. It is obvious that there are serialisation +points in the design - the three important ones are: + + 1. Locking out new transaction commits while flushing the CIL + 2. Adding items to the CIL and updating item space accounting + 3. Checkpoint commit ordering + +Looking at the transaction commit and CIL flushing interactions, it is clear +that we have a many-to-one interaction here. That is, the only restriction on +the number of concurrent transactions that can be trying to commit at once is +the amount of space available in the log for their reservations. The practical +limit here is in the order of several hundred concurrent transactions for a +128MB log, which means that it is generally one per CPU in a machine. + +The amount of time a transaction commit needs to hold out a flush is a +relatively long period of time - the pinning of log items needs to be done +while we are holding out a CIL flush, so at the moment that means it is held +across the formatting of the objects into memory buffers (i.e. while memcpy()s +are in progress). Ultimately a two pass algorithm where the formatting is done +separately to the pinning of objects could be used to reduce the hold time of +the transaction commit side. + +Because of the number of potential transaction commit side holders, the lock +really needs to be a sleeping lock - if the CIL flush takes the lock, we do not +want every other CPU in the machine spinning on the CIL lock. Given that +flushing the CIL could involve walking a list of tens of thousands of log +items, it will get held for a significant time and so spin contention is a +significant concern. Preventing lots of CPUs spinning doing nothing is the +main reason for choosing a sleeping lock even though nothing in either the +transaction commit or CIL flush side sleeps with the lock held. + +It should also be noted that CIL flushing is also a relatively rare operation +compared to transaction commit for asynchronous transaction workloads - only +time will tell if using a read-write semaphore for exclusion will limit +transaction commit concurrency due to cache line bouncing of the lock on the +read side. + +The second serialisation point is on the transaction commit side where items +are inserted into the CIL. Because transactions can enter this code +concurrently, the CIL needs to be protected separately from the above +commit/flush exclusion. It also needs to be an exclusive lock but it is only +held for a very short time and so a spin lock is appropriate here. It is +possible that this lock will become a contention point, but given the short +hold time once per transaction I think that contention is unlikely. + +The final serialisation point is the checkpoint commit record ordering code +that is run as part of the checkpoint commit and log force sequencing. The code +path that triggers a CIL flush (i.e. whatever triggers the log force) will enter +an ordering loop after writing all the log vectors into the log buffers but +before writing the commit record. This loop walks the list of committing +checkpoints and needs to block waiting for checkpoints to complete their commit +record write. As a result it needs a lock and a wait variable. Log force +sequencing also requires the same lock, list walk, and blocking mechanism to +ensure completion of checkpoints. + +These two sequencing operations can use the mechanism even though the +events they are waiting for are different. The checkpoint commit record +sequencing needs to wait until checkpoint contexts contain a commit LSN +(obtained through completion of a commit record write) while log force +sequencing needs to wait until previous checkpoint contexts are removed from +the committing list (i.e. they've completed). A simple wait variable and +broadcast wakeups (thundering herds) has been used to implement these two +serialisation queues. They use the same lock as the CIL, too. If we see too +much contention on the CIL lock, or too many context switches as a result of +the broadcast wakeups these operations can be put under a new spinlock and +given separate wait lists to reduce lock contention and the number of processes +woken by the wrong event. + + +Lifecycle Changes + +The existing log item life cycle is as follows: + + 1. Transaction allocate + 2. Transaction reserve + 3. Lock item + 4. Join item to transaction + If not already attached, + Allocate log item + Attach log item to owner item + Attach log item to transaction + 5. Modify item + Record modifications in log item + 6. Transaction commit + Pin item in memory + Format item into log buffer + Write commit LSN into transaction + Unlock item + Attach transaction to log buffer + + <log buffer IO dispatched> + <log buffer IO completes> + + 7. Transaction completion + Mark log item committed + Insert log item into AIL + Write commit LSN into log item + Unpin log item + 8. AIL traversal + Lock item + Mark log item clean + Flush item to disk + + <item IO completion> + + 9. Log item removed from AIL + Moves log tail + Item unlocked + +Essentially, steps 1-6 operate independently from step 7, which is also +independent of steps 8-9. An item can be locked in steps 1-6 or steps 8-9 +at the same time step 7 is occurring, but only steps 1-6 or 8-9 can occur +at the same time. If the log item is in the AIL or between steps 6 and 7 +and steps 1-6 are re-entered, then the item is relogged. Only when steps 8-9 +are entered and completed is the object considered clean. + +With delayed logging, there are new steps inserted into the life cycle: + + 1. Transaction allocate + 2. Transaction reserve + 3. Lock item + 4. Join item to transaction + If not already attached, + Allocate log item + Attach log item to owner item + Attach log item to transaction + 5. Modify item + Record modifications in log item + 6. Transaction commit + Pin item in memory if not pinned in CIL + Format item into log vector + buffer + Attach log vector and buffer to log item + Insert log item into CIL + Write CIL context sequence into transaction + Unlock item + + <next log force> + + 7. CIL push + lock CIL flush + Chain log vectors and buffers together + Remove items from CIL + unlock CIL flush + write log vectors into log + sequence commit records + attach checkpoint context to log buffer + + <log buffer IO dispatched> + <log buffer IO completes> + + 8. Checkpoint completion + Mark log item committed + Insert item into AIL + Write commit LSN into log item + Unpin log item + 9. AIL traversal + Lock item + Mark log item clean + Flush item to disk + <item IO completion> + 10. Log item removed from AIL + Moves log tail + Item unlocked + +From this, it can be seen that the only life cycle differences between the two +logging methods are in the middle of the life cycle - they still have the same +beginning and end and execution constraints. The only differences are in the +commiting of the log items to the log itself and the completion processing. +Hence delayed logging should not introduce any constraints on log item +behaviour, allocation or freeing that don't already exist. + +As a result of this zero-impact "insertion" of delayed logging infrastructure +and the design of the internal structures to avoid on disk format changes, we +can basically switch between delayed logging and the existing mechanism with a +mount option. Fundamentally, there is no reason why the log manager would not +be able to swap methods automatically and transparently depending on load +characteristics, but this should not be necessary if delayed logging works as +designed. + +Roadmap: + +2.6.35 Inclusion in mainline as an experimental mount option + => approximately 2-3 months to merge window + => needs to be in xfs-dev tree in 4-6 weeks + => code is nearing readiness for review + +2.6.37 Remove experimental tag from mount option + => should be roughly 6 months after initial merge + => enough time to: + => gain confidence and fix problems reported by early + adopters (a.k.a. guinea pigs) + => address worst performance regressions and undesired + behaviours + => start tuning/optimising code for parallelism + => start tuning/optimising algorithms consuming + excessive CPU time + +2.6.39 Switch default mount option to use delayed logging + => should be roughly 12 months after initial merge + => enough time to shake out remaining problems before next round of + enterprise distro kernel rebases diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile index b4769e4..c8fb13f 100644 --- a/fs/xfs/Makefile +++ b/fs/xfs/Makefile @@ -77,6 +77,7 @@ xfs-y += xfs_alloc.o \ xfs_itable.o \ xfs_dfrag.o \ xfs_log.o \ + xfs_log_cil.o \ xfs_log_recover.o \ xfs_mount.o \ xfs_mru_cache.o \ diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index f01de3c..649ade8 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -37,6 +37,7 @@ #include "xfs_sb.h" #include "xfs_inum.h" +#include "xfs_log.h" #include "xfs_ag.h" #include "xfs_dmapi.h" #include "xfs_mount.h" @@ -850,6 +851,12 @@ xfs_buf_lock_value( * Note that this in no way locks the underlying pages, so it is only * useful for synchronizing concurrent use of buffer objects, not for * synchronizing independent access to the underlying pages. + * + * If we come across a stale, pinned, locked buffer, we know that we + * are being asked to lock a buffer that has been reallocated. Because + * it is pinned, we know that the log has not been pushed to disk and + * hence it will still be locked. Rather than sleeping until someone + * else pushes the log, push it ourselves before trying to get the lock. */ void xfs_buf_lock( @@ -857,6 +864,8 @@ xfs_buf_lock( { trace_xfs_buf_lock(bp, _RET_IP_); + if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) + xfs_log_force(bp->b_mount, 0); if (atomic_read(&bp->b_io_remaining)) blk_run_address_space(bp->b_target->bt_mapping); down(&bp->b_sema); diff --git a/fs/xfs/linux-2.6/xfs_quotaops.c b/fs/xfs/linux-2.6/xfs_quotaops.c index e31bf21..9ac8aea 100644 --- a/fs/xfs/linux-2.6/xfs_quotaops.c +++ b/fs/xfs/linux-2.6/xfs_quotaops.c @@ -19,6 +19,7 @@ #include "xfs_dmapi.h" #include "xfs_sb.h" #include "xfs_inum.h" +#include "xfs_log.h" #include "xfs_ag.h" #include "xfs_mount.h" #include "xfs_quota.h" diff --git a/fs/xfs/linux-2.6/xfs_super.c b/fs/xfs/linux-2.6/xfs_super.c index f24dbe5..f2d1718 100644 --- a/fs/xfs/linux-2.6/xfs_super.c +++ b/fs/xfs/linux-2.6/xfs_super.c @@ -119,6 +119,8 @@ mempool_t *xfs_ioend_pool; #define MNTOPT_DMAPI "dmapi" /* DMI enabled (DMAPI / XDSM) */ #define MNTOPT_XDSM "xdsm" /* DMI enabled (DMAPI / XDSM) */ #define MNTOPT_DMI "dmi" /* DMI enabled (DMAPI / XDSM) */ +#define MNTOPT_DELAYLOG "delaylog" /* Delayed loging enabled */ +#define MNTOPT_NODELAYLOG "nodelaylog" /* Delayed loging disabled */ /* * Table driven mount option parser. @@ -374,6 +376,13 @@ xfs_parseargs( mp->m_flags |= XFS_MOUNT_DMAPI; } else if (!strcmp(this_char, MNTOPT_DMI)) { mp->m_flags |= XFS_MOUNT_DMAPI; + } else if (!strcmp(this_char, MNTOPT_DELAYLOG)) { + mp->m_flags |= XFS_MOUNT_DELAYLOG; + cmn_err(CE_WARN, + "Enabling EXPERIMENTAL delayed logging feature " + "- use at your own risk.\n"); + } else if (!strcmp(this_char, MNTOPT_NODELAYLOG)) { + mp->m_flags &= ~XFS_MOUNT_DELAYLOG; } else if (!strcmp(this_char, "ihashsize")) { cmn_err(CE_WARN, "XFS: ihashsize no longer used, option is deprecated."); @@ -535,6 +544,7 @@ xfs_showargs( { XFS_MOUNT_FILESTREAMS, "," MNTOPT_FILESTREAM }, { XFS_MOUNT_DMAPI, "," MNTOPT_DMAPI }, { XFS_MOUNT_GRPID, "," MNTOPT_GRPID }, + { XFS_MOUNT_DELAYLOG, "," MNTOPT_DELAYLOG }, { 0, NULL } }; static struct proc_xfs_info xfs_info_unset[] = { @@ -1755,7 +1765,7 @@ xfs_init_zones(void) * but it is much faster. */ xfs_buf_item_zone = kmem_zone_init((sizeof(xfs_buf_log_item_t) + - (((XFS_MAX_BLOCKSIZE / XFS_BLI_CHUNK) / + (((XFS_MAX_BLOCKSIZE / XFS_BLF_CHUNK) / NBWORD) * sizeof(int))), "xfs_buf_item"); if (!xfs_buf_item_zone) goto out_destroy_trans_zone; diff --git a/fs/xfs/linux-2.6/xfs_trace.h b/fs/xfs/linux-2.6/xfs_trace.h index 8a319cf..ff6bc79 100644 --- a/fs/xfs/linux-2.6/xfs_trace.h +++ b/fs/xfs/linux-2.6/xfs_trace.h @@ -1059,83 +1059,112 @@ TRACE_EVENT(xfs_bunmap, ); +#define XFS_BUSY_SYNC \ + { 0, "async" }, \ + { 1, "sync" } + TRACE_EVENT(xfs_alloc_busy, - TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, xfs_agblock_t agbno, - xfs_extlen_t len, int slot), - TP_ARGS(mp, agno, agbno, len, slot), + TP_PROTO(struct xfs_trans *trans, xfs_agnumber_t agno, + xfs_agblock_t agbno, xfs_extlen_t len, int sync), + TP_ARGS(trans, agno, agbno, len, sync), TP_STRUCT__entry( __field(dev_t, dev) + __field(struct xfs_trans *, tp) + __field(int, tid) __field(xfs_agnumber_t, agno) __field(xfs_agblock_t, agbno) __field(xfs_extlen_t, len) - __field(int, slot) + __field(int, sync) ), TP_fast_assign( - __entry->dev = mp->m_super->s_dev; + __entry->dev = trans->t_mountp->m_super->s_dev; + __entry->tp = trans; + __entry->tid = trans->t_ticket->t_tid; __entry->agno = agno; __entry->agbno = agbno; __entry->len = len; - __entry->slot = slot; + __entry->sync = sync; ), - TP_printk("dev %d:%d agno %u agbno %u len %u slot %d", + TP_printk("dev %d:%d trans 0x%p tid 0x%x agno %u agbno %u len %u %s", MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->tp, + __entry->tid, __entry->agno, __entry->agbno, __entry->len, - __entry->slot) + __print_symbolic(__entry->sync, XFS_BUSY_SYNC)) ); -#define XFS_BUSY_STATES \ - { 0, "found" }, \ - { 1, "missing" } - TRACE_EVENT(xfs_alloc_unbusy, TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, - int slot, int found), - TP_ARGS(mp, agno, slot, found), + xfs_agblock_t agbno, xfs_extlen_t len), + TP_ARGS(mp, agno, agbno, len), TP_STRUCT__entry( __field(dev_t, dev) __field(xfs_agnumber_t, agno) - __field(int, slot) - __field(int, found) + __field(xfs_agblock_t, agbno) + __field(xfs_extlen_t, len) ), TP_fast_assign( __entry->dev = mp->m_super->s_dev; __entry->agno = agno; - __entry->slot = slot; - __entry->found = found; + __entry->agbno = agbno; + __entry->len = len; ), - TP_printk("dev %d:%d agno %u slot %d %s", + TP_printk("dev %d:%d agno %u agbno %u len %u", MAJOR(__entry->dev), MINOR(__entry->dev), __entry->agno, - __entry->slot, - __print_symbolic(__entry->found, XFS_BUSY_STATES)) + __entry->agbno, + __entry->len) ); +#define XFS_BUSY_STATES \ + { 0, "missing" }, \ + { 1, "found" } + TRACE_EVENT(xfs_alloc_busysearch, - TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, xfs_agblock_t agbno, - xfs_extlen_t len, xfs_lsn_t lsn), - TP_ARGS(mp, agno, agbno, len, lsn), + TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, + xfs_agblock_t agbno, xfs_extlen_t len, int found), + TP_ARGS(mp, agno, agbno, len, found), TP_STRUCT__entry( __field(dev_t, dev) __field(xfs_agnumber_t, agno) __field(xfs_agblock_t, agbno) __field(xfs_extlen_t, len) - __field(xfs_lsn_t, lsn) + __field(int, found) ), TP_fast_assign( __entry->dev = mp->m_super->s_dev; __entry->agno = agno; __entry->agbno = agbno; __entry->len = len; - __entry->lsn = lsn; + __entry->found = found; ), - TP_printk("dev %d:%d agno %u agbno %u len %u force lsn 0x%llx", + TP_printk("dev %d:%d agno %u agbno %u len %u %s", MAJOR(__entry->dev), MINOR(__entry->dev), __entry->agno, __entry->agbno, __entry->len, + __print_symbolic(__entry->found, XFS_BUSY_STATES)) +); + +TRACE_EVENT(xfs_trans_commit_lsn, + TP_PROTO(struct xfs_trans *trans), + TP_ARGS(trans), + TP_STRUCT__entry( + __field(dev_t, dev) + __field(struct xfs_trans *, tp) + __field(xfs_lsn_t, lsn) + ), + TP_fast_assign( + __entry->dev = trans->t_mountp->m_super->s_dev; + __entry->tp = trans; + __entry->lsn = trans->t_commit_lsn; + ), + TP_printk("dev %d:%d trans 0x%p commit_lsn 0x%llx", + MAJOR(__entry->dev), MINOR(__entry->dev), + __entry->tp, __entry->lsn) ); diff --git a/fs/xfs/quota/xfs_dquot.c b/fs/xfs/quota/xfs_dquot.c index b89ec5d..585e763 100644 --- a/fs/xfs/quota/xfs_dquot.c +++ b/fs/xfs/quota/xfs_dquot.c @@ -344,9 +344,9 @@ xfs_qm_init_dquot_blk( for (i = 0; i < q->qi_dqperchunk; i++, d++, curid++) xfs_qm_dqinit_core(curid, type, d); xfs_trans_dquot_buf(tp, bp, - (type & XFS_DQ_USER ? XFS_BLI_UDQUOT_BUF : - ((type & XFS_DQ_PROJ) ? XFS_BLI_PDQUOT_BUF : - XFS_BLI_GDQUOT_BUF))); + (type & XFS_DQ_USER ? XFS_BLF_UDQUOT_BUF : + ((type & XFS_DQ_PROJ) ? XFS_BLF_PDQUOT_BUF : + XFS_BLF_GDQUOT_BUF))); xfs_trans_log_buf(tp, bp, 0, BBTOB(q->qi_dqchunklen) - 1); } diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h index abb8222..401f364 100644 --- a/fs/xfs/xfs_ag.h +++ b/fs/xfs/xfs_ag.h @@ -175,14 +175,20 @@ typedef struct xfs_agfl { } xfs_agfl_t; /* - * Busy block/extent entry. Used in perag to mark blocks that have been freed - * but whose transactions aren't committed to disk yet. + * Busy block/extent entry. Indexed by a rbtree in perag to mark blocks that + * have been freed but whose transactions aren't committed to disk yet. + * + * Note that we use the transaction ID to record the transaction, not the + * transaction structure itself. See xfs_alloc_busy_insert() for details. */ -typedef struct xfs_perag_busy { - xfs_agblock_t busy_start; - xfs_extlen_t busy_length; - struct xfs_trans *busy_tp; /* transaction that did the free */ -} xfs_perag_busy_t; +struct xfs_busy_extent { + struct rb_node rb_node; /* ag by-bno indexed search tree */ + struct list_head list; /* transaction busy extent list */ + xfs_agnumber_t agno; + xfs_agblock_t bno; + xfs_extlen_t length; + xlog_tid_t tid; /* transaction that created this */ +}; /* * Per-ag incore structure, copies of information in agf and agi, @@ -216,7 +222,8 @@ typedef struct xfs_perag { xfs_agino_t pagl_leftrec; xfs_agino_t pagl_rightrec; #ifdef __KERNEL__ - spinlock_t pagb_lock; /* lock for pagb_list */ + spinlock_t pagb_lock; /* lock for pagb_tree */ + struct rb_root pagb_tree; /* ordered tree of busy extents */ atomic_t pagf_fstrms; /* # of filestreams active in this AG */ @@ -226,7 +233,6 @@ typedef struct xfs_perag { int pag_ici_reclaimable; /* reclaimable inodes */ #endif int pagb_count; /* pagb slots in use */ - xfs_perag_busy_t pagb_list[XFS_PAGB_NUM_SLOTS]; /* unstable blocks */ } xfs_perag_t; /* diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c index 94cddbf..a7fbe8a 100644 --- a/fs/xfs/xfs_alloc.c +++ b/fs/xfs/xfs_alloc.c @@ -46,11 +46,9 @@ #define XFSA_FIXUP_BNO_OK 1 #define XFSA_FIXUP_CNT_OK 2 -STATIC void -xfs_alloc_search_busy(xfs_trans_t *tp, - xfs_agnumber_t agno, - xfs_agblock_t bno, - xfs_extlen_t len); +static int +xfs_alloc_busy_search(struct xfs_mount *mp, xfs_agnumber_t agno, + xfs_agblock_t bno, xfs_extlen_t len); /* * Prototypes for per-ag allocation routines @@ -540,9 +538,16 @@ xfs_alloc_ag_vextent( be32_to_cpu(agf->agf_length)); xfs_alloc_log_agf(args->tp, args->agbp, XFS_AGF_FREEBLKS); - /* search the busylist for these blocks */ - xfs_alloc_search_busy(args->tp, args->agno, - args->agbno, args->len); + /* + * Search the busylist for these blocks and mark the + * transaction as synchronous if blocks are found. This + * avoids the need to block due to a synchronous log + * force to ensure correct ordering as the synchronous + * transaction will guarantee that for us. + */ + if (xfs_alloc_busy_search(args->mp, args->agno, + args->agbno, args->len)) + xfs_trans_set_sync(args->tp); } if (!args->isfl) xfs_trans_mod_sb(args->tp, @@ -1693,7 +1698,7 @@ xfs_free_ag_extent( * when the iclog commits to disk. If a busy block is allocated, * the iclog is pushed up to the LSN that freed the block. */ - xfs_alloc_mark_busy(tp, agno, bno, len); + xfs_alloc_busy_insert(tp, agno, bno, len); return 0; error0: @@ -1989,14 +1994,20 @@ xfs_alloc_get_freelist( *bnop = bno; /* - * As blocks are freed, they are added to the per-ag busy list - * and remain there until the freeing transaction is committed to - * disk. Now that we have allocated blocks, this list must be - * searched to see if a block is being reused. If one is, then - * the freeing transaction must be pushed to disk NOW by forcing - * to disk all iclogs up that transaction's LSN. + * As blocks are freed, they are added to the per-ag busy list and + * remain there until the freeing transaction is committed to disk. + * Now that we have allocated blocks, this list must be searched to see + * if a block is being reused. If one is, then the freeing transaction + * must be pushed to disk before this transaction. + * + * We do this by setting the current transaction to a sync transaction + * which guarantees that the freeing transaction is on disk before this + * transaction. This is done instead of a synchronous log force here so + * that we don't sit and wait with the AGF locked in the transaction + * during the log force. */ - xfs_alloc_search_busy(tp, be32_to_cpu(agf->agf_seqno), bno, 1); + if (xfs_alloc_busy_search(mp, be32_to_cpu(agf->agf_seqno), bno, 1)) + xfs_trans_set_sync(tp); return 0; } @@ -2201,7 +2212,7 @@ xfs_alloc_read_agf( be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]); spin_lock_init(&pag->pagb_lock); pag->pagb_count = 0; - memset(pag->pagb_list, 0, sizeof(pag->pagb_list)); + pag->pagb_tree = RB_ROOT; pag->pagf_init = 1; } #ifdef DEBUG @@ -2479,127 +2490,263 @@ error0: * list is reused, the transaction that freed it must be forced to disk * before continuing to use the block. * - * xfs_alloc_mark_busy - add to the per-ag busy list - * xfs_alloc_clear_busy - remove an item from the per-ag busy list + * xfs_alloc_busy_insert - add to the per-ag busy list + * xfs_alloc_busy_clear - remove an item from the per-ag busy list + * xfs_alloc_busy_search - search for a busy extent + */ + +/* + * Insert a new extent into the busy tree. + * + * The busy extent tree is indexed by the start block of the busy extent. + * there can be multiple overlapping ranges in the busy extent tree but only + * ever one entry at a given start block. The reason for this is that + * multi-block extents can be freed, then smaller chunks of that extent + * allocated and freed again before the first transaction commit is on disk. + * If the exact same start block is freed a second time, we have to wait for + * that busy extent to pass out of the tree before the new extent is inserted. + * There are two main cases we have to handle here. + * + * The first case is a transaction that triggers a "free - allocate - free" + * cycle. This can occur during btree manipulations as a btree block is freed + * to the freelist, then allocated from the free list, then freed again. In + * this case, the second extxpnet free is what triggers the duplicate and as + * such the transaction IDs should match. Because the extent was allocated in + * this transaction, the transaction must be marked as synchronous. This is + * true for all cases where the free/alloc/free occurs in the one transaction, + * hence the addition of the ASSERT(tp->t_flags & XFS_TRANS_SYNC) to this case. + * This serves to catch violations of the second case quite effectively. + * + * The second case is where the free/alloc/free occur in different + * transactions. In this case, the thread freeing the extent the second time + * can't mark the extent busy immediately because it is already tracked in a + * transaction that may be committing. When the log commit for the existing + * busy extent completes, the busy extent will be removed from the tree. If we + * allow the second busy insert to continue using that busy extent structure, + * it can be freed before this transaction is safely in the log. Hence our + * only option in this case is to force the log to remove the existing busy + * extent from the list before we insert the new one with the current + * transaction ID. + * + * The problem we are trying to avoid in the free-alloc-free in separate + * transactions is most easily described with a timeline: + * + * Thread 1 Thread 2 Thread 3 xfslogd + * xact alloc + * free X + * mark busy + * commit xact + * free xact + * xact alloc + * alloc X + * busy search + * mark xact sync + * commit xact + * free xact + * force log + * checkpoint starts + * .... + * xact alloc + * free X + * mark busy + * finds match + * *** KABOOM! *** + * .... + * log IO completes + * unbusy X + * checkpoint completes + * + * By issuing a log force in thread 3 @ "KABOOM", the thread will block until + * the checkpoint completes, and the busy extent it matched will have been + * removed from the tree when it is woken. Hence it can then continue safely. + * + * However, to ensure this matching process is robust, we need to use the + * transaction ID for identifying transaction, as delayed logging results in + * the busy extent and transaction lifecycles being different. i.e. the busy + * extent is active for a lot longer than the transaction. Hence the + * transaction structure can be freed and reallocated, then mark the same + * extent busy again in the new transaction. In this case the new transaction + * will have a different tid but can have the same address, and hence we need + * to check against the tid. + * + * Future: for delayed logging, we could avoid the log force if the extent was + * first freed in the current checkpoint sequence. This, however, requires the + * ability to pin the current checkpoint in memory until this transaction + * commits to ensure that both the original free and the current one combine + * logically into the one checkpoint. If the checkpoint sequences are + * different, however, we still need to wait on a log force. */ void -xfs_alloc_mark_busy(xfs_trans_t *tp, - xfs_agnumber_t agno, - xfs_agblock_t bno, - xfs_extlen_t len) +xfs_alloc_busy_insert( + struct xfs_trans *tp, + xfs_agnumber_t agno, + xfs_agblock_t bno, + xfs_extlen_t len) { - xfs_perag_busy_t *bsy; + struct xfs_busy_extent *new; + struct xfs_busy_extent *busyp; struct xfs_perag *pag; - int n; + struct rb_node **rbp; + struct rb_node *parent; + int match; - pag = xfs_perag_get(tp->t_mountp, agno); - spin_lock(&pag->pagb_lock); - /* search pagb_list for an open slot */ - for (bsy = pag->pagb_list, n = 0; - n < XFS_PAGB_NUM_SLOTS; - bsy++, n++) { - if (bsy->busy_tp == NULL) { - break; - } + new = kmem_zalloc(sizeof(struct xfs_busy_extent), KM_MAYFAIL); + if (!new) { + /* + * No Memory! Since it is now not possible to track the free + * block, make this a synchronous transaction to insure that + * the block is not reused before this transaction commits. + */ + trace_xfs_alloc_busy(tp, agno, bno, len, 1); + xfs_trans_set_sync(tp); + return; } - trace_xfs_alloc_busy(tp->t_mountp, agno, bno, len, n); + new->agno = agno; + new->bno = bno; + new->length = len; + new->tid = xfs_log_get_trans_ident(tp); - if (n < XFS_PAGB_NUM_SLOTS) { - bsy = &pag->pagb_list[n]; - pag->pagb_count++; - bsy->busy_start = bno; - bsy->busy_length = len; - bsy->busy_tp = tp; - xfs_trans_add_busy(tp, agno, n); - } else { + INIT_LIST_HEAD(&new->list); + + /* trace before insert to be able to see failed inserts */ + trace_xfs_alloc_busy(tp, agno, bno, len, 0); + + pag = xfs_perag_get(tp->t_mountp, new->agno); +restart: + spin_lock(&pag->pagb_lock); + rbp = &pag->pagb_tree.rb_node; + parent = NULL; + busyp = NULL; + match = 0; + while (*rbp && match >= 0) { + parent = *rbp; + busyp = rb_entry(parent, struct xfs_busy_extent, rb_node); + + if (new->bno < busyp->bno) { + /* may overlap, but exact start block is lower */ + rbp = &(*rbp)->rb_left; + if (new->bno + new->length > busyp->bno) + match = busyp->tid == new->tid ? 1 : -1; + } else if (new->bno > busyp->bno) { + /* may overlap, but exact start block is higher */ + rbp = &(*rbp)->rb_right; + if (bno < busyp->bno + busyp->length) + match = busyp->tid == new->tid ? 1 : -1; + } else { + match = busyp->tid == new->tid ? 1 : -1; + break; + } + } + if (match < 0) { + /* overlap marked busy in different transaction */ + spin_unlock(&pag->pagb_lock); + xfs_log_force(tp->t_mountp, XFS_LOG_SYNC); + goto restart; + } + if (match > 0) { /* - * The busy list is full! Since it is now not possible to - * track the free block, make this a synchronous transaction - * to insure that the block is not reused before this - * transaction commits. + * overlap marked busy in same transaction. Update if exact + * start block match, otherwise combine the busy extents into + * a single range. */ - xfs_trans_set_sync(tp); - } + if (busyp->bno == new->bno) { + busyp->length = max(busyp->length, new->length); + spin_unlock(&pag->pagb_lock); + ASSERT(tp->t_flags & XFS_TRANS_SYNC); + xfs_perag_put(pag); + kmem_free(new); + return; + } + rb_erase(&busyp->rb_node, &pag->pagb_tree); + new->length = max(busyp->bno + busyp->length, + new->bno + new->length) - + min(busyp->bno, new->bno); + new->bno = min(busyp->bno, new->bno); + } else + busyp = NULL; + rb_link_node(&new->rb_node, parent, rbp); + rb_insert_color(&new->rb_node, &pag->pagb_tree); + + list_add(&new->list, &tp->t_busy); spin_unlock(&pag->pagb_lock); xfs_perag_put(pag); + kmem_free(busyp); } -void -xfs_alloc_clear_busy(xfs_trans_t *tp, - xfs_agnumber_t agno, - int idx) +/* + * Search for a busy extent within the range of the extent we are about to + * allocate. You need to be holding the busy extent tree lock when calling + * xfs_alloc_busy_search(). This function returns 0 for no overlapping busy + * extent, -1 for an overlapping but not exact busy extent, and 1 for an exact + * match. This is done so that a non-zero return indicates an overlap that + * will require a synchronous transaction, but it can still be + * used to distinguish between a partial or exact match. + */ +static int +xfs_alloc_busy_search( + struct xfs_mount *mp, + xfs_agnumber_t agno, + xfs_agblock_t bno, + xfs_extlen_t len) { struct xfs_perag *pag; - xfs_perag_busy_t *list; + struct rb_node *rbp; + struct xfs_busy_extent *busyp; + int match = 0; - ASSERT(idx < XFS_PAGB_NUM_SLOTS); - pag = xfs_perag_get(tp->t_mountp, agno); + pag = xfs_perag_get(mp, agno); spin_lock(&pag->pagb_lock); - list = pag->pagb_list; - trace_xfs_alloc_unbusy(tp->t_mountp, agno, idx, list[idx].busy_tp == tp); - - if (list[idx].busy_tp == tp) { - list[idx].busy_tp = NULL; - pag->pagb_count--; + rbp = pag->pagb_tree.rb_node; + + /* find closest start bno overlap */ + while (rbp) { + busyp = rb_entry(rbp, struct xfs_busy_extent, rb_node); + if (bno < busyp->bno) { + /* may overlap, but exact start block is lower */ + if (bno + len > busyp->bno) + match = -1; + rbp = rbp->rb_left; + } else if (bno > busyp->bno) { + /* may overlap, but exact start block is higher */ + if (bno < busyp->bno + busyp->length) + match = -1; + rbp = rbp->rb_right; + } else { + /* bno matches busyp, length determines exact match */ + match = (busyp->length == len) ? 1 : -1; + break; + } } - spin_unlock(&pag->pagb_lock); + trace_xfs_alloc_busysearch(mp, agno, bno, len, !!match); xfs_perag_put(pag); + return match; } - -/* - * If we find the extent in the busy list, force the log out to get the - * extent out of the busy list so the caller can use it straight away. - */ -STATIC void -xfs_alloc_search_busy(xfs_trans_t *tp, - xfs_agnumber_t agno, - xfs_agblock_t bno, - xfs_extlen_t len) +void +xfs_alloc_busy_clear( + struct xfs_mount *mp, + struct xfs_busy_extent *busyp) { struct xfs_perag *pag; - xfs_perag_busy_t *bsy; - xfs_agblock_t uend, bend; - xfs_lsn_t lsn = 0; - int cnt; - pag = xfs_perag_get(tp->t_mountp, agno); - spin_lock(&pag->pagb_lock); - cnt = pag->pagb_count; + trace_xfs_alloc_unbusy(mp, busyp->agno, busyp->bno, + busyp->length); - /* - * search pagb_list for this slot, skipping open slots. We have to - * search the entire array as there may be multiple overlaps and - * we have to get the most recent LSN for the log force to push out - * all the transactions that span the range. - */ - uend = bno + len - 1; - for (cnt = 0; cnt < pag->pagb_count; cnt++) { - bsy = &pag->pagb_list[cnt]; - if (!bsy->busy_tp) - continue; + ASSERT(xfs_alloc_busy_search(mp, busyp->agno, busyp->bno, + busyp->length) == 1); - bend = bsy->busy_start + bsy->busy_length - 1; - if (bno > bend || uend < bsy->busy_start) - continue; + list_del_init(&busyp->list); - /* (start1,length1) within (start2, length2) */ - if (XFS_LSN_CMP(bsy->busy_tp->t_commit_lsn, lsn) > 0) - lsn = bsy->busy_tp->t_commit_lsn; - } + pag = xfs_perag_get(mp, busyp->agno); + spin_lock(&pag->pagb_lock); + rb_erase(&busyp->rb_node, &pag->pagb_tree); spin_unlock(&pag->pagb_lock); xfs_perag_put(pag); - trace_xfs_alloc_busysearch(tp->t_mountp, agno, bno, len, lsn); - /* - * If a block was found, force the log through the LSN of the - * transaction that freed the block - */ - if (lsn) - xfs_log_force_lsn(tp->t_mountp, lsn, XFS_LOG_SYNC); + kmem_free(busyp); } diff --git a/fs/xfs/xfs_alloc.h b/fs/xfs/xfs_alloc.h index 599bffa..6d05199 100644 --- a/fs/xfs/xfs_alloc.h +++ b/fs/xfs/xfs_alloc.h @@ -22,6 +22,7 @@ struct xfs_buf; struct xfs_mount; struct xfs_perag; struct xfs_trans; +struct xfs_busy_extent; /* * Freespace allocation types. Argument to xfs_alloc_[v]extent. @@ -119,15 +120,13 @@ xfs_alloc_longest_free_extent(struct xfs_mount *mp, #ifdef __KERNEL__ void -xfs_alloc_mark_busy(xfs_trans_t *tp, +xfs_alloc_busy_insert(xfs_trans_t *tp, xfs_agnumber_t agno, xfs_agblock_t bno, xfs_extlen_t len); void -xfs_alloc_clear_busy(xfs_trans_t *tp, - xfs_agnumber_t ag, - int idx); +xfs_alloc_busy_clear(struct xfs_mount *mp, struct xfs_busy_extent *busyp); #endif /* __KERNEL__ */ diff --git a/fs/xfs/xfs_alloc_btree.c b/fs/xfs/xfs_alloc_btree.c index b726e10..83f4942 100644 --- a/fs/xfs/xfs_alloc_btree.c +++ b/fs/xfs/xfs_alloc_btree.c @@ -134,7 +134,7 @@ xfs_allocbt_free_block( * disk. If a busy block is allocated, the iclog is pushed up to the * LSN that freed the block. */ - xfs_alloc_mark_busy(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1); + xfs_alloc_busy_insert(cur->bc_tp, be32_to_cpu(agf->agf_seqno), bno, 1); xfs_trans_agbtree_delta(cur->bc_tp, -1); return 0; } diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c index 240340a..02a8098 100644 --- a/fs/xfs/xfs_buf_item.c +++ b/fs/xfs/xfs_buf_item.c @@ -64,7 +64,7 @@ xfs_buf_item_log_debug( nbytes = last - first + 1; bfset(bip->bli_logged, first, nbytes); for (x = 0; x < nbytes; x++) { - chunk_num = byte >> XFS_BLI_SHIFT; + chunk_num = byte >> XFS_BLF_SHIFT; word_num = chunk_num >> BIT_TO_WORD_SHIFT; bit_num = chunk_num & (NBWORD - 1); wordp = &(bip->bli_format.blf_data_map[word_num]); @@ -166,7 +166,7 @@ xfs_buf_item_size( * cancel flag in it. */ trace_xfs_buf_item_size_stale(bip); - ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); + ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); return 1; } @@ -197,9 +197,9 @@ xfs_buf_item_size( } else if (next_bit != last_bit + 1) { last_bit = next_bit; nvecs++; - } else if (xfs_buf_offset(bp, next_bit * XFS_BLI_CHUNK) != - (xfs_buf_offset(bp, last_bit * XFS_BLI_CHUNK) + - XFS_BLI_CHUNK)) { + } else if (xfs_buf_offset(bp, next_bit * XFS_BLF_CHUNK) != + (xfs_buf_offset(bp, last_bit * XFS_BLF_CHUNK) + + XFS_BLF_CHUNK)) { last_bit = next_bit; nvecs++; } else { @@ -254,6 +254,20 @@ xfs_buf_item_format( vecp++; nvecs = 1; + /* + * If it is an inode buffer, transfer the in-memory state to the + * format flags and clear the in-memory state. We do not transfer + * this state if the inode buffer allocation has not yet been committed + * to the log as setting the XFS_BLI_INODE_BUF flag will prevent + * correct replay of the inode allocation. + */ + if (bip->bli_flags & XFS_BLI_INODE_BUF) { + if (!((bip->bli_flags & XFS_BLI_INODE_ALLOC_BUF) && + xfs_log_item_in_current_chkpt(&bip->bli_item))) + bip->bli_format.blf_flags |= XFS_BLF_INODE_BUF; + bip->bli_flags &= ~XFS_BLI_INODE_BUF; + } + if (bip->bli_flags & XFS_BLI_STALE) { /* * The buffer is stale, so all we need to log @@ -261,7 +275,7 @@ xfs_buf_item_format( * cancel flag in it. */ trace_xfs_buf_item_format_stale(bip); - ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); + ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); bip->bli_format.blf_size = nvecs; return; } @@ -294,28 +308,28 @@ xfs_buf_item_format( * keep counting and scanning. */ if (next_bit == -1) { - buffer_offset = first_bit * XFS_BLI_CHUNK; + buffer_offset = first_bit * XFS_BLF_CHUNK; vecp->i_addr = xfs_buf_offset(bp, buffer_offset); - vecp->i_len = nbits * XFS_BLI_CHUNK; + vecp->i_len = nbits * XFS_BLF_CHUNK; vecp->i_type = XLOG_REG_TYPE_BCHUNK; nvecs++; break; } else if (next_bit != last_bit + 1) { - buffer_offset = first_bit * XFS_BLI_CHUNK; + buffer_offset = first_bit * XFS_BLF_CHUNK; vecp->i_addr = xfs_buf_offset(bp, buffer_offset); - vecp->i_len = nbits * XFS_BLI_CHUNK; + vecp->i_len = nbits * XFS_BLF_CHUNK; vecp->i_type = XLOG_REG_TYPE_BCHUNK; nvecs++; vecp++; first_bit = next_bit; last_bit = next_bit; nbits = 1; - } else if (xfs_buf_offset(bp, next_bit << XFS_BLI_SHIFT) != - (xfs_buf_offset(bp, last_bit << XFS_BLI_SHIFT) + - XFS_BLI_CHUNK)) { - buffer_offset = first_bit * XFS_BLI_CHUNK; + } else if (xfs_buf_offset(bp, next_bit << XFS_BLF_SHIFT) != + (xfs_buf_offset(bp, last_bit << XFS_BLF_SHIFT) + + XFS_BLF_CHUNK)) { + buffer_offset = first_bit * XFS_BLF_CHUNK; vecp->i_addr = xfs_buf_offset(bp, buffer_offset); - vecp->i_len = nbits * XFS_BLI_CHUNK; + vecp->i_len = nbits * XFS_BLF_CHUNK; vecp->i_type = XLOG_REG_TYPE_BCHUNK; /* You would think we need to bump the nvecs here too, but we do not * this number is used by recovery, and it gets confused by the boundary @@ -341,10 +355,15 @@ xfs_buf_item_format( } /* - * This is called to pin the buffer associated with the buf log - * item in memory so it cannot be written out. Simply call bpin() - * on the buffer to do this. + * This is called to pin the buffer associated with the buf log item in memory + * so it cannot be written out. Simply call bpin() on the buffer to do this. + * + * We also always take a reference to the buffer log item here so that the bli + * is held while the item is pinned in memory. This means that we can + * unconditionally drop the reference count a transaction holds when the + * transaction is completed. */ + STATIC void xfs_buf_item_pin( xfs_buf_log_item_t *bip) @@ -356,6 +375,7 @@ xfs_buf_item_pin( ASSERT(atomic_read(&bip->bli_refcount) > 0); ASSERT((bip->bli_flags & XFS_BLI_LOGGED) || (bip->bli_flags & XFS_BLI_STALE)); + atomic_inc(&bip->bli_refcount); trace_xfs_buf_item_pin(bip); xfs_bpin(bp); } @@ -393,7 +413,7 @@ xfs_buf_item_unpin( ASSERT(XFS_BUF_VALUSEMA(bp) <= 0); ASSERT(!(XFS_BUF_ISDELAYWRITE(bp))); ASSERT(XFS_BUF_ISSTALE(bp)); - ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); + ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); trace_xfs_buf_item_unpin_stale(bip); /* @@ -489,20 +509,23 @@ xfs_buf_item_trylock( } /* - * Release the buffer associated with the buf log item. - * If there is no dirty logged data associated with the - * buffer recorded in the buf log item, then free the - * buf log item and remove the reference to it in the - * buffer. + * Release the buffer associated with the buf log item. If there is no dirty + * logged data associated with the buffer recorded in the buf log item, then + * free the buf log item and remove the reference to it in the buffer. + * + * This call ignores the recursion count. It is only called when the buffer + * should REALLY be unlocked, regardless of the recursion count. * - * This call ignores the recursion count. It is only called - * when the buffer should REALLY be unlocked, regardless - * of the recursion count. + * We unconditionally drop the transaction's reference to the log item. If the + * item was logged, then another reference was taken when it was pinned, so we + * can safely drop the transaction reference now. This also allows us to avoid + * potential races with the unpin code freeing the bli by not referencing the + * bli after we've dropped the reference count. * - * If the XFS_BLI_HOLD flag is set in the buf log item, then - * free the log item if necessary but do not unlock the buffer. - * This is for support of xfs_trans_bhold(). Make sure the - * XFS_BLI_HOLD field is cleared if we don't free the item. + * If the XFS_BLI_HOLD flag is set in the buf log item, then free the log item + * if necessary but do not unlock the buffer. This is for support of + * xfs_trans_bhold(). Make sure the XFS_BLI_HOLD field is cleared if we don't + * free the item. */ STATIC void xfs_buf_item_unlock( @@ -514,73 +537,54 @@ xfs_buf_item_unlock( bp = bip->bli_buf; - /* - * Clear the buffer's association with this transaction. - */ + /* Clear the buffer's association with this transaction. */ XFS_BUF_SET_FSPRIVATE2(bp, NULL); /* - * If this is a transaction abort, don't return early. - * Instead, allow the brelse to happen. - * Normally it would be done for stale (cancelled) buffers - * at unpin time, but we'll never go through the pin/unpin - * cycle if we abort inside commit. + * If this is a transaction abort, don't return early. Instead, allow + * the brelse to happen. Normally it would be done for stale + * (cancelled) buffers at unpin time, but we'll never go through the + * pin/unpin cycle if we abort inside commit. */ aborted = (bip->bli_item.li_flags & XFS_LI_ABORTED) != 0; /* - * If the buf item is marked stale, then don't do anything. - * We'll unlock the buffer and free the buf item when the - * buffer is unpinned for the last time. + * Before possibly freeing the buf item, determine if we should + * release the buffer at the end of this routine. */ - if (bip->bli_flags & XFS_BLI_STALE) { - bip->bli_flags &= ~XFS_BLI_LOGGED; - trace_xfs_buf_item_unlock_stale(bip); - ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); - if (!aborted) - return; - } + hold = bip->bli_flags & XFS_BLI_HOLD; + + /* Clear the per transaction state. */ + bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_HOLD); /* - * Drop the transaction's reference to the log item if - * it was not logged as part of the transaction. Otherwise - * we'll drop the reference in xfs_buf_item_unpin() when - * the transaction is really through with the buffer. + * If the buf item is marked stale, then don't do anything. We'll + * unlock the buffer and free the buf item when the buffer is unpinned + * for the last time. */ - if (!(bip->bli_flags & XFS_BLI_LOGGED)) { - atomic_dec(&bip->bli_refcount); - } else { - /* - * Clear the logged flag since this is per - * transaction state. - */ - bip->bli_flags &= ~XFS_BLI_LOGGED; + if (bip->bli_flags & XFS_BLI_STALE) { + trace_xfs_buf_item_unlock_stale(bip); + ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); + if (!aborted) { + atomic_dec(&bip->bli_refcount); + return; + } } - /* - * Before possibly freeing the buf item, determine if we should - * release the buffer at the end of this routine. - */ - hold = bip->bli_flags & XFS_BLI_HOLD; trace_xfs_buf_item_unlock(bip); /* - * If the buf item isn't tracking any data, free it. - * Otherwise, if XFS_BLI_HOLD is set clear it. + * If the buf item isn't tracking any data, free it, otherwise drop the + * reference we hold to it. */ if (xfs_bitmap_empty(bip->bli_format.blf_data_map, - bip->bli_format.blf_map_size)) { + bip->bli_format.blf_map_size)) xfs_buf_item_relse(bp); - } else if (hold) { - bip->bli_flags &= ~XFS_BLI_HOLD; - } + else + atomic_dec(&bip->bli_refcount); - /* - * Release the buffer if XFS_BLI_HOLD was not set. - */ - if (!hold) { + if (!hold) xfs_buf_relse(bp); - } } /* @@ -717,12 +721,12 @@ xfs_buf_item_init( } /* - * chunks is the number of XFS_BLI_CHUNK size pieces + * chunks is the number of XFS_BLF_CHUNK size pieces * the buffer can be divided into. Make sure not to * truncate any pieces. map_size is the size of the * bitmap needed to describe the chunks of the buffer. */ - chunks = (int)((XFS_BUF_COUNT(bp) + (XFS_BLI_CHUNK - 1)) >> XFS_BLI_SHIFT); + chunks = (int)((XFS_BUF_COUNT(bp) + (XFS_BLF_CHUNK - 1)) >> XFS_BLF_SHIFT); map_size = (int)((chunks + NBWORD) >> BIT_TO_WORD_SHIFT); bip = (xfs_buf_log_item_t*)kmem_zone_zalloc(xfs_buf_item_zone, @@ -790,8 +794,8 @@ xfs_buf_item_log( /* * Convert byte offsets to bit numbers. */ - first_bit = first >> XFS_BLI_SHIFT; - last_bit = last >> XFS_BLI_SHIFT; + first_bit = first >> XFS_BLF_SHIFT; + last_bit = last >> XFS_BLF_SHIFT; /* * Calculate the total number of bits to be set. diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h index df44545..f20bb47 100644 --- a/fs/xfs/xfs_buf_item.h +++ b/fs/xfs/xfs_buf_item.h @@ -41,22 +41,22 @@ typedef struct xfs_buf_log_format { * This flag indicates that the buffer contains on disk inodes * and requires special recovery handling. */ -#define XFS_BLI_INODE_BUF 0x1 +#define XFS_BLF_INODE_BUF 0x1 /* * This flag indicates that the buffer should not be replayed * during recovery because its blocks are being freed. */ -#define XFS_BLI_CANCEL 0x2 +#define XFS_BLF_CANCEL 0x2 /* * This flag indicates that the buffer contains on disk * user or group dquots and may require special recovery handling. */ -#define XFS_BLI_UDQUOT_BUF 0x4 -#define XFS_BLI_PDQUOT_BUF 0x8 -#define XFS_BLI_GDQUOT_BUF 0x10 +#define XFS_BLF_UDQUOT_BUF 0x4 +#define XFS_BLF_PDQUOT_BUF 0x8 +#define XFS_BLF_GDQUOT_BUF 0x10 -#define XFS_BLI_CHUNK 128 -#define XFS_BLI_SHIFT 7 +#define XFS_BLF_CHUNK 128 +#define XFS_BLF_SHIFT 7 #define BIT_TO_WORD_SHIFT 5 #define NBWORD (NBBY * sizeof(unsigned int)) @@ -69,6 +69,7 @@ typedef struct xfs_buf_log_format { #define XFS_BLI_LOGGED 0x08 #define XFS_BLI_INODE_ALLOC_BUF 0x10 #define XFS_BLI_STALE_INODE 0x20 +#define XFS_BLI_INODE_BUF 0x40 #define XFS_BLI_FLAGS \ { XFS_BLI_HOLD, "HOLD" }, \ @@ -76,7 +77,8 @@ typedef struct xfs_buf_log_format { { XFS_BLI_STALE, "STALE" }, \ { XFS_BLI_LOGGED, "LOGGED" }, \ { XFS_BLI_INODE_ALLOC_BUF, "INODE_ALLOC" }, \ - { XFS_BLI_STALE_INODE, "STALE_INODE" } + { XFS_BLI_STALE_INODE, "STALE_INODE" }, \ + { XFS_BLI_INODE_BUF, "INODE_BUF" } #ifdef __KERNEL__ diff --git a/fs/xfs/xfs_error.c b/fs/xfs/xfs_error.c index ef96175..047b8a8 100644 --- a/fs/xfs/xfs_error.c +++ b/fs/xfs/xfs_error.c @@ -170,7 +170,7 @@ xfs_cmn_err(int panic_tag, int level, xfs_mount_t *mp, char *fmt, ...) va_list ap; #ifdef DEBUG - xfs_panic_mask |= XFS_PTAG_SHUTDOWN_CORRUPT; + xfs_panic_mask |= (XFS_PTAG_SHUTDOWN_CORRUPT | XFS_PTAG_LOGRES); #endif if (xfs_panic_mask && (xfs_panic_mask & panic_tag) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 3038dd5..5215abc 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -54,9 +54,6 @@ STATIC xlog_t * xlog_alloc_log(xfs_mount_t *mp, STATIC int xlog_space_left(xlog_t *log, int cycle, int bytes); STATIC int xlog_sync(xlog_t *log, xlog_in_core_t *iclog); STATIC void xlog_dealloc_log(xlog_t *log); -STATIC int xlog_write(struct log *log, struct xfs_log_vec *log_vector, - struct xlog_ticket *tic, xfs_lsn_t *start_lsn, - xlog_in_core_t **commit_iclog, uint flags); /* local state machine functions */ STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int); @@ -86,14 +83,6 @@ STATIC int xlog_regrant_write_log_space(xlog_t *log, STATIC void xlog_ungrant_log_space(xlog_t *log, xlog_ticket_t *ticket); - -/* local ticket functions */ -STATIC xlog_ticket_t *xlog_ticket_alloc(xlog_t *log, - int unit_bytes, - int count, - char clientid, - uint flags); - #if defined(DEBUG) STATIC void xlog_verify_dest_ptr(xlog_t *log, char *ptr); STATIC void xlog_verify_grant_head(xlog_t *log, int equals); @@ -360,6 +349,15 @@ xfs_log_reserve( ASSERT(flags & XFS_LOG_PERM_RESERV); internal_ticket = *ticket; + /* + * this is a new transaction on the ticket, so we need to + * change the transaction ID so that the next transaction has a + * different TID in the log. Just add one to the existing tid + * so that we can see chains of rolling transactions in the log + * easily. + */ + internal_ticket->t_tid++; + trace_xfs_log_reserve(log, internal_ticket); xlog_grant_push_ail(mp, internal_ticket->t_unit_res); @@ -367,7 +365,8 @@ xfs_log_reserve( } else { /* may sleep if need to allocate more tickets */ internal_ticket = xlog_ticket_alloc(log, unit_bytes, cnt, - client, flags); + client, flags, + KM_SLEEP|KM_MAYFAIL); if (!internal_ticket) return XFS_ERROR(ENOMEM); internal_ticket->t_trans_type = t_type; @@ -452,6 +451,13 @@ xfs_log_mount( /* Normal transactions can now occur */ mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY; + /* + * Now the log has been fully initialised and we know were our + * space grant counters are, we can initialise the permanent ticket + * needed for delayed logging to work. + */ + xlog_cil_init_post_recovery(mp->m_log); + return 0; out_destroy_ail: @@ -658,6 +664,10 @@ xfs_log_item_init( item->li_ailp = mp->m_ail; item->li_type = type; item->li_ops = ops; + item->li_lv = NULL; + + INIT_LIST_HEAD(&item->li_ail); + INIT_LIST_HEAD(&item->li_cil); } /* @@ -1168,6 +1178,9 @@ xlog_alloc_log(xfs_mount_t *mp, *iclogp = log->l_iclog; /* complete ring */ log->l_iclog->ic_prev = prev_iclog; /* re-write 1st prev ptr */ + error = xlog_cil_init(log); + if (error) + goto out_free_iclog; return log; out_free_iclog: @@ -1494,6 +1507,8 @@ xlog_dealloc_log(xlog_t *log) xlog_in_core_t *iclog, *next_iclog; int i; + xlog_cil_destroy(log); + iclog = log->l_iclog; for (i=0; i<log->l_iclog_bufs; i++) { sv_destroy(&iclog->ic_force_wait); @@ -1536,8 +1551,10 @@ xlog_state_finish_copy(xlog_t *log, * print out info relating to regions written which consume * the reservation */ -STATIC void -xlog_print_tic_res(xfs_mount_t *mp, xlog_ticket_t *ticket) +void +xlog_print_tic_res( + struct xfs_mount *mp, + struct xlog_ticket *ticket) { uint i; uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t); @@ -1637,6 +1654,10 @@ xlog_print_tic_res(xfs_mount_t *mp, xlog_ticket_t *ticket) "bad-rtype" : res_type_str[r_type-1]), ticket->t_res_arr[i].r_len); } + + xfs_cmn_err(XFS_PTAG_LOGRES, CE_ALERT, mp, + "xfs_log_write: reservation ran out. Need to up reservation"); + xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE); } /* @@ -1865,7 +1886,7 @@ xlog_write_copy_finish( * we don't update ic_offset until the end when we know exactly how many * bytes have been written out. */ -STATIC int +int xlog_write( struct log *log, struct xfs_log_vec *log_vector, @@ -1889,22 +1910,26 @@ xlog_write( *start_lsn = 0; len = xlog_write_calc_vec_length(ticket, log_vector); - if (ticket->t_curr_res < len) { - xlog_print_tic_res(log->l_mp, ticket); -#ifdef DEBUG - xlog_panic( - "xfs_log_write: reservation ran out. Need to up reservation"); -#else - /* Customer configurable panic */ - xfs_cmn_err(XFS_PTAG_LOGRES, CE_ALERT, log->l_mp, - "xfs_log_write: reservation ran out. Need to up reservation"); + if (log->l_cilp) { + /* + * Region headers and bytes are already accounted for. + * We only need to take into account start records and + * split regions in this function. + */ + if (ticket->t_flags & XLOG_TIC_INITED) + ticket->t_curr_res -= sizeof(xlog_op_header_t); - /* If we did not panic, shutdown the filesystem */ - xfs_force_shutdown(log->l_mp, SHUTDOWN_CORRUPT_INCORE); -#endif - } + /* + * Commit record headers need to be accounted for. These + * come in as separate writes so are easy to detect. + */ + if (flags & (XLOG_COMMIT_TRANS | XLOG_UNMOUNT_TRANS)) + ticket->t_curr_res -= sizeof(xlog_op_header_t); + } else + ticket->t_curr_res -= len; - ticket->t_curr_res -= len; + if (ticket->t_curr_res < 0) + xlog_print_tic_res(log->l_mp, ticket); index = 0; lv = log_vector; @@ -3000,6 +3025,8 @@ _xfs_log_force( XFS_STATS_INC(xs_log_force); + xlog_cil_push(log, 1); + spin_lock(&log->l_icloglock); iclog = log->l_iclog; @@ -3149,6 +3176,12 @@ _xfs_log_force_lsn( XFS_STATS_INC(xs_log_force); + if (log->l_cilp) { + lsn = xlog_cil_push_lsn(log, lsn); + if (lsn == NULLCOMMITLSN) + return 0; + } + try_again: spin_lock(&log->l_icloglock); iclog = log->l_iclog; @@ -3313,22 +3346,30 @@ xfs_log_ticket_get( return ticket; } +xlog_tid_t +xfs_log_get_trans_ident( + struct xfs_trans *tp) +{ + return tp->t_ticket->t_tid; +} + /* * Allocate and initialise a new log ticket. */ -STATIC xlog_ticket_t * +xlog_ticket_t * xlog_ticket_alloc( struct log *log, int unit_bytes, int cnt, char client, - uint xflags) + uint xflags, + int alloc_flags) { struct xlog_ticket *tic; uint num_headers; int iclog_space; - tic = kmem_zone_zalloc(xfs_log_ticket_zone, KM_SLEEP|KM_MAYFAIL); + tic = kmem_zone_zalloc(xfs_log_ticket_zone, alloc_flags); if (!tic) return NULL; @@ -3647,6 +3688,11 @@ xlog_state_ioerror( * c. nothing new gets queued up after (a) and (b) are done. * d. if !logerror, flush the iclogs to disk, then seal them off * for business. + * + * Note: for delayed logging the !logerror case needs to flush the regions + * held in memory out to the iclogs before flushing them to disk. This needs + * to be done before the log is marked as shutdown, otherwise the flush to the + * iclogs will fail. */ int xfs_log_force_umount( @@ -3680,6 +3726,16 @@ xfs_log_force_umount( return 1; } retval = 0; + + /* + * Flush the in memory commit item list before marking the log as + * being shut down. We need to do it in this order to ensure all the + * completed transactions are flushed to disk with the xfs_log_force() + * call below. + */ + if (!logerror && (mp->m_flags & XFS_MOUNT_DELAYLOG)) + xlog_cil_push(log, 1); + /* * We must hold both the GRANT lock and the LOG lock, * before we mark the filesystem SHUTDOWN and wake diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h index 229d1f3..04c78e6 100644 --- a/fs/xfs/xfs_log.h +++ b/fs/xfs/xfs_log.h @@ -19,7 +19,6 @@ #define __XFS_LOG_H__ /* get lsn fields */ - #define CYCLE_LSN(lsn) ((uint)((lsn)>>32)) #define BLOCK_LSN(lsn) ((uint)(lsn)) @@ -114,6 +113,9 @@ struct xfs_log_vec { struct xfs_log_vec *lv_next; /* next lv in build list */ int lv_niovecs; /* number of iovecs in lv */ struct xfs_log_iovec *lv_iovecp; /* iovec array */ + struct xfs_log_item *lv_item; /* owner */ + char *lv_buf; /* formatted buffer */ + int lv_buf_len; /* size of formatted buffer */ }; /* @@ -134,6 +136,7 @@ struct xlog_in_core; struct xlog_ticket; struct xfs_log_item; struct xfs_item_ops; +struct xfs_trans; void xfs_log_item_init(struct xfs_mount *mp, struct xfs_log_item *item, @@ -187,9 +190,16 @@ int xfs_log_need_covered(struct xfs_mount *mp); void xlog_iodone(struct xfs_buf *); -struct xlog_ticket * xfs_log_ticket_get(struct xlog_ticket *ticket); +struct xlog_ticket *xfs_log_ticket_get(struct xlog_ticket *ticket); void xfs_log_ticket_put(struct xlog_ticket *ticket); +xlog_tid_t xfs_log_get_trans_ident(struct xfs_trans *tp); + +int xfs_log_commit_cil(struct xfs_mount *mp, struct xfs_trans *tp, + struct xfs_log_vec *log_vector, + xfs_lsn_t *commit_lsn, int flags); +bool xfs_log_item_in_current_chkpt(struct xfs_log_item *lip); + #endif diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c new file mode 100644 index 0000000..bb17cc0 --- /dev/null +++ b/fs/xfs/xfs_log_cil.c @@ -0,0 +1,725 @@ +/* + * Copyright (c) 2010 Red Hat, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "xfs.h" +#include "xfs_fs.h" +#include "xfs_types.h" +#include "xfs_bit.h" +#include "xfs_log.h" +#include "xfs_inum.h" +#include "xfs_trans.h" +#include "xfs_trans_priv.h" +#include "xfs_log_priv.h" +#include "xfs_sb.h" +#include "xfs_ag.h" +#include "xfs_dir2.h" +#include "xfs_dmapi.h" +#include "xfs_mount.h" +#include "xfs_error.h" +#include "xfs_alloc.h" + +/* + * Perform initial CIL structure initialisation. If the CIL is not + * enabled in this filesystem, ensure the log->l_cilp is null so + * we can check this conditional to determine if we are doing delayed + * logging or not. + */ +int +xlog_cil_init( + struct log *log) +{ + struct xfs_cil *cil; + struct xfs_cil_ctx *ctx; + + log->l_cilp = NULL; + if (!(log->l_mp->m_flags & XFS_MOUNT_DELAYLOG)) + return 0; + + cil = kmem_zalloc(sizeof(*cil), KM_SLEEP|KM_MAYFAIL); + if (!cil) + return ENOMEM; + + ctx = kmem_zalloc(sizeof(*ctx), KM_SLEEP|KM_MAYFAIL); + if (!ctx) { + kmem_free(cil); + return ENOMEM; + } + + INIT_LIST_HEAD(&cil->xc_cil); + INIT_LIST_HEAD(&cil->xc_committing); + spin_lock_init(&cil->xc_cil_lock); + init_rwsem(&cil->xc_ctx_lock); + sv_init(&cil->xc_commit_wait, SV_DEFAULT, "cilwait"); + + INIT_LIST_HEAD(&ctx->committing); + INIT_LIST_HEAD(&ctx->busy_extents); + ctx->sequence = 1; + ctx->cil = cil; + cil->xc_ctx = ctx; + + cil->xc_log = log; + log->l_cilp = cil; + return 0; +} + +void +xlog_cil_destroy( + struct log *log) +{ + if (!log->l_cilp) + return; + + if (log->l_cilp->xc_ctx) { + if (log->l_cilp->xc_ctx->ticket) + xfs_log_ticket_put(log->l_cilp->xc_ctx->ticket); + kmem_free(log->l_cilp->xc_ctx); + } + + ASSERT(list_empty(&log->l_cilp->xc_cil)); + kmem_free(log->l_cilp); +} + +/* + * Allocate a new ticket. Failing to get a new ticket makes it really hard to + * recover, so we don't allow failure here. Also, we allocate in a context that + * we don't want to be issuing transactions from, so we need to tell the + * allocation code this as well. + * + * We don't reserve any space for the ticket - we are going to steal whatever + * space we require from transactions as they commit. To ensure we reserve all + * the space required, we need to set the current reservation of the ticket to + * zero so that we know to steal the initial transaction overhead from the + * first transaction commit. + */ +static struct xlog_ticket * +xlog_cil_ticket_alloc( + struct log *log) +{ + struct xlog_ticket *tic; + + tic = xlog_ticket_alloc(log, 0, 1, XFS_TRANSACTION, 0, + KM_SLEEP|KM_NOFS); + tic->t_trans_type = XFS_TRANS_CHECKPOINT; + + /* + * set the current reservation to zero so we know to steal the basic + * transaction overhead reservation from the first transaction commit. + */ + tic->t_curr_res = 0; + return tic; +} + +/* + * After the first stage of log recovery is done, we know where the head and + * tail of the log are. We need this log initialisation done before we can + * initialise the first CIL checkpoint context. + * + * Here we allocate a log ticket to track space usage during a CIL push. This + * ticket is passed to xlog_write() directly so that we don't slowly leak log + * space by failing to account for space used by log headers and additional + * region headers for split regions. + */ +void +xlog_cil_init_post_recovery( + struct log *log) +{ + if (!log->l_cilp) + return; + + log->l_cilp->xc_ctx->ticket = xlog_cil_ticket_alloc(log); + log->l_cilp->xc_ctx->sequence = 1; + log->l_cilp->xc_ctx->commit_lsn = xlog_assign_lsn(log->l_curr_cycle, + log->l_curr_block); +} + +/* + * Insert the log item into the CIL and calculate the difference in space + * consumed by the item. Add the space to the checkpoint ticket and calculate + * if the change requires additional log metadata. If it does, take that space + * as well. Remove the amount of space we addded to the checkpoint ticket from + * the current transaction ticket so that the accounting works out correctly. + * + * If this is the first time the item is being placed into the CIL in this + * context, pin it so it can't be written to disk until the CIL is flushed to + * the iclog and the iclog written to disk. + */ +static void +xlog_cil_insert( + struct log *log, + struct xlog_ticket *ticket, + struct xfs_log_item *item, + struct xfs_log_vec *lv) +{ + struct xfs_cil *cil = log->l_cilp; + struct xfs_log_vec *old = lv->lv_item->li_lv; + struct xfs_cil_ctx *ctx = cil->xc_ctx; + int len; + int diff_iovecs; + int iclog_space; + + if (old) { + /* existing lv on log item, space used is a delta */ + ASSERT(!list_empty(&item->li_cil)); + ASSERT(old->lv_buf && old->lv_buf_len && old->lv_niovecs); + + len = lv->lv_buf_len - old->lv_buf_len; + diff_iovecs = lv->lv_niovecs - old->lv_niovecs; + kmem_free(old->lv_buf); + kmem_free(old); + } else { + /* new lv, must pin the log item */ + ASSERT(!lv->lv_item->li_lv); + ASSERT(list_empty(&item->li_cil)); + + len = lv->lv_buf_len; + diff_iovecs = lv->lv_niovecs; + IOP_PIN(lv->lv_item); + + } + len += diff_iovecs * sizeof(xlog_op_header_t); + + /* attach new log vector to log item */ + lv->lv_item->li_lv = lv; + + spin_lock(&cil->xc_cil_lock); + list_move_tail(&item->li_cil, &cil->xc_cil); + ctx->nvecs += diff_iovecs; + + /* + * If this is the first time the item is being committed to the CIL, + * store the sequence number on the log item so we can tell + * in future commits whether this is the first checkpoint the item is + * being committed into. + */ + if (!item->li_seq) + item->li_seq = ctx->sequence; + + /* + * Now transfer enough transaction reservation to the context ticket + * for the checkpoint. The context ticket is special - the unit + * reservation has to grow as well as the current reservation as we + * steal from tickets so we can correctly determine the space used + * during the transaction commit. + */ + if (ctx->ticket->t_curr_res == 0) { + /* first commit in checkpoint, steal the header reservation */ + ASSERT(ticket->t_curr_res >= ctx->ticket->t_unit_res + len); + ctx->ticket->t_curr_res = ctx->ticket->t_unit_res; + ticket->t_curr_res -= ctx->ticket->t_unit_res; + } + + /* do we need space for more log record headers? */ + iclog_space = log->l_iclog_size - log->l_iclog_hsize; + if (len > 0 && (ctx->space_used / iclog_space != + (ctx->space_used + len) / iclog_space)) { + int hdrs; + + hdrs = (len + iclog_space - 1) / iclog_space; + /* need to take into account split region headers, too */ + hdrs *= log->l_iclog_hsize + sizeof(struct xlog_op_header); + ctx->ticket->t_unit_res += hdrs; + ctx->ticket->t_curr_res += hdrs; + ticket->t_curr_res -= hdrs; + ASSERT(ticket->t_curr_res >= len); + } + ticket->t_curr_res -= len; + ctx->space_used += len; + + spin_unlock(&cil->xc_cil_lock); +} + +/* + * Format log item into a flat buffers + * + * For delayed logging, we need to hold a formatted buffer containing all the + * changes on the log item. This enables us to relog the item in memory and + * write it out asynchronously without needing to relock the object that was + * modified at the time it gets written into the iclog. + * + * This function builds a vector for the changes in each log item in the + * transaction. It then works out the length of the buffer needed for each log + * item, allocates them and formats the vector for the item into the buffer. + * The buffer is then attached to the log item are then inserted into the + * Committed Item List for tracking until the next checkpoint is written out. + * + * We don't set up region headers during this process; we simply copy the + * regions into the flat buffer. We can do this because we still have to do a + * formatting step to write the regions into the iclog buffer. Writing the + * ophdrs during the iclog write means that we can support splitting large + * regions across iclog boundares without needing a change in the format of the + * item/region encapsulation. + * + * Hence what we need to do now is change the rewrite the vector array to point + * to the copied region inside the buffer we just allocated. This allows us to + * format the regions into the iclog as though they are being formatted + * directly out of the objects themselves. + */ +static void +xlog_cil_format_items( + struct log *log, + struct xfs_log_vec *log_vector, + struct xlog_ticket *ticket, + xfs_lsn_t *start_lsn) +{ + struct xfs_log_vec *lv; + + if (start_lsn) + *start_lsn = log->l_cilp->xc_ctx->sequence; + + ASSERT(log_vector); + for (lv = log_vector; lv; lv = lv->lv_next) { + void *ptr; + int index; + int len = 0; + + /* build the vector array and calculate it's length */ + IOP_FORMAT(lv->lv_item, lv->lv_iovecp); + for (index = 0; index < lv->lv_niovecs; index++) + len += lv->lv_iovecp[index].i_len; + + lv->lv_buf_len = len; + lv->lv_buf = kmem_zalloc(lv->lv_buf_len, KM_SLEEP|KM_NOFS); + ptr = lv->lv_buf; + + for (index = 0; index < lv->lv_niovecs; index++) { + struct xfs_log_iovec *vec = &lv->lv_iovecp[index]; + + memcpy(ptr, vec->i_addr, vec->i_len); + vec->i_addr = ptr; + ptr += vec->i_len; + } + ASSERT(ptr == lv->lv_buf + lv->lv_buf_len); + + xlog_cil_insert(log, ticket, lv->lv_item, lv); + } +} + +static void +xlog_cil_free_logvec( + struct xfs_log_vec *log_vector) +{ + struct xfs_log_vec *lv; + + for (lv = log_vector; lv; ) { + struct xfs_log_vec *next = lv->lv_next; + kmem_free(lv->lv_buf); + kmem_free(lv); + lv = next; + } +} + +/* + * Commit a transaction with the given vector to the Committed Item List. + * + * To do this, we need to format the item, pin it in memory if required and + * account for the space used by the transaction. Once we have done that we + * need to release the unused reservation for the transaction, attach the + * transaction to the checkpoint context so we carry the busy extents through + * to checkpoint completion, and then unlock all the items in the transaction. + * + * For more specific information about the order of operations in + * xfs_log_commit_cil() please refer to the comments in + * xfs_trans_commit_iclog(). + * + * Called with the context lock already held in read mode to lock out + * background commit, returns without it held once background commits are + * allowed again. + */ +int +xfs_log_commit_cil( + struct xfs_mount *mp, + struct xfs_trans *tp, + struct xfs_log_vec *log_vector, + xfs_lsn_t *commit_lsn, + int flags) +{ + struct log *log = mp->m_log; + int log_flags = 0; + int push = 0; + + if (flags & XFS_TRANS_RELEASE_LOG_RES) + log_flags = XFS_LOG_REL_PERM_RESERV; + + if (XLOG_FORCED_SHUTDOWN(log)) { + xlog_cil_free_logvec(log_vector); + return XFS_ERROR(EIO); + } + + /* lock out background commit */ + down_read(&log->l_cilp->xc_ctx_lock); + xlog_cil_format_items(log, log_vector, tp->t_ticket, commit_lsn); + + /* check we didn't blow the reservation */ + if (tp->t_ticket->t_curr_res < 0) + xlog_print_tic_res(log->l_mp, tp->t_ticket); + + /* attach the transaction to the CIL if it has any busy extents */ + if (!list_empty(&tp->t_busy)) { + spin_lock(&log->l_cilp->xc_cil_lock); + list_splice_init(&tp->t_busy, + &log->l_cilp->xc_ctx->busy_extents); + spin_unlock(&log->l_cilp->xc_cil_lock); + } + + tp->t_commit_lsn = *commit_lsn; + xfs_log_done(mp, tp->t_ticket, NULL, log_flags); + xfs_trans_unreserve_and_mod_sb(tp); + + /* check for background commit before unlock */ + if (log->l_cilp->xc_ctx->space_used > XLOG_CIL_SPACE_LIMIT(log)) + push = 1; + up_read(&log->l_cilp->xc_ctx_lock); + + /* + * We need to push CIL every so often so we don't cache more than we + * can fit in the log. The limit really is that a checkpoint can't be + * more than half the log (the current checkpoint is not allowed to + * overwrite the previous checkpoint), but commit latency and memory + * usage limit this to a smaller size in most cases. + */ + if (push) + xlog_cil_push(log, 0); + return 0; +} + +/* + * Mark all items committed and clear busy extents. We free the log vector + * chains in a separate pass so that we unpin the log items as quickly as + * possible. + */ +static void +xlog_cil_committed( + void *args, + int abort) +{ + struct xfs_cil_ctx *ctx = args; + struct xfs_log_vec *lv; + int abortflag = abort ? XFS_LI_ABORTED : 0; + struct xfs_busy_extent *busyp, *n; + + /* unpin all the log items */ + for (lv = ctx->lv_chain; lv; lv = lv->lv_next ) { + xfs_trans_item_committed(lv->lv_item, ctx->start_lsn, + abortflag); + } + + list_for_each_entry_safe(busyp, n, &ctx->busy_extents, list) + xfs_alloc_busy_clear(ctx->cil->xc_log->l_mp, busyp); + + spin_lock(&ctx->cil->xc_cil_lock); + list_del(&ctx->committing); + spin_unlock(&ctx->cil->xc_cil_lock); + + xlog_cil_free_logvec(ctx->lv_chain); + kmem_free(ctx); +} + +/* + * Push the Committed Item List to the log. If the push_now flag is not set, + * then it is a background flush and so we can chose to ignore it. + */ +int +xlog_cil_push( + struct log *log, + int push_now) +{ + struct xfs_cil *cil = log->l_cilp; + struct xfs_log_vec *lv; + struct xfs_cil_ctx *ctx; + struct xfs_cil_ctx *new_ctx; + struct xlog_in_core *commit_iclog; + struct xlog_ticket *tic; + int num_lv; + int num_iovecs; + int len; + int error = 0; + struct xfs_trans_header thdr; + struct xfs_log_iovec lhdr; + struct xfs_log_vec lvhdr = { NULL }; + xfs_lsn_t commit_lsn; + + if (!cil) + return 0; + + new_ctx = kmem_zalloc(sizeof(*new_ctx), KM_SLEEP|KM_NOFS); + new_ctx->ticket = xlog_cil_ticket_alloc(log); + + /* lock out transaction commit, but don't block on background push */ + if (!down_write_trylock(&cil->xc_ctx_lock)) { + if (!push_now) + goto out_free_ticket; + down_write(&cil->xc_ctx_lock); + } + ctx = cil->xc_ctx; + + /* check if we've anything to push */ + if (list_empty(&cil->xc_cil)) + goto out_skip; + + /* check for spurious background flush */ + if (!push_now && cil->xc_ctx->space_used < XLOG_CIL_SPACE_LIMIT(log)) + goto out_skip; + + /* + * pull all the log vectors off the items in the CIL, and + * remove the items from the CIL. We don't need the CIL lock + * here because it's only needed on the transaction commit + * side which is currently locked out by the flush lock. + */ + lv = NULL; + num_lv = 0; + num_iovecs = 0; + len = 0; + while (!list_empty(&cil->xc_cil)) { + struct xfs_log_item *item; + int i; + + item = list_first_entry(&cil->xc_cil, + struct xfs_log_item, li_cil); + list_del_init(&item->li_cil); + if (!ctx->lv_chain) + ctx->lv_chain = item->li_lv; + else + lv->lv_next = item->li_lv; + lv = item->li_lv; + item->li_lv = NULL; + + num_lv++; + num_iovecs += lv->lv_niovecs; + for (i = 0; i < lv->lv_niovecs; i++) + len += lv->lv_iovecp[i].i_len; + } + + /* + * initialise the new context and attach it to the CIL. Then attach + * the current context to the CIL committing lsit so it can be found + * during log forces to extract the commit lsn of the sequence that + * needs to be forced. + */ + INIT_LIST_HEAD(&new_ctx->committing); + INIT_LIST_HEAD(&new_ctx->busy_extents); + new_ctx->sequence = ctx->sequence + 1; + new_ctx->cil = cil; + cil->xc_ctx = new_ctx; + + /* + * The switch is now done, so we can drop the context lock and move out + * of a shared context. We can't just go straight to the commit record, + * though - we need to synchronise with previous and future commits so + * that the commit records are correctly ordered in the log to ensure + * that we process items during log IO completion in the correct order. + * + * For example, if we get an EFI in one checkpoint and the EFD in the + * next (e.g. due to log forces), we do not want the checkpoint with + * the EFD to be committed before the checkpoint with the EFI. Hence + * we must strictly order the commit records of the checkpoints so + * that: a) the checkpoint callbacks are attached to the iclogs in the + * correct order; and b) the checkpoints are replayed in correct order + * in log recovery. + * + * Hence we need to add this context to the committing context list so + * that higher sequences will wait for us to write out a commit record + * before they do. + */ + spin_lock(&cil->xc_cil_lock); + list_add(&ctx->committing, &cil->xc_committing); + spin_unlock(&cil->xc_cil_lock); + up_write(&cil->xc_ctx_lock); + + /* + * Build a checkpoint transaction header and write it to the log to + * begin the transaction. We need to account for the space used by the + * transaction header here as it is not accounted for in xlog_write(). + * + * The LSN we need to pass to the log items on transaction commit is + * the LSN reported by the first log vector write. If we use the commit + * record lsn then we can move the tail beyond the grant write head. + */ + tic = ctx->ticket; + thdr.th_magic = XFS_TRANS_HEADER_MAGIC; + thdr.th_type = XFS_TRANS_CHECKPOINT; + thdr.th_tid = tic->t_tid; + thdr.th_num_items = num_iovecs; + lhdr.i_addr = (xfs_caddr_t)&thdr; + lhdr.i_len = sizeof(xfs_trans_header_t); + lhdr.i_type = XLOG_REG_TYPE_TRANSHDR; + tic->t_curr_res -= lhdr.i_len + sizeof(xlog_op_header_t); + + lvhdr.lv_niovecs = 1; + lvhdr.lv_iovecp = &lhdr; + lvhdr.lv_next = ctx->lv_chain; + + error = xlog_write(log, &lvhdr, tic, &ctx->start_lsn, NULL, 0); + if (error) + goto out_abort; + + /* + * now that we've written the checkpoint into the log, strictly + * order the commit records so replay will get them in the right order. + */ +restart: + spin_lock(&cil->xc_cil_lock); + list_for_each_entry(new_ctx, &cil->xc_committing, committing) { + /* + * Higher sequences will wait for this one so skip them. + * Don't wait for own own sequence, either. + */ + if (new_ctx->sequence >= ctx->sequence) + continue; + if (!new_ctx->commit_lsn) { + /* + * It is still being pushed! Wait for the push to + * complete, then start again from the beginning. + */ + sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0); + goto restart; + } + } + spin_unlock(&cil->xc_cil_lock); + + commit_lsn = xfs_log_done(log->l_mp, tic, &commit_iclog, 0); + if (error || commit_lsn == -1) + goto out_abort; + + /* attach all the transactions w/ busy extents to iclog */ + ctx->log_cb.cb_func = xlog_cil_committed; + ctx->log_cb.cb_arg = ctx; + error = xfs_log_notify(log->l_mp, commit_iclog, &ctx->log_cb); + if (error) + goto out_abort; + + /* + * now the checkpoint commit is complete and we've attached the + * callbacks to the iclog we can assign the commit LSN to the context + * and wake up anyone who is waiting for the commit to complete. + */ + spin_lock(&cil->xc_cil_lock); + ctx->commit_lsn = commit_lsn; + sv_broadcast(&cil->xc_commit_wait); + spin_unlock(&cil->xc_cil_lock); + + /* release the hounds! */ + return xfs_log_release_iclog(log->l_mp, commit_iclog); + +out_skip: + up_write(&cil->xc_ctx_lock); +out_free_ticket: + xfs_log_ticket_put(new_ctx->ticket); + kmem_free(new_ctx); + return 0; + +out_abort: + xlog_cil_committed(ctx, XFS_LI_ABORTED); + return XFS_ERROR(EIO); +} + +/* + * Conditionally push the CIL based on the sequence passed in. + * + * We only need to push if we haven't already pushed the sequence + * number given. Hence the only time we will trigger a push here is + * if the push sequence is the same as the current context. + * + * We return the current commit lsn to allow the callers to determine if a + * iclog flush is necessary following this call. + * + * XXX: Initially, just push the CIL unconditionally and return whatever + * commit lsn is there. It'll be empty, so this is broken for now. + */ +xfs_lsn_t +xlog_cil_push_lsn( + struct log *log, + xfs_lsn_t push_seq) +{ + struct xfs_cil *cil = log->l_cilp; + struct xfs_cil_ctx *ctx; + xfs_lsn_t commit_lsn = NULLCOMMITLSN; + +restart: + down_write(&cil->xc_ctx_lock); + ASSERT(push_seq <= cil->xc_ctx->sequence); + + /* check to see if we need to force out the current context */ + if (push_seq == cil->xc_ctx->sequence) { + up_write(&cil->xc_ctx_lock); + xlog_cil_push(log, 1); + goto restart; + } + + /* + * See if we can find a previous sequence still committing. + * We can drop the flush lock as soon as we have the cil lock + * because we are now only comparing contexts protected by + * the cil lock. + * + * We need to wait for all previous sequence commits to complete + * before allowing the force of push_seq to go ahead. Hence block + * on commits for those as well. + */ + spin_lock(&cil->xc_cil_lock); + up_write(&cil->xc_ctx_lock); + list_for_each_entry(ctx, &cil->xc_committing, committing) { + if (ctx->sequence > push_seq) + continue; + if (!ctx->commit_lsn) { + /* + * It is still being pushed! Wait for the push to + * complete, then start again from the beginning. + */ + sv_wait(&cil->xc_commit_wait, 0, &cil->xc_cil_lock, 0); + goto restart; + } + if (ctx->sequence != push_seq) + continue; + /* found it! */ + commit_lsn = ctx->commit_lsn; + } + spin_unlock(&cil->xc_cil_lock); + return commit_lsn; +} + +/* + * Check if the current log item was first committed in this sequence. + * We can't rely on just the log item being in the CIL, we have to check + * the recorded commit sequence number. + * + * Note: for this to be used in a non-racy manner, it has to be called with + * CIL flushing locked out. As a result, it should only be used during the + * transaction commit process when deciding what to format into the item. + */ +bool +xfs_log_item_in_current_chkpt( + struct xfs_log_item *lip) +{ + struct xfs_cil_ctx *ctx; + + if (!(lip->li_mountp->m_flags & XFS_MOUNT_DELAYLOG)) + return false; + if (list_empty(&lip->li_cil)) + return false; + + ctx = lip->li_mountp->m_log->l_cilp->xc_ctx; + + /* + * li_seq is written on the first commit of a log item to record the + * first checkpoint it is written to. Hence if it is different to the + * current sequence, we're in a new checkpoint. + */ + if (XFS_LSN_CMP(lip->li_seq, ctx->sequence) != 0) + return false; + return true; +} diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h index 9cf6951..8c07261 100644 --- a/fs/xfs/xfs_log_priv.h +++ b/fs/xfs/xfs_log_priv.h @@ -152,8 +152,6 @@ static inline uint xlog_get_client_id(__be32 i) #define XLOG_RECOVERY_NEEDED 0x4 /* log was recovered */ #define XLOG_IO_ERROR 0x8 /* log hit an I/O error, and being shutdown */ -typedef __uint32_t xlog_tid_t; - #ifdef __KERNEL__ /* @@ -379,6 +377,99 @@ typedef struct xlog_in_core { } xlog_in_core_t; /* + * The CIL context is used to aggregate per-transaction details as well be + * passed to the iclog for checkpoint post-commit processing. After being + * passed to the iclog, another context needs to be allocated for tracking the + * next set of transactions to be aggregated into a checkpoint. + */ +struct xfs_cil; + +struct xfs_cil_ctx { + struct xfs_cil *cil; + xfs_lsn_t sequence; /* chkpt sequence # */ + xfs_lsn_t start_lsn; /* first LSN of chkpt commit */ + xfs_lsn_t commit_lsn; /* chkpt commit record lsn */ + struct xlog_ticket *ticket; /* chkpt ticket */ + int nvecs; /* number of regions */ + int space_used; /* aggregate size of regions */ + struct list_head busy_extents; /* busy extents in chkpt */ + struct xfs_log_vec *lv_chain; /* logvecs being pushed */ + xfs_log_callback_t log_cb; /* completion callback hook. */ + struct list_head committing; /* ctx committing list */ +}; + +/* + * Committed Item List structure + * + * This structure is used to track log items that have been committed but not + * yet written into the log. It is used only when the delayed logging mount + * option is enabled. + * + * This structure tracks the list of committing checkpoint contexts so + * we can avoid the problem of having to hold out new transactions during a + * flush until we have a the commit record LSN of the checkpoint. We can + * traverse the list of committing contexts in xlog_cil_push_lsn() to find a + * sequence match and extract the commit LSN directly from there. If the + * checkpoint is still in the process of committing, we can block waiting for + * the commit LSN to be determined as well. This should make synchronous + * operations almost as efficient as the old logging methods. + */ +struct xfs_cil { + struct log *xc_log; + struct list_head xc_cil; + spinlock_t xc_cil_lock; + struct xfs_cil_ctx *xc_ctx; + struct rw_semaphore xc_ctx_lock; + struct list_head xc_committing; + sv_t xc_commit_wait; +}; + +/* + * The amount of log space we should the CIL to aggregate is difficult to size. + * Whatever we chose we have to make we can get a reservation for the log space + * effectively, that it is large enough to capture sufficient relogging to + * reduce log buffer IO significantly, but it is not too large for the log or + * induces too much latency when writing out through the iclogs. We track both + * space consumed and the number of vectors in the checkpoint context, so we + * need to decide which to use for limiting. + * + * Every log buffer we write out during a push needs a header reserved, which + * is at least one sector and more for v2 logs. Hence we need a reservation of + * at least 512 bytes per 32k of log space just for the LR headers. That means + * 16KB of reservation per megabyte of delayed logging space we will consume, + * plus various headers. The number of headers will vary based on the num of + * io vectors, so limiting on a specific number of vectors is going to result + * in transactions of varying size. IOWs, it is more consistent to track and + * limit space consumed in the log rather than by the number of objects being + * logged in order to prevent checkpoint ticket overruns. + * + * Further, use of static reservations through the log grant mechanism is + * problematic. It introduces a lot of complexity (e.g. reserve grant vs write + * grant) and a significant deadlock potential because regranting write space + * can block on log pushes. Hence if we have to regrant log space during a log + * push, we can deadlock. + * + * However, we can avoid this by use of a dynamic "reservation stealing" + * technique during transaction commit whereby unused reservation space in the + * transaction ticket is transferred to the CIL ctx commit ticket to cover the + * space needed by the checkpoint transaction. This means that we never need to + * specifically reserve space for the CIL checkpoint transaction, nor do we + * need to regrant space once the checkpoint completes. This also means the + * checkpoint transaction ticket is specific to the checkpoint context, rather + * than the CIL itself. + * + * With dynamic reservations, we can basically make up arbitrary limits for the + * checkpoint size so long as they don't violate any other size rules. Hence + * the initial maximum size for the checkpoint transaction will be set to a + * quarter of the log or 8MB, which ever is smaller. 8MB is an arbitrary limit + * right now based on the latency of writing out a large amount of data through + * the circular iclog buffers. + */ + +#define XLOG_CIL_SPACE_LIMIT(log) \ + (min((log->l_logsize >> 2), (8 * 1024 * 1024))) + +/* * The reservation head lsn is not made up of a cycle number and block number. * Instead, it uses a cycle number and byte number. Logs don't expect to * overflow 31 bits worth of byte offset, so using a byte number will mean @@ -388,6 +479,7 @@ typedef struct log { /* The following fields don't need locking */ struct xfs_mount *l_mp; /* mount point */ struct xfs_ail *l_ailp; /* AIL log is working with */ + struct xfs_cil *l_cilp; /* CIL log is working with */ struct xfs_buf *l_xbuf; /* extra buffer for log * wrapping */ struct xfs_buftarg *l_targ; /* buftarg of log */ @@ -438,14 +530,17 @@ typedef struct log { #define XLOG_FORCED_SHUTDOWN(log) ((log)->l_flags & XLOG_IO_ERROR) - /* common routines */ extern xfs_lsn_t xlog_assign_tail_lsn(struct xfs_mount *mp); extern int xlog_recover(xlog_t *log); extern int xlog_recover_finish(xlog_t *log); extern void xlog_pack_data(xlog_t *log, xlog_in_core_t *iclog, int); -extern kmem_zone_t *xfs_log_ticket_zone; +extern kmem_zone_t *xfs_log_ticket_zone; +struct xlog_ticket *xlog_ticket_alloc(struct log *log, int unit_bytes, + int count, char client, uint xflags, + int alloc_flags); + static inline void xlog_write_adv_cnt(void **ptr, int *len, int *off, size_t bytes) @@ -455,6 +550,21 @@ xlog_write_adv_cnt(void **ptr, int *len, int *off, size_t bytes) *off += bytes; } +void xlog_print_tic_res(struct xfs_mount *mp, struct xlog_ticket *ticket); +int xlog_write(struct log *log, struct xfs_log_vec *log_vector, + struct xlog_ticket *tic, xfs_lsn_t *start_lsn, + xlog_in_core_t **commit_iclog, uint flags); + +/* + * Committed Item List interfaces + */ +int xlog_cil_init(struct log *log); +void xlog_cil_init_post_recovery(struct log *log); +void xlog_cil_destroy(struct log *log); + +int xlog_cil_push(struct log *log, int push_now); +xfs_lsn_t xlog_cil_push_lsn(struct log *log, xfs_lsn_t push_sequence); + /* * Unmount record type is used as a pseudo transaction type for the ticket. * It's value must be outside the range of XFS_TRANS_* values. diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c index 0de08e3..14a69ae 100644 --- a/fs/xfs/xfs_log_recover.c +++ b/fs/xfs/xfs_log_recover.c @@ -1576,7 +1576,7 @@ xlog_recover_reorder_trans( switch (ITEM_TYPE(item)) { case XFS_LI_BUF: - if (!(buf_f->blf_flags & XFS_BLI_CANCEL)) { + if (!(buf_f->blf_flags & XFS_BLF_CANCEL)) { trace_xfs_log_recover_item_reorder_head(log, trans, item, pass); list_move(&item->ri_list, &trans->r_itemq); @@ -1638,7 +1638,7 @@ xlog_recover_do_buffer_pass1( /* * If this isn't a cancel buffer item, then just return. */ - if (!(flags & XFS_BLI_CANCEL)) { + if (!(flags & XFS_BLF_CANCEL)) { trace_xfs_log_recover_buf_not_cancel(log, buf_f); return; } @@ -1696,7 +1696,7 @@ xlog_recover_do_buffer_pass1( * Check to see whether the buffer being recovered has a corresponding * entry in the buffer cancel record table. If it does then return 1 * so that it will be cancelled, otherwise return 0. If the buffer is - * actually a buffer cancel item (XFS_BLI_CANCEL is set), then decrement + * actually a buffer cancel item (XFS_BLF_CANCEL is set), then decrement * the refcount on the entry in the table and remove it from the table * if this is the last reference. * @@ -1721,7 +1721,7 @@ xlog_check_buffer_cancelled( * There is nothing in the table built in pass one, * so this buffer must not be cancelled. */ - ASSERT(!(flags & XFS_BLI_CANCEL)); + ASSERT(!(flags & XFS_BLF_CANCEL)); return 0; } @@ -1733,7 +1733,7 @@ xlog_check_buffer_cancelled( * There is no corresponding entry in the table built * in pass one, so this buffer has not been cancelled. */ - ASSERT(!(flags & XFS_BLI_CANCEL)); + ASSERT(!(flags & XFS_BLF_CANCEL)); return 0; } @@ -1752,7 +1752,7 @@ xlog_check_buffer_cancelled( * one in the table and remove it if this is the * last reference. */ - if (flags & XFS_BLI_CANCEL) { + if (flags & XFS_BLF_CANCEL) { bcp->bc_refcount--; if (bcp->bc_refcount == 0) { if (prevp == NULL) { @@ -1772,7 +1772,7 @@ xlog_check_buffer_cancelled( * We didn't find a corresponding entry in the table, so * return 0 so that the buffer is NOT cancelled. */ - ASSERT(!(flags & XFS_BLI_CANCEL)); + ASSERT(!(flags & XFS_BLF_CANCEL)); return 0; } @@ -1874,8 +1874,8 @@ xlog_recover_do_inode_buffer( nbits = xfs_contig_bits(data_map, map_size, bit); ASSERT(nbits > 0); - reg_buf_offset = bit << XFS_BLI_SHIFT; - reg_buf_bytes = nbits << XFS_BLI_SHIFT; + reg_buf_offset = bit << XFS_BLF_SHIFT; + reg_buf_bytes = nbits << XFS_BLF_SHIFT; item_index++; } @@ -1889,7 +1889,7 @@ xlog_recover_do_inode_buffer( } ASSERT(item->ri_buf[item_index].i_addr != NULL); - ASSERT((item->ri_buf[item_index].i_len % XFS_BLI_CHUNK) == 0); + ASSERT((item->ri_buf[item_index].i_len % XFS_BLF_CHUNK) == 0); ASSERT((reg_buf_offset + reg_buf_bytes) <= XFS_BUF_COUNT(bp)); /* @@ -1955,9 +1955,9 @@ xlog_recover_do_reg_buffer( nbits = xfs_contig_bits(data_map, map_size, bit); ASSERT(nbits > 0); ASSERT(item->ri_buf[i].i_addr != NULL); - ASSERT(item->ri_buf[i].i_len % XFS_BLI_CHUNK == 0); + ASSERT(item->ri_buf[i].i_len % XFS_BLF_CHUNK == 0); ASSERT(XFS_BUF_COUNT(bp) >= - ((uint)bit << XFS_BLI_SHIFT)+(nbits<<XFS_BLI_SHIFT)); + ((uint)bit << XFS_BLF_SHIFT)+(nbits<<XFS_BLF_SHIFT)); /* * Do a sanity check if this is a dquot buffer. Just checking @@ -1966,7 +1966,7 @@ xlog_recover_do_reg_buffer( */ error = 0; if (buf_f->blf_flags & - (XFS_BLI_UDQUOT_BUF|XFS_BLI_PDQUOT_BUF|XFS_BLI_GDQUOT_BUF)) { + (XFS_BLF_UDQUOT_BUF|XFS_BLF_PDQUOT_BUF|XFS_BLF_GDQUOT_BUF)) { if (item->ri_buf[i].i_addr == NULL) { cmn_err(CE_ALERT, "XFS: NULL dquot in %s.", __func__); @@ -1987,9 +1987,9 @@ xlog_recover_do_reg_buffer( } memcpy(xfs_buf_offset(bp, - (uint)bit << XFS_BLI_SHIFT), /* dest */ + (uint)bit << XFS_BLF_SHIFT), /* dest */ item->ri_buf[i].i_addr, /* source */ - nbits<<XFS_BLI_SHIFT); /* length */ + nbits<<XFS_BLF_SHIFT); /* length */ next: i++; bit += nbits; @@ -2148,11 +2148,11 @@ xlog_recover_do_dquot_buffer( } type = 0; - if (buf_f->blf_flags & XFS_BLI_UDQUOT_BUF) + if (buf_f->blf_flags & XFS_BLF_UDQUOT_BUF) type |= XFS_DQ_USER; - if (buf_f->blf_flags & XFS_BLI_PDQUOT_BUF) + if (buf_f->blf_flags & XFS_BLF_PDQUOT_BUF) type |= XFS_DQ_PROJ; - if (buf_f->blf_flags & XFS_BLI_GDQUOT_BUF) + if (buf_f->blf_flags & XFS_BLF_GDQUOT_BUF) type |= XFS_DQ_GROUP; /* * This type of quotas was turned off, so ignore this buffer @@ -2173,7 +2173,7 @@ xlog_recover_do_dquot_buffer( * here which overlaps that may be stale. * * When meta-data buffers are freed at run time we log a buffer item - * with the XFS_BLI_CANCEL bit set to indicate that previous copies + * with the XFS_BLF_CANCEL bit set to indicate that previous copies * of the buffer in the log should not be replayed at recovery time. * This is so that if the blocks covered by the buffer are reused for * file data before we crash we don't end up replaying old, freed @@ -2207,7 +2207,7 @@ xlog_recover_do_buffer_trans( if (pass == XLOG_RECOVER_PASS1) { /* * In this pass we're only looking for buf items - * with the XFS_BLI_CANCEL bit set. + * with the XFS_BLF_CANCEL bit set. */ xlog_recover_do_buffer_pass1(log, buf_f); return 0; @@ -2244,7 +2244,7 @@ xlog_recover_do_buffer_trans( mp = log->l_mp; buf_flags = XBF_LOCK; - if (!(flags & XFS_BLI_INODE_BUF)) + if (!(flags & XFS_BLF_INODE_BUF)) buf_flags |= XBF_MAPPED; bp = xfs_buf_read(mp->m_ddev_targp, blkno, len, buf_flags); @@ -2257,10 +2257,10 @@ xlog_recover_do_buffer_trans( } error = 0; - if (flags & XFS_BLI_INODE_BUF) { + if (flags & XFS_BLF_INODE_BUF) { error = xlog_recover_do_inode_buffer(mp, item, bp, buf_f); } else if (flags & - (XFS_BLI_UDQUOT_BUF|XFS_BLI_PDQUOT_BUF|XFS_BLI_GDQUOT_BUF)) { + (XFS_BLF_UDQUOT_BUF|XFS_BLF_PDQUOT_BUF|XFS_BLF_GDQUOT_BUF)) { xlog_recover_do_dquot_buffer(mp, log, item, bp, buf_f); } else { xlog_recover_do_reg_buffer(mp, item, bp, buf_f); diff --git a/fs/xfs/xfs_log_recover.h b/fs/xfs/xfs_log_recover.h index 75d7492..1c55ccb 100644 --- a/fs/xfs/xfs_log_recover.h +++ b/fs/xfs/xfs_log_recover.h @@ -28,7 +28,7 @@ #define XLOG_RHASH(tid) \ ((((__uint32_t)tid)>>XLOG_RHASH_SHIFT) & (XLOG_RHASH_SIZE-1)) -#define XLOG_MAX_REGIONS_IN_ITEM (XFS_MAX_BLOCKSIZE / XFS_BLI_CHUNK / 2 + 1) +#define XLOG_MAX_REGIONS_IN_ITEM (XFS_MAX_BLOCKSIZE / XFS_BLF_CHUNK / 2 + 1) /* diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h index 9ff48a16..1d2c7ee 100644 --- a/fs/xfs/xfs_mount.h +++ b/fs/xfs/xfs_mount.h @@ -268,6 +268,7 @@ typedef struct xfs_mount { #define XFS_MOUNT_WSYNC (1ULL << 0) /* for nfs - all metadata ops must be synchronous except for space allocations */ +#define XFS_MOUNT_DELAYLOG (1ULL << 1) /* delayed logging is enabled */ #define XFS_MOUNT_DMAPI (1ULL << 2) /* dmapi is enabled */ #define XFS_MOUNT_WAS_CLEAN (1ULL << 3) #define XFS_MOUNT_FS_SHUTDOWN (1ULL << 4) /* atomic stop of all filesystem diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index be578ec..ce558ef 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -44,6 +44,7 @@ #include "xfs_trans_priv.h" #include "xfs_trans_space.h" #include "xfs_inode_item.h" +#include "xfs_trace.h" kmem_zone_t *xfs_trans_zone; @@ -243,9 +244,8 @@ _xfs_trans_alloc( tp->t_type = type; tp->t_mountp = mp; tp->t_items_free = XFS_LIC_NUM_SLOTS; - tp->t_busy_free = XFS_LBC_NUM_SLOTS; xfs_lic_init(&(tp->t_items)); - XFS_LBC_INIT(&(tp->t_busy)); + INIT_LIST_HEAD(&tp->t_busy); return tp; } @@ -255,8 +255,13 @@ _xfs_trans_alloc( */ STATIC void xfs_trans_free( - xfs_trans_t *tp) + struct xfs_trans *tp) { + struct xfs_busy_extent *busyp, *n; + + list_for_each_entry_safe(busyp, n, &tp->t_busy, list) + xfs_alloc_busy_clear(tp->t_mountp, busyp); + atomic_dec(&tp->t_mountp->m_active_trans); xfs_trans_free_dqinfo(tp); kmem_zone_free(xfs_trans_zone, tp); @@ -285,9 +290,8 @@ xfs_trans_dup( ntp->t_type = tp->t_type; ntp->t_mountp = tp->t_mountp; ntp->t_items_free = XFS_LIC_NUM_SLOTS; - ntp->t_busy_free = XFS_LBC_NUM_SLOTS; xfs_lic_init(&(ntp->t_items)); - XFS_LBC_INIT(&(ntp->t_busy)); + INIT_LIST_HEAD(&ntp->t_busy); ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES); ASSERT(tp->t_ticket != NULL); @@ -423,7 +427,6 @@ undo_blocks: return error; } - /* * Record the indicated change to the given field for application * to the file system's superblock when the transaction commits. @@ -652,7 +655,7 @@ xfs_trans_apply_sb_deltas( * XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we * still need to update the incore superblock with the changes. */ -STATIC void +void xfs_trans_unreserve_and_mod_sb( xfs_trans_t *tp) { @@ -880,7 +883,7 @@ xfs_trans_fill_vecs( * they could be immediately flushed and we'd have to race with the flusher * trying to pull the item from the AIL as we add it. */ -static void +void xfs_trans_item_committed( struct xfs_log_item *lip, xfs_lsn_t commit_lsn, @@ -930,26 +933,6 @@ xfs_trans_item_committed( IOP_UNPIN(lip); } -/* Clear all the per-AG busy list items listed in this transaction */ -static void -xfs_trans_clear_busy_extents( - struct xfs_trans *tp) -{ - xfs_log_busy_chunk_t *lbcp; - xfs_log_busy_slot_t *lbsp; - int i; - - for (lbcp = &tp->t_busy; lbcp != NULL; lbcp = lbcp->lbc_next) { - i = 0; - for (lbsp = lbcp->lbc_busy; i < lbcp->lbc_unused; i++, lbsp++) { - if (XFS_LBC_ISFREE(lbcp, i)) - continue; - xfs_alloc_clear_busy(tp, lbsp->lbc_ag, lbsp->lbc_idx); - } - } - xfs_trans_free_busy(tp); -} - /* * This is typically called by the LM when a transaction has been fully * committed to disk. It needs to unpin the items which have @@ -984,7 +967,6 @@ xfs_trans_committed( kmem_free(licp); } - xfs_trans_clear_busy_extents(tp); xfs_trans_free(tp); } @@ -1012,8 +994,7 @@ xfs_trans_uncommit( xfs_trans_unreserve_and_mod_sb(tp); xfs_trans_unreserve_and_mod_dquots(tp); - xfs_trans_free_items(tp, flags); - xfs_trans_free_busy(tp); + xfs_trans_free_items(tp, NULLCOMMITLSN, flags); xfs_trans_free(tp); } @@ -1075,6 +1056,8 @@ xfs_trans_commit_iclog( *commit_lsn = xfs_log_done(mp, tp->t_ticket, &commit_iclog, log_flags); tp->t_commit_lsn = *commit_lsn; + trace_xfs_trans_commit_lsn(tp); + if (nvec > XFS_TRANS_LOGVEC_COUNT) kmem_free(log_vector); @@ -1161,6 +1144,93 @@ xfs_trans_commit_iclog( return xfs_log_release_iclog(mp, commit_iclog); } +/* + * Walk the log items and allocate log vector structures for + * each item large enough to fit all the vectors they require. + * Note that this format differs from the old log vector format in + * that there is no transaction header in these log vectors. + */ +STATIC struct xfs_log_vec * +xfs_trans_alloc_log_vecs( + xfs_trans_t *tp) +{ + xfs_log_item_desc_t *lidp; + struct xfs_log_vec *lv = NULL; + struct xfs_log_vec *ret_lv = NULL; + + lidp = xfs_trans_first_item(tp); + + /* Bail out if we didn't find a log item. */ + if (!lidp) { + ASSERT(0); + return NULL; + } + + while (lidp != NULL) { + struct xfs_log_vec *new_lv; + + /* Skip items which aren't dirty in this transaction. */ + if (!(lidp->lid_flags & XFS_LID_DIRTY)) { + lidp = xfs_trans_next_item(tp, lidp); + continue; + } + + /* Skip items that do not have any vectors for writing */ + lidp->lid_size = IOP_SIZE(lidp->lid_item); + if (!lidp->lid_size) { + lidp = xfs_trans_next_item(tp, lidp); + continue; + } + + new_lv = kmem_zalloc(sizeof(*new_lv) + + lidp->lid_size * sizeof(struct xfs_log_iovec), + KM_SLEEP); + + /* The allocated iovec region lies beyond the log vector. */ + new_lv->lv_iovecp = (struct xfs_log_iovec *)&new_lv[1]; + new_lv->lv_niovecs = lidp->lid_size; + new_lv->lv_item = lidp->lid_item; + if (!ret_lv) + ret_lv = new_lv; + else + lv->lv_next = new_lv; + lv = new_lv; + lidp = xfs_trans_next_item(tp, lidp); + } + + return ret_lv; +} + +static int +xfs_trans_commit_cil( + struct xfs_mount *mp, + struct xfs_trans *tp, + xfs_lsn_t *commit_lsn, + int flags) +{ + struct xfs_log_vec *log_vector; + int error; + + /* + * Get each log item to allocate a vector structure for + * the log item to to pass to the log write code. The + * CIL commit code will format the vector and save it away. + */ + log_vector = xfs_trans_alloc_log_vecs(tp); + if (!log_vector) + return ENOMEM; + + error = xfs_log_commit_cil(mp, tp, log_vector, commit_lsn, flags); + if (error) + return error; + + current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); + + /* xfs_trans_free_items() unlocks them first */ + xfs_trans_free_items(tp, *commit_lsn, 0); + xfs_trans_free(tp); + return 0; +} /* * xfs_trans_commit @@ -1221,7 +1291,11 @@ _xfs_trans_commit( xfs_trans_apply_sb_deltas(tp); xfs_trans_apply_dquot_deltas(tp); - error = xfs_trans_commit_iclog(mp, tp, &commit_lsn, flags); + if (mp->m_flags & XFS_MOUNT_DELAYLOG) + error = xfs_trans_commit_cil(mp, tp, &commit_lsn, flags); + else + error = xfs_trans_commit_iclog(mp, tp, &commit_lsn, flags); + if (error == ENOMEM) { xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR); error = XFS_ERROR(EIO); @@ -1259,8 +1333,7 @@ out_unreserve: error = XFS_ERROR(EIO); } current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); - xfs_trans_free_items(tp, error ? XFS_TRANS_ABORT : 0); - xfs_trans_free_busy(tp); + xfs_trans_free_items(tp, NULLCOMMITLSN, error ? XFS_TRANS_ABORT : 0); xfs_trans_free(tp); XFS_STATS_INC(xs_trans_empty); @@ -1338,8 +1411,7 @@ xfs_trans_cancel( /* mark this thread as no longer being in a transaction */ current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); - xfs_trans_free_items(tp, flags); - xfs_trans_free_busy(tp); + xfs_trans_free_items(tp, NULLCOMMITLSN, flags); xfs_trans_free(tp); } diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h index c62beee..8c69e78 100644 --- a/fs/xfs/xfs_trans.h +++ b/fs/xfs/xfs_trans.h @@ -106,7 +106,8 @@ typedef struct xfs_trans_header { #define XFS_TRANS_GROWFSRT_FREE 39 #define XFS_TRANS_SWAPEXT 40 #define XFS_TRANS_SB_COUNT 41 -#define XFS_TRANS_TYPE_MAX 41 +#define XFS_TRANS_CHECKPOINT 42 +#define XFS_TRANS_TYPE_MAX 42 /* new transaction types need to be reflected in xfs_logprint(8) */ #define XFS_TRANS_TYPES \ @@ -148,6 +149,7 @@ typedef struct xfs_trans_header { { XFS_TRANS_GROWFSRT_FREE, "GROWFSRT_FREE" }, \ { XFS_TRANS_SWAPEXT, "SWAPEXT" }, \ { XFS_TRANS_SB_COUNT, "SB_COUNT" }, \ + { XFS_TRANS_CHECKPOINT, "CHECKPOINT" }, \ { XFS_TRANS_DUMMY1, "DUMMY1" }, \ { XFS_TRANS_DUMMY2, "DUMMY2" }, \ { XLOG_UNMOUNT_REC_TYPE, "UNMOUNT" } @@ -813,6 +815,7 @@ struct xfs_log_item_desc; struct xfs_mount; struct xfs_trans; struct xfs_dquot_acct; +struct xfs_busy_extent; typedef struct xfs_log_item { struct list_head li_ail; /* AIL pointers */ @@ -828,6 +831,11 @@ typedef struct xfs_log_item { /* buffer item iodone */ /* callback func */ struct xfs_item_ops *li_ops; /* function list */ + + /* delayed logging */ + struct list_head li_cil; /* CIL pointers */ + struct xfs_log_vec *li_lv; /* active log vector */ + xfs_lsn_t li_seq; /* CIL commit seq */ } xfs_log_item_t; #define XFS_LI_IN_AIL 0x1 @@ -872,34 +880,6 @@ typedef struct xfs_item_ops { #define XFS_ITEM_PUSHBUF 3 /* - * This structure is used to maintain a list of block ranges that have been - * freed in the transaction. The ranges are listed in the perag[] busy list - * between when they're freed and the transaction is committed to disk. - */ - -typedef struct xfs_log_busy_slot { - xfs_agnumber_t lbc_ag; - ushort lbc_idx; /* index in perag.busy[] */ -} xfs_log_busy_slot_t; - -#define XFS_LBC_NUM_SLOTS 31 -typedef struct xfs_log_busy_chunk { - struct xfs_log_busy_chunk *lbc_next; - uint lbc_free; /* free slots bitmask */ - ushort lbc_unused; /* first unused */ - xfs_log_busy_slot_t lbc_busy[XFS_LBC_NUM_SLOTS]; -} xfs_log_busy_chunk_t; - -#define XFS_LBC_MAX_SLOT (XFS_LBC_NUM_SLOTS - 1) -#define XFS_LBC_FREEMASK ((1U << XFS_LBC_NUM_SLOTS) - 1) - -#define XFS_LBC_INIT(cp) ((cp)->lbc_free = XFS_LBC_FREEMASK) -#define XFS_LBC_CLAIM(cp, slot) ((cp)->lbc_free &= ~(1 << (slot))) -#define XFS_LBC_SLOT(cp, slot) (&((cp)->lbc_busy[(slot)])) -#define XFS_LBC_VACANCY(cp) (((cp)->lbc_free) & XFS_LBC_FREEMASK) -#define XFS_LBC_ISFREE(cp, slot) ((cp)->lbc_free & (1 << (slot))) - -/* * This is the type of function which can be given to xfs_trans_callback() * to be called upon the transaction's commit to disk. */ @@ -950,8 +930,7 @@ typedef struct xfs_trans { unsigned int t_items_free; /* log item descs free */ xfs_log_item_chunk_t t_items; /* first log item desc chunk */ xfs_trans_header_t t_header; /* header for in-log trans */ - unsigned int t_busy_free; /* busy descs free */ - xfs_log_busy_chunk_t t_busy; /* busy/async free blocks */ + struct list_head t_busy; /* list of busy extents */ unsigned long t_pflags; /* saved process flags state */ } xfs_trans_t; @@ -1025,9 +1004,6 @@ int _xfs_trans_commit(xfs_trans_t *, void xfs_trans_cancel(xfs_trans_t *, int); int xfs_trans_ail_init(struct xfs_mount *); void xfs_trans_ail_destroy(struct xfs_mount *); -xfs_log_busy_slot_t *xfs_trans_add_busy(xfs_trans_t *tp, - xfs_agnumber_t ag, - xfs_extlen_t idx); extern kmem_zone_t *xfs_trans_zone; diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c index 9cd8090..63d81a2 100644 --- a/fs/xfs/xfs_trans_buf.c +++ b/fs/xfs/xfs_trans_buf.c @@ -114,7 +114,7 @@ _xfs_trans_bjoin( xfs_buf_item_init(bp, tp->t_mountp); bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *); ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); - ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_CANCEL)); + ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL)); ASSERT(!(bip->bli_flags & XFS_BLI_LOGGED)); if (reset_recur) bip->bli_recur = 0; @@ -511,7 +511,7 @@ xfs_trans_brelse(xfs_trans_t *tp, bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *); ASSERT(bip->bli_item.li_type == XFS_LI_BUF); ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); - ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_CANCEL)); + ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL)); ASSERT(atomic_read(&bip->bli_refcount) > 0); /* @@ -619,7 +619,7 @@ xfs_trans_bhold(xfs_trans_t *tp, bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *); ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); - ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_CANCEL)); + ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL)); ASSERT(atomic_read(&bip->bli_refcount) > 0); bip->bli_flags |= XFS_BLI_HOLD; trace_xfs_trans_bhold(bip); @@ -641,7 +641,7 @@ xfs_trans_bhold_release(xfs_trans_t *tp, bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *); ASSERT(!(bip->bli_flags & XFS_BLI_STALE)); - ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_CANCEL)); + ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_CANCEL)); ASSERT(atomic_read(&bip->bli_refcount) > 0); ASSERT(bip->bli_flags & XFS_BLI_HOLD); bip->bli_flags &= ~XFS_BLI_HOLD; @@ -704,7 +704,7 @@ xfs_trans_log_buf(xfs_trans_t *tp, bip->bli_flags &= ~XFS_BLI_STALE; ASSERT(XFS_BUF_ISSTALE(bp)); XFS_BUF_UNSTALE(bp); - bip->bli_format.blf_flags &= ~XFS_BLI_CANCEL; + bip->bli_format.blf_flags &= ~XFS_BLF_CANCEL; } lidp = xfs_trans_find_item(tp, (xfs_log_item_t*)bip); @@ -762,8 +762,8 @@ xfs_trans_binval( ASSERT(!(XFS_BUF_ISDELAYWRITE(bp))); ASSERT(XFS_BUF_ISSTALE(bp)); ASSERT(!(bip->bli_flags & (XFS_BLI_LOGGED | XFS_BLI_DIRTY))); - ASSERT(!(bip->bli_format.blf_flags & XFS_BLI_INODE_BUF)); - ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL); + ASSERT(!(bip->bli_format.blf_flags & XFS_BLF_INODE_BUF)); + ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL); ASSERT(lidp->lid_flags & XFS_LID_DIRTY); ASSERT(tp->t_flags & XFS_TRANS_DIRTY); return; @@ -774,7 +774,7 @@ xfs_trans_binval( * in the buf log item. The STALE flag will be used in * xfs_buf_item_unpin() to determine if it should clean up * when the last reference to the buf item is given up. - * We set the XFS_BLI_CANCEL flag in the buf log format structure + * We set the XFS_BLF_CANCEL flag in the buf log format structure * and log the buf item. This will be used at recovery time * to determine that copies of the buffer in the log before * this should not be replayed. @@ -792,9 +792,9 @@ xfs_trans_binval( XFS_BUF_UNDELAYWRITE(bp); XFS_BUF_STALE(bp); bip->bli_flags |= XFS_BLI_STALE; - bip->bli_flags &= ~(XFS_BLI_LOGGED | XFS_BLI_DIRTY); - bip->bli_format.blf_flags &= ~XFS_BLI_INODE_BUF; - bip->bli_format.blf_flags |= XFS_BLI_CANCEL; + bip->bli_flags &= ~(XFS_BLI_INODE_BUF | XFS_BLI_LOGGED | XFS_BLI_DIRTY); + bip->bli_format.blf_flags &= ~XFS_BLF_INODE_BUF; + bip->bli_format.blf_flags |= XFS_BLF_CANCEL; memset((char *)(bip->bli_format.blf_data_map), 0, (bip->bli_format.blf_map_size * sizeof(uint))); lidp->lid_flags |= XFS_LID_DIRTY; @@ -802,16 +802,16 @@ xfs_trans_binval( } /* - * This call is used to indicate that the buffer contains on-disk - * inodes which must be handled specially during recovery. They - * require special handling because only the di_next_unlinked from - * the inodes in the buffer should be recovered. The rest of the - * data in the buffer is logged via the inodes themselves. + * This call is used to indicate that the buffer contains on-disk inodes which + * must be handled specially during recovery. They require special handling + * because only the di_next_unlinked from the inodes in the buffer should be + * recovered. The rest of the data in the buffer is logged via the inodes + * themselves. * - * All we do is set the XFS_BLI_INODE_BUF flag in the buffer's log - * format structure so that we'll know what to do at recovery time. + * All we do is set the XFS_BLI_INODE_BUF flag in the items flags so it can be + * transferred to the buffer's log format structure so that we'll know what to + * do at recovery time. */ -/* ARGSUSED */ void xfs_trans_inode_buf( xfs_trans_t *tp, @@ -826,7 +826,7 @@ xfs_trans_inode_buf( bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *); ASSERT(atomic_read(&bip->bli_refcount) > 0); - bip->bli_format.blf_flags |= XFS_BLI_INODE_BUF; + bip->bli_flags |= XFS_BLI_INODE_BUF; } /* @@ -908,9 +908,9 @@ xfs_trans_dquot_buf( ASSERT(XFS_BUF_ISBUSY(bp)); ASSERT(XFS_BUF_FSPRIVATE2(bp, xfs_trans_t *) == tp); ASSERT(XFS_BUF_FSPRIVATE(bp, void *) != NULL); - ASSERT(type == XFS_BLI_UDQUOT_BUF || - type == XFS_BLI_PDQUOT_BUF || - type == XFS_BLI_GDQUOT_BUF); + ASSERT(type == XFS_BLF_UDQUOT_BUF || + type == XFS_BLF_PDQUOT_BUF || + type == XFS_BLF_GDQUOT_BUF); bip = XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *); ASSERT(atomic_read(&bip->bli_refcount) > 0); diff --git a/fs/xfs/xfs_trans_item.c b/fs/xfs/xfs_trans_item.c index eb3fc57..f11d37d 100644 --- a/fs/xfs/xfs_trans_item.c +++ b/fs/xfs/xfs_trans_item.c @@ -299,6 +299,7 @@ xfs_trans_next_item(xfs_trans_t *tp, xfs_log_item_desc_t *lidp) void xfs_trans_free_items( xfs_trans_t *tp, + xfs_lsn_t commit_lsn, int flags) { xfs_log_item_chunk_t *licp; @@ -311,7 +312,7 @@ xfs_trans_free_items( * Special case the embedded chunk so we don't free it below. */ if (!xfs_lic_are_all_free(licp)) { - (void) xfs_trans_unlock_chunk(licp, 1, abort, NULLCOMMITLSN); + (void) xfs_trans_unlock_chunk(licp, 1, abort, commit_lsn); xfs_lic_all_free(licp); licp->lic_unused = 0; } @@ -322,7 +323,7 @@ xfs_trans_free_items( */ while (licp != NULL) { ASSERT(!xfs_lic_are_all_free(licp)); - (void) xfs_trans_unlock_chunk(licp, 1, abort, NULLCOMMITLSN); + (void) xfs_trans_unlock_chunk(licp, 1, abort, commit_lsn); next_licp = licp->lic_next; kmem_free(licp); licp = next_licp; @@ -438,112 +439,3 @@ xfs_trans_unlock_chunk( return freed; } - - -/* - * This is called to add the given busy item to the transaction's - * list of busy items. It must find a free busy item descriptor - * or allocate a new one and add the item to that descriptor. - * The function returns a pointer to busy descriptor used to point - * to the new busy entry. The log busy entry will now point to its new - * descriptor with its ???? field. - */ -xfs_log_busy_slot_t * -xfs_trans_add_busy(xfs_trans_t *tp, xfs_agnumber_t ag, xfs_extlen_t idx) -{ - xfs_log_busy_chunk_t *lbcp; - xfs_log_busy_slot_t *lbsp; - int i=0; - - /* - * If there are no free descriptors, allocate a new chunk - * of them and put it at the front of the chunk list. - */ - if (tp->t_busy_free == 0) { - lbcp = (xfs_log_busy_chunk_t*) - kmem_alloc(sizeof(xfs_log_busy_chunk_t), KM_SLEEP); - ASSERT(lbcp != NULL); - /* - * Initialize the chunk, and then - * claim the first slot in the newly allocated chunk. - */ - XFS_LBC_INIT(lbcp); - XFS_LBC_CLAIM(lbcp, 0); - lbcp->lbc_unused = 1; - lbsp = XFS_LBC_SLOT(lbcp, 0); - - /* - * Link in the new chunk and update the free count. - */ - lbcp->lbc_next = tp->t_busy.lbc_next; - tp->t_busy.lbc_next = lbcp; - tp->t_busy_free = XFS_LIC_NUM_SLOTS - 1; - - /* - * Initialize the descriptor and the generic portion - * of the log item. - * - * Point the new slot at this item and return it. - * Also point the log item at its currently active - * descriptor and set the item's mount pointer. - */ - lbsp->lbc_ag = ag; - lbsp->lbc_idx = idx; - return lbsp; - } - - /* - * Find the free descriptor. It is somewhere in the chunklist - * of descriptors. - */ - lbcp = &tp->t_busy; - while (lbcp != NULL) { - if (XFS_LBC_VACANCY(lbcp)) { - if (lbcp->lbc_unused <= XFS_LBC_MAX_SLOT) { - i = lbcp->lbc_unused; - break; - } else { - /* out-of-order vacancy */ - cmn_err(CE_DEBUG, "OOO vacancy lbcp 0x%p\n", lbcp); - ASSERT(0); - } - } - lbcp = lbcp->lbc_next; - } - ASSERT(lbcp != NULL); - /* - * If we find a free descriptor, claim it, - * initialize it, and return it. - */ - XFS_LBC_CLAIM(lbcp, i); - if (lbcp->lbc_unused <= i) { - lbcp->lbc_unused = i + 1; - } - lbsp = XFS_LBC_SLOT(lbcp, i); - tp->t_busy_free--; - lbsp->lbc_ag = ag; - lbsp->lbc_idx = idx; - return lbsp; -} - - -/* - * xfs_trans_free_busy - * Free all of the busy lists from a transaction - */ -void -xfs_trans_free_busy(xfs_trans_t *tp) -{ - xfs_log_busy_chunk_t *lbcp; - xfs_log_busy_chunk_t *lbcq; - - lbcp = tp->t_busy.lbc_next; - while (lbcp != NULL) { - lbcq = lbcp->lbc_next; - kmem_free(lbcp); - lbcp = lbcq; - } - - XFS_LBC_INIT(&tp->t_busy); - tp->t_busy.lbc_unused = 0; -} diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h index 73e2ad3..c6e4f2c8 100644 --- a/fs/xfs/xfs_trans_priv.h +++ b/fs/xfs/xfs_trans_priv.h @@ -35,13 +35,14 @@ struct xfs_log_item_desc *xfs_trans_find_item(struct xfs_trans *, struct xfs_log_item_desc *xfs_trans_first_item(struct xfs_trans *); struct xfs_log_item_desc *xfs_trans_next_item(struct xfs_trans *, struct xfs_log_item_desc *); -void xfs_trans_free_items(struct xfs_trans *, int); -void xfs_trans_unlock_items(struct xfs_trans *, - xfs_lsn_t); -void xfs_trans_free_busy(xfs_trans_t *tp); -xfs_log_busy_slot_t *xfs_trans_add_busy(xfs_trans_t *tp, - xfs_agnumber_t ag, - xfs_extlen_t idx); + +void xfs_trans_unlock_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn); +void xfs_trans_free_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn, + int flags); + +void xfs_trans_item_committed(struct xfs_log_item *lip, + xfs_lsn_t commit_lsn, int aborted); +void xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp); /* * AIL traversal cursor. diff --git a/fs/xfs/xfs_types.h b/fs/xfs/xfs_types.h index b099045..3207752 100644 --- a/fs/xfs/xfs_types.h +++ b/fs/xfs/xfs_types.h @@ -75,6 +75,8 @@ typedef __uint32_t xfs_dahash_t; /* dir/attr hash value */ typedef __uint16_t xfs_prid_t; /* prid_t truncated to 16bits in XFS */ +typedef __uint32_t xlog_tid_t; /* transaction ID type */ + /* * These types are 64 bits on disk but are either 32 or 64 bits in memory. * Disk based types: |