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2010-07-15ocfs2: Don't duplicate pages past i_size during CoW.Tao Ma
During CoW, the pages after i_size don't contain valid data, so there's no need to read and duplicate them. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-07-08ocfs2: Zero the tail cluster when extending past i_size.Joel Becker
ocfs2's allocation unit is the cluster. This can be larger than a block or even a memory page. This means that a file may have many blocks in its last extent that are beyond the block containing i_size. There also may be more unwritten extents after that. When ocfs2 grows a file, it zeros the entire cluster in order to ensure future i_size growth will see cleared blocks. Unfortunately, block_write_full_page() drops the pages past i_size. This means that ocfs2 is actually leaking garbage data into the tail end of that last cluster. This is a bug. We adjust ocfs2_write_begin_nolock() and ocfs2_extend_file() to detect when a write or truncate is past i_size. They will use ocfs2_zero_extend() to ensure the data is properly zeroed. Older versions of ocfs2_zero_extend() simply zeroed every block between i_size and the zeroing position. This presumes three things: 1) There is allocation for all of these blocks. 2) The extents are not unwritten. 3) The extents are not refcounted. (1) and (2) hold true for non-sparse filesystems, which used to be the only users of ocfs2_zero_extend(). (3) is another bug. Since we're now using ocfs2_zero_extend() for sparse filesystems as well, we teach ocfs2_zero_extend() to check every extent between i_size and the zeroing position. If the extent is unwritten, it is ignored. If it is refcounted, it is CoWed. Then it is zeroed. Signed-off-by: Joel Becker <joel.becker@oracle.com> Cc: stable@kernel.org
2010-05-21Merge branch 'upstream-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2 * 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (47 commits) ocfs2: Silence a gcc warning. ocfs2: Don't retry xattr set in case value extension fails. ocfs2:dlm: avoid dlm->ast_lock lockres->spinlock dependency break ocfs2: Reset xattr value size after xa_cleanup_value_truncate(). fs/ocfs2/dlm: Use kstrdup fs/ocfs2/dlm: Drop memory allocation cast Ocfs2: Optimize punching-hole code. Ocfs2: Make ocfs2_find_cpos_for_left_leaf() public. Ocfs2: Fix hole punching to correctly do CoW during cluster zeroing. Ocfs2: Optimize ocfs2 truncate to use ocfs2_remove_btree_range() instead. ocfs2: Block signals for mkdir/link/symlink/O_CREAT. ocfs2: Wrap signal blocking in void functions. ocfs2/dlm: Increase o2dlm lockres hash size ocfs2: Make ocfs2_extend_trans() really extend. ocfs2/trivial: Code cleanup for allocation reservation. ocfs2: make ocfs2_adjust_resv_from_alloc simple. ocfs2: Make nointr a default mount option ocfs2/dlm: Make o2dlm domain join/leave messages KERN_NOTICE o2net: log socket state changes ocfs2: print node # when tcp fails ...
2010-05-18Merge branch 'discontig-bg' of git://oss.oracle.com/git/tma/linux-2.6 into ↵Joel Becker
ocfs2-merge-window
2010-05-18Ocfs2: Optimize ocfs2 truncate to use ocfs2_remove_btree_range() instead.Tristan Ye
Truncate is just a special case of punching holes(from new i_size to end), we therefore could take advantage of the existing ocfs2_remove_btree_range() to reduce the comlexity and redundancy in alloc.c. The goal here is to make truncate more generic and straightforward. Several functions only used by ocfs2_commit_truncate() will smiply be removed. ocfs2_remove_btree_range() was originally used by the hole punching code, which didn't take refcount trees into account (definitely a bug). We therefore need to change that func a bit to handle refcount trees. It must take the refcount lock, calculate and reserve blocks for refcount tree changes, and decrease refcounts at the end. We replace ocfs2_lock_allocators() here by adding a new func ocfs2_reserve_blocks_for_rec_trunc() which accepts some extra blocks to reserve. This will not hurt any other code using ocfs2_remove_btree_range() (such as dir truncate and hole punching). I merged the following steps into one patch since they may be logically doing one thing, though I know it looks a little bit fat to review. 1). Remove redundant code used by ocfs2_commit_truncate(), since we're moving to ocfs2_remove_btree_range anyway. 2). Add a new func ocfs2_reserve_blocks_for_rec_trunc() for purpose of accepting some extra blocks to reserve. 3). Change ocfs2_prepare_refcount_change_for_del() a bit to fit our needs. It's safe to do this since it's only being called by truncate. 4). Change ocfs2_remove_btree_range() a bit to take refcount case into account. 5). Finally, we change ocfs2_commit_truncate() to call ocfs2_remove_btree_range() in a proper way. The patch has been tested normally for sanity check, stress tests with heavier workload will be expected. Based on this patch, fixing the punching holes bug will be fairly easy. Signed-off-by: Tristan Ye <tristan.ye@oracle.com> Acked-by: Mark Fasheh <mfasheh@suse.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-06ocfs2: Make ocfs2_extend_trans() really extend.Tao Ma
In ocfs2, we use ocfs2_extend_trans() to extend a journal handle's blocks. But if jbd2_journal_extend() fails, it will only restart with the the new number of blocks. This tends to be awkward since in most cases we want additional reserved blocks. It makes our code harder to mantain since the caller can't be sure all the original blocks will not be accessed and dirtied again. There are 15 callers of ocfs2_extend_trans() in fs/ocfs2, and 12 of them have to add h_buffer_credits before they call ocfs2_extend_trans(). This makes ocfs2_extend_trans() really extend atop the original block count. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-06ocfs2: Make ocfs2_journal_dirty() void.Joel Becker
jbd[2]_journal_dirty_metadata() only returns 0. It's been returning 0 since before the kernel moved to git. There is no point in checking this error. ocfs2_journal_dirty() has been faithfully returning the status since the beginning. All over ocfs2, we have blocks of code checking this can't fail status. In the past few years, we've tried to avoid adding these checks, because they are pointless. But anyone who looks at our code assumes they are needed. Finally, ocfs2_journal_dirty() is made a void function. All error checking is removed from other files. We'll BUG_ON() the status of jbd2_journal_dirty_metadata() just in case they change it someday. They won't. Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-04-30Merge branch 'skip_delete_inode' of ↵Joel Becker
git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2-mark into ocfs2-fixes
2010-04-23ocfs2: Update VFS inode's id info after reflink.Tao Ma
In reflink we update the id info on the disk but forgot to update the corresponding information in the VFS inode. Update them accordingly when we want to preserve the attributes. Reported-by: Jeff Liu <jeff.liu@oracle.com> Signed-off-by: Tao Ma <tao.ma@oracle.com> Cc: <stable@kernel.org> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-22ocfs2: Free block to the right block group.Tao Ma
In case the block we are going to free is allocated from a discontiguous block group, we have to use suballoc_loc to be the right group. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-03-26ocfs2: Set suballoc_loc on allocated metadata.Joel Becker
Get the suballoc_loc from ocfs2_claim_new_inode() or ocfs2_claim_metadata(). Store it on the appropriate field of the block we just allocated. Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-05-06ocfs2: ocfs2_claim_*() don't need an ocfs2_super argument.Joel Becker
They all take an ocfs2_alloc_context, which has the allocation inode. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Tao Ma <tao.ma@oracle.com>
2010-03-17ocfs2: Update i_blocks in reflink operations.Tao Ma
In reflink, we need to upate i_blocks for the target inode. Reported-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-03-05Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: (33 commits) quota: stop using QUOTA_OK / NO_QUOTA dquot: cleanup dquot initialize routine dquot: move dquot initialization responsibility into the filesystem dquot: cleanup dquot drop routine dquot: move dquot drop responsibility into the filesystem dquot: cleanup dquot transfer routine dquot: move dquot transfer responsibility into the filesystem dquot: cleanup inode allocation / freeing routines dquot: cleanup space allocation / freeing routines ext3: add writepage sanity checks ext3: Truncate allocated blocks if direct IO write fails to update i_size quota: Properly invalidate caches even for filesystems with blocksize < pagesize quota: generalize quota transfer interface quota: sb_quota state flags cleanup jbd: Delay discarding buffers in journal_unmap_buffer ext3: quota_write cross block boundary behaviour quota: drop permission checks from xfs_fs_set_xstate/xfs_fs_set_xquota quota: split out compat_sys_quotactl support from quota.c quota: split out netlink notification support from quota.c quota: remove invalid optimization from quota_sync_all ... Fixed trivial conflicts in fs/namei.c and fs/ufs/inode.c
2010-03-04dquot: cleanup dquot initialize routineChristoph Hellwig
Get rid of the initialize dquot operation - it is now always called from the filesystem and if a filesystem really needs it's own (which none currently does) it can just call into it's own routine directly. Rename the now static low-level dquot_initialize helper to __dquot_initialize and vfs_dq_init to dquot_initialize to have a consistent namespace. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2010-02-26ocfs2: add extent block stealing for ocfs2 v5Tiger Yang
This patch add extent block (metadata) stealing mechanism for extent allocation. This mechanism is same as the inode stealing. if no room in slot specific extent_alloc, we will try to allocate extent block from the next slot. Signed-off-by: Tiger Yang <tiger.yang@oracle.com> Acked-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-02-03ocfs2: Only bug out when page size is larger than cluster size.Tao Ma
In CoW, we have to make sure that the page is already written out to the disk. So we have a BUG_ON(PageDirty(page)). In ppc platform we have pagesize=64K, so if the cs=4K, if the file have fragmented clusters, we will map the page many times. See this file as an example. Tree Depth: 0 Count: 19 Next Free Rec: 14 ## Offset Clusters Block# Flags 0 0 4 2164864 0x2 Refcounted 1 4 2 9302792 0x2 Refcounted ... We have to replace the extent recs one by one, so the page with index 0 will be mapped and dirtied twice. I'd like to leave the BUG_ON there while adding a check so that in case we meet with an error in other platforms, we can find it easily. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2010-02-03ocfs2: Fix memory overflow in cow_by_page.Tao Ma
In ocfs2_duplicate_clusters_by_page, we calculate map_end by shifting page_index. But actually in case we meet with a large offset(say in a i686 box, poff_t is only 32 bits and page_index=2056240), we will overflow. So change the type of page_index to loff_t. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-12-23Merge branch 'upstream-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2 * 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: ocfs2: Set i_nlink properly during reflink. ocfs2: Add reflinked file's inode to inode hash eariler. ocfs2: refcounttree.c cleanup. ocfs2: Find proper end cpos for a leaf refcount block.
2009-12-07Merge branch 'for-next' into for-linusJiri Kosina
Conflicts: kernel/irq/chip.c
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-03ocfs2: refcounttree.c cleanup.Tao Ma
sparse check finds some endian problem and some other minor issues. There is an obsolete function which should be removed. So this patch resolve all these. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-12-03ocfs2: Find proper end cpos for a leaf refcount block.Tao Ma
ocfs2 refcount tree is stored as an extent tree while the leaf ocfs2_refcount_rec points to a refcount block. The following step can trip a kernel panic. mkfs.ocfs2 -b 512 -C 1M --fs-features=refcount $DEVICE mount -t ocfs2 $DEVICE $MNT_DIR FILE_NAME=$RANDOM FILE_NAME_1=$RANDOM FILE_REF="${FILE_NAME}_ref" FILE_REF_1="${FILE_NAME}_ref_1" for((i=0;i<305;i++)) do # /mnt/1048576 is a file with 1048576 sizes. cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME_1 done for((i=0;i<3;i++)) do cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME done for((i=0;i<2;i++)) do cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME_1 done cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME for((i=0;i<11;i++)) do cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME cat /mnt/1048576 >> $MNT_DIR/$FILE_NAME_1 done reflink $MNT_DIR/$FILE_NAME $MNT_DIR/$FILE_REF # write_f is a program which will write some bytes to a file at offset. # write_f -f file_name -l offset -w write_bytes. ./write_f -f $MNT_DIR/$FILE_REF -l $[310*1048576] -w 4096 ./write_f -f $MNT_DIR/$FILE_REF -l $[306*1048576] -w 4096 ./write_f -f $MNT_DIR/$FILE_REF -l $[311*1048576] -w 4096 ./write_f -f $MNT_DIR/$FILE_NAME -l $[310*1048576] -w 4096 ./write_f -f $MNT_DIR/$FILE_NAME -l $[311*1048576] -w 4096 reflink $MNT_DIR/$FILE_NAME $MNT_DIR/$FILE_REF_1 ./write_f -f $MNT_DIR/$FILE_NAME -l $[311*1048576] -w 4096 #kernel panic here. The reason is that if the ocfs2_extent_rec is the last record in a leaf extent block, the old solution fails to find the suitable end cpos. So this patch try to walk through the b-tree, find the next sub root and get the c_pos the next sub-tree starts from. btw, I have runned tristan's test case against the patched kernel for several days and this type of kernel panic never happens again. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com>
2009-10-29ocfs2: duplicate inline data properly during reflink.Tao Ma
The old reflink fails to handle inodes with inline data and will oops if it encounters them. This patch copies inline data to the new inode. Extended attributes may still be refcounted. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com> Tested-by: Tristan Ye <tristan.ye@oracle.com>
2009-10-29ocfs2: Move ocfs2_complete_reflink to the right place.Tao Ma
As its name ocfs2_complete_reflink indicates, it should be called after all the work for reflink is done, so it really should be called after we reflink xattr successfully. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Joel Becker <joel.becker@oracle.com> Tested-by: Tristan Ye <tristan.ye@oracle.com>
2009-09-23ocfs2: Add ioctl for reflink.Tao Ma
The ioctl will take 3 parameters: old_path, new_path and preserve and call vfs_reflink. It is useful when we backport reflink features to old kernels. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Implement ocfs2_reflink.Tao Ma
Implement ocfs2_reflink. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add preserve to reflink.Tao Ma
reflink has 2 options for the destination file: 1. snapshot: reflink will attempt to preserve ownership, permissions, and all other security state in order to create a full snapshot. 2. new file: it will acquire the data extent sharing but will see the file's security state and attributes initialized as a new file. So add the option to ocfs2. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Don't merge in 1st refcount ops of reflink.Tao Ma
Actually the whole reflink will touch refcount tree 2 times: 1. It will add the clusters in the extent record to the tree if it isn't refcounted before. 2. It will add 1 refcount to these clusters when it add these extent records to the tree. So actually we shouldn't do merge in the 1st operation since the 2nd one will soon be called and we may have to split it again. Do a merge first and split soon is a waste of time. So we only merge in the 2nd round. This is done by adding a new internal __ocfs2_increase_refcount and call it with "not-merge" for 1st refcount operation in reflink. This also has a side-effect that we don't need to worry too much about the metadata allocation in the 2nd round since it will only merge and no split will happen for those records. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add reflink support for xattr.Tao Ma
Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Call refcount tree remove process properly.Tao Ma
Now with xattr refcount support, we need to check whether we have xattr refcounted before we remove the refcount tree. Now the mechanism is: 1) Check whether i_clusters == 0, if no, exit. 2) check whether we have i_xattr_loc in dinode. if yes, exit. 2) Check whether we have inline xattr stored outside, if yes, exit. 4) Remove the tree. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Attach xattr clusters to refcount tree.Tao Ma
In ocfs2, when xattr's value is larger than OCFS2_XATTR_INLINE_SIZE, it will be kept outside of the blocks we store xattr entry. And they are stored in a b-tree also. So this patch try to attach all these clusters to refcount tree also. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add CoW support for xattr.Tao Ma
In order to make 2 transcation(xattr and cow) independent with each other, we CoW the whole xattr out in case we are setting them. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Abstract duplicate clusters process in CoW.Tao Ma
We currently use pagecache to duplicate clusters in CoW, but it isn't suitable for xattr case. So abstract it out so that the caller can decide which method it use. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: handle file attributes issue for reflink.Tao Ma
A reflink creates a snapshot of a file, that means the attributes must be identical except for three exceptions - nlink, ino, and ctime. As for time changes, Here is a brief description: 1. Source file: 1) atime: Ignore. Let the lazy atime code handle that. 2) mtime: don't touch. 3) ctime: If we change the tree (adding REFCOUNTED to at least one extent), update it. 2. Destination file: 1) atime: ignore. 2) mtime: we want it to appear identical to the source. 3) ctime: update. The idea here is that an ls -l will show the same time for the src and target - it shows mtime. Backup software like rsync and tar will treat the new file correctly too. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add normal functions for reflink a normal file's extents.Tao Ma
2 major functions are added in this patch. ocfs2_attach_refcount_tree will create a new refcount tree to the old file if it doesn't have one and insert all the extent records to the tree if they are not refcounted. ocfs2_create_reflink_node will: 1. set the refcount tree to the new file. 2. call ocfs2_duplicate_extent_list which will iterate all the extents for the old file, insert it to the new file and increase the corresponding referennce count. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: CoW a reflinked cluster when it is truncated.Tao Ma
When we truncate a file to a specific size which resides in a reflinked cluster, we need to CoW it since ocfs2_zero_range_for_truncate will zero the space after the size(just another type of write). So we add a "max_cpos" in ocfs2_refcount_cow so that it will stop when it hit the max cluster offset. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: CoW refcount tree improvement.Tao Ma
During CoW, if the old extent record is refcounted, we allocate som new clusters and do CoW. Actually we can have some improvement here. If the old extent has refcount=1, that means now it is only used by this file. So we don't need to allocate new clusters, just remove the refcounted flag and it is OK. We also have to remove it from the refcount tree while not deleting it. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add CoW support.Tao Ma
This patch try CoW support for a refcounted record. the whole process will be: 1. Calculate how many clusters we need to CoW and where we start. Extents that are not completely encompassed by the write will be broken on 1MB boundaries. 2. Do CoW for the clusters with the help of page cache. 3. Change the b-tree structure with the new allocated clusters. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Decrement refcount when truncating refcounted extents.Tao Ma
Add 'Decrement refcount for delete' in to the normal truncate process. So for a refcounted extent record, call refcount rec decrementation instead of cluster free. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add functions for extents refcounted.Tao Ma
Add function ocfs2_mark_extent_refcounted which can mark an extent refcounted. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add support of decrementing refcount for delete.Tao Ma
Given a physical cpos and length, decrement the refcount in the tree. If the refcount for any portion of the extent goes to zero, that portion is queued for freeing. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add support for incrementing refcount in the tree.Tao Ma
Given a physical cpos and length, increment the refcount in the tree. If the extent has not been seen before, a refcount record is created for it. Refcount records may be merged or split by this operation. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Basic tree root operation.Tao Ma
Add basic refcount tree root operation. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add refcount tree lock mechanism.Tao Ma
Implement locking around struct ocfs2_refcount_tree. This protects all read/write operations on refcount trees. ocfs2_refcount_tree has its own lock and its own caching_info, protecting buffers among multiple nodes. User must call ocfs2_lock_refcount_tree before his operation on the tree and unlock it after that. ocfs2_refcount_trees are referenced by the block number of the refcount tree root block, So we create an rb-tree on the ocfs2_super to look them up. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add caching info for refcount tree.Tao Ma
refcount tree should use its own caching info so that when we downconvert the refcount tree lock, we can drop all the cached buffer head. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-23ocfs2: Add ocfs2_read_refcount_block.Tao Ma
Signed-off-by: Tao Ma <tao.ma@oracle.com>