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2014-10-04Merge branch 'cleanup/misc-for-3.18' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus Signed-off-by: Chris Mason <clm@fb.com> Conflicts: fs/btrfs/extent_io.c
2014-10-03Btrfs: be aware of btree inode write errors to avoid fs corruptionFilipe Manana
While we have a transaction ongoing, the VM might decide at any time to call btree_inode->i_mapping->a_ops->writepages(), which will start writeback of dirty pages belonging to btree nodes/leafs. This call might return an error or the writeback might finish with an error before we attempt to commit the running transaction. If this happens, we might have no way of knowing that such error happened when we are committing the transaction - because the pages might no longer be marked dirty nor tagged for writeback (if a subsequent modification to the extent buffer didn't happen before the transaction commit) which makes filemap_fdata[write|wait]_range unable to find such pages (even if they're marked with SetPageError). So if this happens we must abort the transaction, otherwise we commit a super block with btree roots that point to btree nodes/leafs whose content on disk is invalid - either garbage or the content of some node/leaf from a past generation that got cowed or deleted and is no longer valid (for this later case we end up getting error messages like "parent transid verify failed on 10826481664 wanted 25748 found 29562" when reading btree nodes/leafs from disk). Note that setting and checking AS_EIO/AS_ENOSPC in the btree inode's i_mapping would not be enough because we need to distinguish between log tree extents (not fatal) vs non-log tree extents (fatal) and because the next call to filemap_fdatawait_range() will catch and clear such errors in the mapping - and that call might be from a log sync and not from a transaction commit, which means we would not know about the error at transaction commit time. Also, checking for the eb flag EXTENT_BUFFER_IOERR at transaction commit time isn't done and would not be completely reliable, as the eb might be removed from memory and read back when trying to get it, which clears that flag right before reading the eb's pages from disk, making us not know about the previous write error. Using the new 3 flags for the btree inode also makes us achieve the goal of AS_EIO/AS_ENOSPC when writepages() returns success, started writeback for all dirty pages and before filemap_fdatawait_range() is called, the writeback for all dirty pages had already finished with errors - because we were not using AS_EIO/AS_ENOSPC, filemap_fdatawait_range() would return success, as it could not know that writeback errors happened (the pages were no longer tagged for writeback). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-03Btrfs: fix crash of btrfs_release_extent_buffer_pageLiu Bo
This is actually inspired by Filipe's patch. When write_one_eb() fails on submit_extent_page(), it'll give up writing this eb and mark it with EXTENT_BUFFER_IOERR. So if it's not the last page that encounter the failure, there are some left pages which remain DIRTY, and if a later COW on this eb happens, ie. eb is COWed and freed, it'd run into BUG_ON in btrfs_release_extent_buffer_page() for the DIRTY page, ie. BUG_ON(PageDirty(page)); This adds the missing clear_page_dirty_for_io() for the rest pages of eb. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-03Btrfs: add missing end_page_writeback on submit_extent_page failureFilipe Manana
If submit_extent_page() fails in write_one_eb(), we end up with the current page not marked dirty anymore, unlocked and marked for writeback. But we never end up calling end_page_writeback() against the page, which will make calls to filemap_fdatawait_range (e.g. at transaction commit time) hang forever waiting for the writeback bit to be cleared from the page. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-10-02btrfs: kill extent_buffer_page helperDavid Sterba
It used to be more complex but now it's just a simple array access. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-10-02btrfs: drop constant param from btrfs_release_extent_buffer_pageDavid Sterba
All callers use the same value, simplify the function. Signed-off-by: David Sterba <dsterba@suse.cz>
2014-09-17Btrfs: cleanup the read failure record after write or when the inode is freeingMiao Xie
After the data is written successfully, we should cleanup the read failure record in that range because - If we set data COW for the file, the range that the failure record pointed to is mapped to a new place, so it is invalid. - If we set no data COW for the file, and if there is no error during writting, the corrupted data is corrected, so the failure record can be removed. And if some errors happen on the mirrors, we also needn't worry about it because the failure record will be recreated if we read the same place again. Sometimes, we may fail to correct the data, so the failure records will be left in the tree, we need free them when we free the inode or the memory leak happens. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: implement repair function when direct read failsMiao Xie
This patch implement data repair function when direct read fails. The detail of the implementation is: - When we find the data is not right, we try to read the data from the other mirror. - When the io on the mirror ends, we will insert the endio work into the dedicated btrfs workqueue, not common read endio workqueue, because the original endio work is still blocked in the btrfs endio workqueue, if we insert the endio work of the io on the mirror into that workqueue, deadlock would happen. - After we get right data, we write it back to the corrupted mirror. - And if the data on the new mirror is still corrupted, we will try next mirror until we read right data or all the mirrors are traversed. - After the above work, we set the uptodate flag according to the result. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: modify clean_io_failure and make it suit direct ioMiao Xie
We could not use clean_io_failure in the direct IO path because it got the filesystem information from the page structure, but the page in the direct IO bio didn't have the filesystem information in its structure. So we need modify it and pass all the information it need by parameters. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: modify repair_io_failure and make it suit direct ioMiao Xie
The original code of repair_io_failure was just used for buffered read, because it got some filesystem data from page structure, it is safe for the page in the page cache. But when we do a direct read, the pages in bio are not in the page cache, that is there is no filesystem data in the page structure. In order to implement direct read data repair, we need modify repair_io_failure and pass all filesystem data it need by function parameters. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: split bio_readpage_error into several functionsMiao Xie
The data repair function of direct read will be implemented later, and some code in bio_readpage_error will be reused, so split bio_readpage_error into several functions which will be used in direct read repair later. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: Cleanup unused variant and argument of IO failure handlersMiao Xie
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: fix missing error handler if submiting re-read bio failsMiao Xie
We forgot to free failure record and bio after submitting re-read bio failed, fix it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: do file data check by sub-bio's selfMiao Xie
Direct IO splits the original bio to several sub-bios because of the limit of raid stripe, and the filesystem will wait for all sub-bios and then run final end io process. But it was very hard to implement the data repair when dio read failure happens, because at the final end io function, we didn't know which mirror the data was read from. So in order to implement the data repair, we have to move the file data check in the final end io function to the sub-bio end io function, in which we can get the mirror number of the device we access. This patch did this work as the first step of the direct io data repair implementation. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: load checksum data once when submitting a direct read ioMiao Xie
The current code would load checksum data for several times when we split a whole direct read io because of the limit of the raid stripe, it would make us search the csum tree for several times. In fact, it just wasted time, and made the contention of the csum tree root be more serious. This patch improves this problem by loading the data at once. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: make fiemap not blow when you have lots of snapshotsJosef Bacik
We have been iterating all references for each extent we have in a file when we do fiemap to see if it is shared. This is fine when you have a few clones or a few snapshots, but when you have 5k snapshots suddenly fiemap just sits there and stares at you. So add btrfs_check_shared which will use the backref walking code but will short circuit as soon as it finds a root or inode that doesn't match the one we currently have. This makes fiemap on my testbox go from looking at me blankly for a day to spitting out actual output in a reasonable amount of time. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: cleanup the same name in end_bio_extent_readpageLiu Bo
We've defined a 'offset' out of bio_for_each_segment_all. This is just a clean rename, no function changes. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17Btrfs: reduce size of struct extent_stateFilipe Manana
The tree field of struct extent_state was only used to figure out if an extent state was connected to an inode's io tree or not. For this we can just use the rb_node field itself. On a x86_64 system with this change the sizeof(struct extent_state) is reduced from 96 bytes down to 88 bytes, meaning that with a page size of 4096 bytes we can now store 46 extent states per page instead of 42. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-09-17btrfs: kill the key type accessor helpersDavid Sterba
btrfs_set_key_type and btrfs_key_type are used inconsistently along with open coded variants. Other members of btrfs_key are accessed directly without any helpers anyway. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-27Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "The biggest of these comes from Liu Bo, who tracked down a hang we've been hitting since moving to kernel workqueues (it's a btrfs bug, not in the generic code). His patch needs backporting to 3.16 and 3.15 stable, which I'll send once this is in. Otherwise these are assorted fixes. Most were integrated last week during KS, but I wanted to give everyone the chance to test the result, so I waited for rc2 to come out before sending" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (24 commits) Btrfs: fix task hang under heavy compressed write Btrfs: fix filemap_flush call in btrfs_file_release Btrfs: fix crash on endio of reading corrupted block btrfs: fix leak in qgroup_subtree_accounting() error path btrfs: Use right extent length when inserting overlap extent map. Btrfs: clone, don't create invalid hole extent map Btrfs: don't monopolize a core when evicting inode Btrfs: fix hole detection during file fsync Btrfs: ensure tmpfile inode is always persisted with link count of 0 Btrfs: race free update of commit root for ro snapshots Btrfs: fix regression of btrfs device replace Btrfs: don't consider the missing device when allocating new chunks Btrfs: Fix wrong device size when we are resizing the device Btrfs: don't write any data into a readonly device when scrub Btrfs: Fix the problem that the replace destroys the seed filesystem btrfs: Return right extent when fiemap gives unaligned offset and len. Btrfs: fix wrong extent mapping for DirectIO Btrfs: fix wrong write range for filemap_fdatawrite_range() Btrfs: fix wrong missing device counter decrease Btrfs: fix unzeroed members in fs_devices when creating a fs from seed fs ...
2014-08-21Btrfs: fix crash on endio of reading corrupted blockLiu Bo
The crash is ------------[ cut here ]------------ kernel BUG at fs/btrfs/extent_io.c:2124! [...] Workqueue: btrfs-endio normal_work_helper [btrfs] RIP: 0010:[<ffffffffa02d6055>] [<ffffffffa02d6055>] end_bio_extent_readpage+0xb45/0xcd0 [btrfs] This is in fact a regression. It is because we forgot to increase @offset properly in reading corrupted block, so that the @offset remains, and this leads to checksum errors while reading left blocks queued up in the same bio, and then ends up with hiting the above BUG_ON. Reported-by: Chris Murphy <lists@colorremedies.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-19btrfs: Return right extent when fiemap gives unaligned offset and len.Qu Wenruo
When page aligned start and len passed to extent_fiemap(), the result is good, but when start and len is not aligned, e.g. start = 1 and len = 4095 is passed to extent_fiemap(), it returns no extent. The problem is that start and len is all rounded down which causes the problem. This patch will round down start and round up (start + len) to return right extent. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2014-07-16sched: Remove proliferation of wait_on_bit() action functionsNeilBrown
The current "wait_on_bit" interface requires an 'action' function to be provided which does the actual waiting. There are over 20 such functions, many of them identical. Most cases can be satisfied by one of just two functions, one which uses io_schedule() and one which just uses schedule(). So: Rename wait_on_bit and wait_on_bit_lock to wait_on_bit_action and wait_on_bit_lock_action to make it explicit that they need an action function. Introduce new wait_on_bit{,_lock} and wait_on_bit{,_lock}_io which are *not* given an action function but implicitly use a standard one. The decision to error-out if a signal is pending is now made based on the 'mode' argument rather than being encoded in the action function. All instances of the old wait_on_bit and wait_on_bit_lock which can use the new version have been changed accordingly and their action functions have been discarded. wait_on_bit{_lock} does not return any specific error code in the event of a signal so the caller must check for non-zero and interpolate their own error code as appropriate. The wait_on_bit() call in __fscache_wait_on_invalidate() was ambiguous as it specified TASK_UNINTERRUPTIBLE but used fscache_wait_bit_interruptible as an action function. David Howells confirms this should be uniformly "uninterruptible" The main remaining user of wait_on_bit{,_lock}_action is NFS which needs to use a freezer-aware schedule() call. A comment in fs/gfs2/glock.c notes that having multiple 'action' functions is useful as they display differently in the 'wchan' field of 'ps'. (and /proc/$PID/wchan). As the new bit_wait{,_io} functions are tagged "__sched", they will not show up at all, but something higher in the stack. So the distinction will still be visible, only with different function names (gds2_glock_wait versus gfs2_glock_dq_wait in the gfs2/glock.c case). Since first version of this patch (against 3.15) two new action functions appeared, on in NFS and one in CIFS. CIFS also now uses an action function that makes the same freezer aware schedule call as NFS. Signed-off-by: NeilBrown <neilb@suse.de> Acked-by: David Howells <dhowells@redhat.com> (fscache, keys) Acked-by: Steven Whitehouse <swhiteho@redhat.com> (gfs2) Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Steve French <sfrench@samba.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140707051603.28027.72349.stgit@notabene.brown Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull more btrfs updates from Chris Mason: "This has a few fixes since our last pull and a new ioctl for doing btree searches from userland. It's very similar to the existing ioctl, but lets us return larger items back down to the app" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: fix error handling in create_pending_snapshot btrfs: fix use of uninit "ret" in end_extent_writepage() btrfs: free ulist in qgroup_shared_accounting() error path Btrfs: fix qgroups sanity test crash or hang btrfs: prevent RCU warning when dereferencing radix tree slot Btrfs: fix unfinished readahead thread for raid5/6 degraded mounting btrfs: new ioctl TREE_SEARCH_V2 btrfs: tree_search, search_ioctl: direct copy to userspace btrfs: new function read_extent_buffer_to_user btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW btrfs: tree_search, copy_to_sk: return EOVERFLOW for too small buffer btrfs: tree_search, search_ioctl: accept varying buffer btrfs: tree_search: eliminate redundant nr_items check
2014-06-13btrfs: fix use of uninit "ret" in end_extent_writepage()Eric Sandeen
If this condition in end_extent_writepage() is false: if (tree->ops && tree->ops->writepage_end_io_hook) we will then test an uninitialized "ret" at: ret = ret < 0 ? ret : -EIO; The test for ret is for the case where ->writepage_end_io_hook failed, and we'd choose that ret as the error; but if there is no ->writepage_end_io_hook, nothing sets ret. Initializing ret to 0 should be sufficient; if writepage_end_io_hook wasn't set, (!uptodate) means non-zero err was passed in, so we choose -EIO in that case. Signed-of-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-13btrfs: new function read_extent_buffer_to_userGerhard Heift
This new function reads the content of an extent directly to user memory. Signed-off-by: Gerhard Heift <Gerhard@Heift.Name> Signed-off-by: Chris Mason <clm@fb.com> Acked-by: David Sterba <dsterba@suse.cz>
2014-06-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "The biggest change here is Josef's rework of the btrfs quota accounting, which improves the in-memory tracking of delayed extent operations. I had been working on Btrfs stack usage for a while, mostly because it had become impossible to do long stress runs with slab, lockdep and pagealloc debugging turned on without blowing the stack. Even though you upgraded us to a nice king sized stack, I kept most of the patches. We also have some very hard to find corruption fixes, an awesome sysfs use after free, and the usual assortment of optimizations, cleanups and other fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (80 commits) Btrfs: convert smp_mb__{before,after}_clear_bit Btrfs: fix scrub_print_warning to handle skinny metadata extents Btrfs: make fsync work after cloning into a file Btrfs: use right type to get real comparison Btrfs: don't check nodes for extent items Btrfs: don't release invalid page in btrfs_page_exists_in_range() Btrfs: make sure we retry if page is a retriable exception Btrfs: make sure we retry if we couldn't get the page btrfs: replace EINVAL with EOPNOTSUPP for dev_replace raid56 trivial: fs/btrfs/ioctl.c: fix typo s/substract/subtract/ Btrfs: fix leaf corruption after __btrfs_drop_extents Btrfs: ensure btrfs_prev_leaf doesn't miss 1 item Btrfs: fix clone to deal with holes when NO_HOLES feature is enabled btrfs: free delayed node outside of root->inode_lock btrfs: replace EINVAL with ERANGE for resize when ULLONG_MAX Btrfs: fix transaction leak during fsync call btrfs: Avoid trucating page or punching hole in a already existed hole. Btrfs: update commit root on snapshot creation after orphan cleanup Btrfs: ioctl, don't re-lock extent range when not necessary Btrfs: avoid visiting all extent items when cloning a range ...
2014-06-10Btrfs: split up __extent_writepage to lower stack usageChris Mason
__extent_writepage has two unrelated parts. First it does the delayed allocation dance and second it does the mapping and IO for the page we're actually writing. This splits it up into those two parts so the stack from one doesn't impact the stack from the other. Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: cut down stack usage in btree_write_cache_pagesChris Mason
This adds noinline_for_stack to two helpers used by btree_write_cache_pages. It shaves us down from 424 bytes on the stack to 280. Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: fix double free in find_lock_delalloc_rangeChris Mason
We need to NULL the cached_state after freeing it, otherwise we might free it again if find_delalloc_range doesn't find anything. Signed-off-by: Chris Mason <clm@fb.com> cc: stable@vger.kernel.org
2014-06-10Btrfs: add sanity tests for new qgroup accounting codeJosef Bacik
This exercises the various parts of the new qgroup accounting code. We do some basic stuff and do some things with the shared refs to make sure all that code works. I had to add a bunch of infrastructure because I needed to be able to insert items into a fake tree without having to do all the hard work myself, hopefully this will be usefull in the future. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: mark mapping with error flag to report errors to userspaceLiu Bo
According to commit 865ffef3797da2cac85b3354b5b6050dc9660978 (fs: fix fsync() error reporting), it's not stable to just check error pages because pages can be truncated or invalidated, we should also mark mapping with error flag so that a later fsync can catch the error. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-10Btrfs: fix hang on error (such as ENOSPC) when writing extent pagesFilipe Manana
When running low on available disk space and having several processes doing buffered file IO, I got the following trace in dmesg: [ 4202.720152] INFO: task kworker/u8:1:5450 blocked for more than 120 seconds. [ 4202.720401] Not tainted 3.13.0-fdm-btrfs-next-26+ #1 [ 4202.720596] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4202.720874] kworker/u8:1 D 0000000000000001 0 5450 2 0x00000000 [ 4202.720904] Workqueue: btrfs-flush_delalloc normal_work_helper [btrfs] [ 4202.720908] ffff8801f62ddc38 0000000000000082 ffff880203ac2490 00000000001d3f40 [ 4202.720913] ffff8801f62ddfd8 00000000001d3f40 ffff8800c4f0c920 ffff880203ac2490 [ 4202.720918] 00000000001d4a40 ffff88020fe85a40 ffff88020fe85ab8 0000000000000001 [ 4202.720922] Call Trace: [ 4202.720931] [<ffffffff816a3cb9>] schedule+0x29/0x70 [ 4202.720950] [<ffffffffa01ec48d>] btrfs_start_ordered_extent+0x6d/0x110 [btrfs] [ 4202.720956] [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0 [ 4202.720972] [<ffffffffa01ec559>] btrfs_run_ordered_extent_work+0x29/0x40 [btrfs] [ 4202.720988] [<ffffffffa0201987>] normal_work_helper+0x137/0x2c0 [btrfs] [ 4202.720994] [<ffffffff810680e5>] process_one_work+0x1f5/0x530 (...) [ 4202.721027] 2 locks held by kworker/u8:1/5450: [ 4202.721028] #0: (%s-%s){++++..}, at: [<ffffffff81068083>] process_one_work+0x193/0x530 [ 4202.721037] #1: ((&work->normal_work)){+.+...}, at: [<ffffffff81068083>] process_one_work+0x193/0x530 [ 4202.721054] INFO: task btrfs:7891 blocked for more than 120 seconds. [ 4202.721258] Not tainted 3.13.0-fdm-btrfs-next-26+ #1 [ 4202.721444] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 4202.721699] btrfs D 0000000000000001 0 7891 7890 0x00000001 [ 4202.721704] ffff88018c2119e8 0000000000000086 ffff8800a33d2490 00000000001d3f40 [ 4202.721710] ffff88018c211fd8 00000000001d3f40 ffff8802144b0000 ffff8800a33d2490 [ 4202.721714] ffff8800d8576640 ffff88020fe85bc0 ffff88020fe85bc8 7fffffffffffffff [ 4202.721718] Call Trace: [ 4202.721723] [<ffffffff816a3cb9>] schedule+0x29/0x70 [ 4202.721727] [<ffffffff816a2ebc>] schedule_timeout+0x1dc/0x270 [ 4202.721732] [<ffffffff8109bd79>] ? mark_held_locks+0xb9/0x140 [ 4202.721736] [<ffffffff816a90c0>] ? _raw_spin_unlock_irq+0x30/0x40 [ 4202.721740] [<ffffffff8109bf0d>] ? trace_hardirqs_on_caller+0x10d/0x1d0 [ 4202.721744] [<ffffffff816a488f>] wait_for_completion+0xdf/0x120 [ 4202.721749] [<ffffffff8107fa90>] ? try_to_wake_up+0x310/0x310 [ 4202.721765] [<ffffffffa01ebee4>] btrfs_wait_ordered_extents+0x1f4/0x280 [btrfs] [ 4202.721781] [<ffffffffa020526e>] btrfs_mksubvol.isra.62+0x30e/0x5a0 [btrfs] [ 4202.721786] [<ffffffff8108e620>] ? bit_waitqueue+0xc0/0xc0 [ 4202.721799] [<ffffffffa02056a9>] btrfs_ioctl_snap_create_transid+0x1a9/0x1b0 [btrfs] [ 4202.721813] [<ffffffffa020583a>] btrfs_ioctl_snap_create_v2+0x10a/0x170 [btrfs] (...) It turns out that extent_io.c:__extent_writepage(), which ends up being called through filemap_fdatawrite_range() in btrfs_start_ordered_extent(), was getting -ENOSPC when calling the fill_delalloc callback. In this situation, it returned without the writepage_end_io_hook callback (inode.c:btrfs_writepage_end_io_hook) ever being called for the respective page, which prevents the ordered extent's bytes_left count from ever reaching 0, and therefore a finish_ordered_fn work is never queued into the endio_write_workers queue. This makes the task that called btrfs_start_ordered_extent() hang forever on the wait queue of the ordered extent. This is fairly easy to reproduce using a small filesystem and fsstress on a quad core vm: mkfs.btrfs -f -b `expr 2100 \* 1024 \* 1024` /dev/sdd mount /dev/sdd /mnt fsstress -p 6 -d /mnt -n 100000 -x \ "btrfs subvolume snapshot -r /mnt /mnt/mysnap" \ -f allocsp=0 \ -f bulkstat=0 \ -f bulkstat1=0 \ -f chown=0 \ -f creat=1 \ -f dread=0 \ -f dwrite=0 \ -f fallocate=1 \ -f fdatasync=0 \ -f fiemap=0 \ -f freesp=0 \ -f fsync=0 \ -f getattr=0 \ -f getdents=0 \ -f link=0 \ -f mkdir=0 \ -f mknod=0 \ -f punch=1 \ -f read=0 \ -f readlink=0 \ -f rename=0 \ -f resvsp=0 \ -f rmdir=0 \ -f setxattr=0 \ -f stat=0 \ -f symlink=0 \ -f sync=0 \ -f truncate=1 \ -f unlink=0 \ -f unresvsp=0 \ -f write=4 So just ensure that if an error happens while writing the extent page we call the writepage_end_io_hook callback. Also make it return the error code and ensure the caller (extent_write_cache_pages) processes all pages in the page vector even if an error happens only for some of them, so that ordered extents end up released. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-04mm: non-atomically mark page accessed during page cache allocation where ↵Mel Gorman
possible aops->write_begin may allocate a new page and make it visible only to have mark_page_accessed called almost immediately after. Once the page is visible the atomic operations are necessary which is noticable overhead when writing to an in-memory filesystem like tmpfs but should also be noticable with fast storage. The objective of the patch is to initialse the accessed information with non-atomic operations before the page is visible. The bulk of filesystems directly or indirectly use grab_cache_page_write_begin or find_or_create_page for the initial allocation of a page cache page. This patch adds an init_page_accessed() helper which behaves like the first call to mark_page_accessed() but may called before the page is visible and can be done non-atomically. The primary APIs of concern in this care are the following and are used by most filesystems. find_get_page find_lock_page find_or_create_page grab_cache_page_nowait grab_cache_page_write_begin All of them are very similar in detail to the patch creates a core helper pagecache_get_page() which takes a flags parameter that affects its behavior such as whether the page should be marked accessed or not. Then old API is preserved but is basically a thin wrapper around this core function. Each of the filesystems are then updated to avoid calling mark_page_accessed when it is known that the VM interfaces have already done the job. There is a slight snag in that the timing of the mark_page_accessed() has now changed so in rare cases it's possible a page gets to the end of the LRU as PageReferenced where as previously it might have been repromoted. This is expected to be rare but it's worth the filesystem people thinking about it in case they see a problem with the timing change. It is also the case that some filesystems may be marking pages accessed that previously did not but it makes sense that filesystems have consistent behaviour in this regard. The test case used to evaulate this is a simple dd of a large file done multiple times with the file deleted on each iterations. The size of the file is 1/10th physical memory to avoid dirty page balancing. In the async case it will be possible that the workload completes without even hitting the disk and will have variable results but highlight the impact of mark_page_accessed for async IO. The sync results are expected to be more stable. The exception is tmpfs where the normal case is for the "IO" to not hit the disk. The test machine was single socket and UMA to avoid any scheduling or NUMA artifacts. Throughput and wall times are presented for sync IO, only wall times are shown for async as the granularity reported by dd and the variability is unsuitable for comparison. As async results were variable do to writback timings, I'm only reporting the maximum figures. The sync results were stable enough to make the mean and stddev uninteresting. The performance results are reported based on a run with no profiling. Profile data is based on a separate run with oprofile running. async dd 3.15.0-rc3 3.15.0-rc3 vanilla accessed-v2 ext3 Max elapsed 13.9900 ( 0.00%) 11.5900 ( 17.16%) tmpfs Max elapsed 0.5100 ( 0.00%) 0.4900 ( 3.92%) btrfs Max elapsed 12.8100 ( 0.00%) 12.7800 ( 0.23%) ext4 Max elapsed 18.6000 ( 0.00%) 13.3400 ( 28.28%) xfs Max elapsed 12.5600 ( 0.00%) 2.0900 ( 83.36%) The XFS figure is a bit strange as it managed to avoid a worst case by sheer luck but the average figures looked reasonable. samples percentage ext3 86107 0.9783 vmlinux-3.15.0-rc4-vanilla mark_page_accessed ext3 23833 0.2710 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed ext3 5036 0.0573 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed ext4 64566 0.8961 vmlinux-3.15.0-rc4-vanilla mark_page_accessed ext4 5322 0.0713 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed ext4 2869 0.0384 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed xfs 62126 1.7675 vmlinux-3.15.0-rc4-vanilla mark_page_accessed xfs 1904 0.0554 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed xfs 103 0.0030 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed btrfs 10655 0.1338 vmlinux-3.15.0-rc4-vanilla mark_page_accessed btrfs 2020 0.0273 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed btrfs 587 0.0079 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed tmpfs 59562 3.2628 vmlinux-3.15.0-rc4-vanilla mark_page_accessed tmpfs 1210 0.0696 vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed tmpfs 94 0.0054 vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed [akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer] Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Tested-by: Prabhakar Lad <prabhakar.csengg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-18arch: Mass conversion of smp_mb__*()Peter Zijlstra
Mostly scripted conversion of the smp_mb__* barriers. Signed-off-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Link: http://lkml.kernel.org/n/tip-55dhyhocezdw1dg7u19hmh1u@git.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-arch@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-11Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull second set of btrfs updates from Chris Mason: "The most important changes here are from Josef, fixing a btrfs regression in 3.14 that can cause corruptions in the extent allocation tree when snapshots are in use. Josef also fixed some deadlocks in send/recv and other assorted races when balance is running" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (23 commits) Btrfs: fix compile warnings on on avr32 platform btrfs: allow mounting btrfs subvolumes with different ro/rw options btrfs: export global block reserve size as space_info btrfs: fix crash in remount(thread_pool=) case Btrfs: abort the transaction when we don't find our extent ref Btrfs: fix EINVAL checks in btrfs_clone Btrfs: fix unlock in __start_delalloc_inodes() Btrfs: scrub raid56 stripes in the right way Btrfs: don't compress for a small write Btrfs: more efficient io tree navigation on wait_extent_bit Btrfs: send, build path string only once in send_hole btrfs: filter invalid arg for btrfs resize Btrfs: send, fix data corruption due to incorrect hole detection Btrfs: kmalloc() doesn't return an ERR_PTR Btrfs: fix snapshot vs nocow writting btrfs: Change the expanding write sequence to fix snapshot related bug. btrfs: make device scan less noisy btrfs: fix lockdep warning with reclaim lock inversion Btrfs: hold the commit_root_sem when getting the commit root during send Btrfs: remove transaction from send ...
2014-04-07Btrfs: more efficient io tree navigation on wait_extent_bitFilipe Manana
If we don't reschedule use rb_next to find the next extent state instead of a full tree search, which is more efficient and safe since we didn't release the io tree's lock. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-04-07Btrfs: don't clear uptodate if the eb is under IOJosef Bacik
So I have an awful exercise script that will run snapshot, balance and send/receive in parallel. This sometimes would crash spectacularly and when it came back up the fs would be completely hosed. Turns out this is because of a bad interaction of balance and send/receive. Send will hold onto its entire path for the whole send, but its blocks could get relocated out from underneath it, and because it doesn't old tree locks theres nothing to keep this from happening. So it will go to read in a slot with an old transid, and we could have re-allocated this block for something else and it could have a completely different transid. But because we think it is invalid we clear uptodate and re-read in the block. If we do this before we actually write out the new block we could write back stale data to the fs, and boom we're screwed. Now we definitely need to fix this disconnect between send and balance, but we really really need to not allow ourselves to accidently read in stale data over new data. So make sure we check if the extent buffer is not under io before clearing uptodate, this will kick back EIO to the caller instead of reading in stale data and keep us from corrupting the fs. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-04-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs changes from Chris Mason: "This is a pretty long stream of bug fixes and performance fixes. Qu Wenruo has replaced the btrfs async threads with regular kernel workqueues. We'll keep an eye out for performance differences, but it's nice to be using more generic code for this. We still have some corruption fixes and other patches coming in for the merge window, but this batch is tested and ready to go" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (108 commits) Btrfs: fix a crash of clone with inline extents's split btrfs: fix uninit variable warning Btrfs: take into account total references when doing backref lookup Btrfs: part 2, fix incremental send's decision to delay a dir move/rename Btrfs: fix incremental send's decision to delay a dir move/rename Btrfs: remove unnecessary inode generation lookup in send Btrfs: fix race when updating existing ref head btrfs: Add trace for btrfs_workqueue alloc/destroy Btrfs: less fs tree lock contention when using autodefrag Btrfs: return EPERM when deleting a default subvolume Btrfs: add missing kfree in btrfs_destroy_workqueue Btrfs: cache extent states in defrag code path Btrfs: fix deadlock with nested trans handles Btrfs: fix possible empty list access when flushing the delalloc inodes Btrfs: split the global ordered extents mutex Btrfs: don't flush all delalloc inodes when we doesn't get s_umount lock Btrfs: reclaim delalloc metadata more aggressively Btrfs: remove unnecessary lock in may_commit_transaction() Btrfs: remove the unnecessary flush when preparing the pages Btrfs: just do dirty page flush for the inode with compression before direct IO ...
2014-03-10Btrfs: more efficient split extent state insertionFilipe Manana
When we split an extent state there's no need to start the rbtree search from the root node - we can start it from the original extent state node, since we would end up in its subtree if we do the search starting at the root node anyway. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com>
2014-03-10Btrfs: remove unneeded field / smaller extent_map structureFilipe Manana
We don't need to have an unsigned int field in the extent_map struct to tell us whether the extent map is in the inode's extent_map tree or not. We can use the rb_node struct field and the RB_CLEAR_NODE and RB_EMPTY_NODE macros to achieve the same task. This reduces sizeof(struct extent_map) from 152 bytes to 144 bytes (on a 64 bits system). Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Reviewed-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fb.com>
2014-01-31Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "This is a pretty big pull, and most of these changes have been floating in btrfs-next for a long time. Filipe's properties work is a cool building block for inheriting attributes like compression down on a per inode basis. Jeff Mahoney kicked in code to export filesystem info into sysfs. Otherwise, lots of performance improvements, cleanups and bug fixes. Looks like there are still a few other small pending incrementals, but I wanted to get the bulk of this in first" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (149 commits) Btrfs: fix spin_unlock in check_ref_cleanup Btrfs: setup inode location during btrfs_init_inode_locked Btrfs: don't use ram_bytes for uncompressed inline items Btrfs: fix btrfs_search_slot_for_read backwards iteration Btrfs: do not export ulist functions Btrfs: rework ulist with list+rb_tree Btrfs: fix memory leaks on walking backrefs failure Btrfs: fix send file hole detection leading to data corruption Btrfs: add a reschedule point in btrfs_find_all_roots() Btrfs: make send's file extent item search more efficient Btrfs: fix to catch all errors when resolving indirect ref Btrfs: fix protection between walking backrefs and root deletion btrfs: fix warning while merging two adjacent extents Btrfs: fix infinite path build loops in incremental send btrfs: undo sysfs when open_ctree() fails Btrfs: fix snprintf usage by send's gen_unique_name btrfs: fix defrag 32-bit integer overflow btrfs: sysfs: list the NO_HOLES feature btrfs: sysfs: don't show reserved incompat feature btrfs: call permission checks earlier in ioctls and return EPERM ...
2014-01-28Btrfs: convert printk to btrfs_ and fix BTRFS prefixFrank Holton
Convert all applicable cases of printk and pr_* to the btrfs_* macros. Fix all uses of the BTRFS prefix. Signed-off-by: Frank Holton <fholton@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: move the extent buffer radix tree into the fs_infoJosef Bacik
I need to create a fake tree to test qgroups and I don't want to have to setup a fake btree_inode. The fact is we only use the radix tree for the fs_info, so everybody else who allocates an extent_io_tree is just wasting the space anyway. This patch moves the radix tree and its lock into btrfs_fs_info so there is less stuff I have to fake to do qgroup sanity tests. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: use a bit to track if we're in the radix treeJosef Bacik
For creating a dummy in-memory btree I need to be able to use the radix tree to keep track of the buffers like normal extent buffers. With dummy buffers we skip the radix tree step, and we still want to do that for the tree mod log dummy buffers but for my test buffers we need to be able to remove them from the radix tree like normal. This will give me a way to do that. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: deal with io_tree->mapping being NULLJosef Bacik
I need to add infrastructure to allocate dummy extent buffers for running sanity tests, and to do this I need to not have to worry about having an address_mapping for an io_tree, so just fix up the places where we assume that all io_tree's have a non-NULL ->mapping. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: more efficient extent state insertionsFilipe David Borba Manana
Currently we do 2 traversals of an inode's extent_io_tree before inserting an extent state structure: 1 to see if a matching extent state already exists and 1 to do the insertion if the fist traversal didn't found such extent state. This change just combines those tree traversals into a single one. While running sysbench tests (random writes) I captured the number of elements in extent_io_tree trees for a while (into a procfs file backed by a seq_list from seq_file module) and got this histogram: Count: 9310 Range: 51.000 - 21386.000; Mean: 11785.243; Median: 18743.500; Stddev: 8923.688 Percentiles: 90th: 20985.000; 95th: 21155.000; 99th: 21369.000 51.000 - 93.933: 693 ######## 93.933 - 172.314: 938 ########## 172.314 - 315.408: 856 ######### 315.408 - 576.646: 95 # 576.646 - 6415.830: 888 ########## 6415.830 - 11713.809: 1024 ########### 11713.809 - 21386.000: 4816 ##################################################### So traversing such trees can take some significant time that can easily be avoided. Ran the following sysbench tests, 5 times each, for sequential and random writes, and got the following results: sysbench --test=fileio --file-num=1 --file-total-size=2G \ --file-test-mode=seqwr --num-threads=16 --file-block-size=65536 \ --max-requests=0 --max-time=60 --file-io-mode=sync sysbench --test=fileio --file-num=1 --file-total-size=2G \ --file-test-mode=rndwr --num-threads=16 --file-block-size=65536 \ --max-requests=0 --max-time=60 --file-io-mode=sync Before this change: sequential writes: 69.28Mb/sec (average of 5 runs) random writes: 4.14Mb/sec (average of 5 runs) After this change: sequential writes: 69.91Mb/sec (average of 5 runs) random writes: 5.69Mb/sec (average of 5 runs) Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: add missing extent state caching callsFilipe David Borba Manana
When we didn't find a matching extent state, we inserted a new one but didn't cache it in the **cached_state parameter, which makes a subsequent call do a tree lookup to get it. Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: fix extent boundary check in bio_readpage_errorFilipe David Borba Manana
Signed-off-by: Filipe David Borba Manana <fdmanana@gmail.com> Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28btrfs: remove unused variables from extent_io.cValentina Giusti
Remove unused variables: * tree from end_bio_extent_writepage, * item from extent_fiemap. Signed-off-by: Valentina Giusti <valentina.giusti@microon.de> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <clm@fb.com>