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path: root/fs/btrfs/disk-io.c
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2016-07-26btrfs: Fix slab accounting flagsNikolay Borisov
BTRFS is using a variety of slab caches to satisfy internal needs. Those slab caches are always allocated with the SLAB_RECLAIM_ACCOUNT, meaning allocations from the caches are going to be accounted as SReclaimable. At the same time btrfs is not registering any shrinkers whatsoever, thus preventing memory from the slabs to be shrunk. This means those caches are not in fact reclaimable. To fix this remove the SLAB_RECLAIM_ACCOUNT on all caches apart from the inode cache, since this one is being freed by the generic VFS super_block shrinker. Also set the transaction related caches as SLAB_TEMPORARY, to better document the lifetime of the objects (it just translates to SLAB_RECLAIM_ACCOUNT). Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26Btrfs: fix double free of fs rootLiu Bo
I got this warning while mounting a btrfs image, [ 3020.509606] ------------[ cut here ]------------ [ 3020.510107] WARNING: CPU: 3 PID: 5581 at lib/idr.c:1051 ida_remove+0xca/0x190 [ 3020.510853] ida_remove called for id=42 which is not allocated. [ 3020.511466] Modules linked in: [ 3020.511802] CPU: 3 PID: 5581 Comm: mount Not tainted 4.7.0-rc5+ #274 [ 3020.512438] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.8.2-20150714_191134- 04/01/2014 [ 3020.513385] 0000000000000286 0000000021295d86 ffff88006c66b8f0 ffffffff8182ba5a [ 3020.514153] 0000000000000000 0000000000000009 ffff88006c66b930 ffffffff810e0ed7 [ 3020.514928] 0000041b00000000 ffffffff8289a8c0 ffff88007f437880 0000000000000000 [ 3020.515717] Call Trace: [ 3020.515965] [<ffffffff8182ba5a>] dump_stack+0xc9/0x13f [ 3020.516487] [<ffffffff810e0ed7>] __warn+0x147/0x160 [ 3020.517005] [<ffffffff810e0f4f>] warn_slowpath_fmt+0x5f/0x80 [ 3020.517572] [<ffffffff8182e6ca>] ida_remove+0xca/0x190 [ 3020.518075] [<ffffffff813a2bcc>] free_anon_bdev+0x2c/0x60 [ 3020.518609] [<ffffffff81657a9f>] free_fs_root+0x13f/0x160 [ 3020.519138] [<ffffffff8165c679>] btrfs_get_fs_root+0x379/0x3d0 [ 3020.519710] [<ffffffff81e6e975>] ? __mutex_unlock_slowpath+0x155/0x2c0 [ 3020.520366] [<ffffffff816615b1>] open_ctree+0x2e91/0x3200 [ 3020.520965] [<ffffffff8161ede2>] btrfs_mount+0x1322/0x15b0 [ 3020.521536] [<ffffffff81e60e74>] ? kmemleak_alloc_percpu+0x44/0x170 [ 3020.522167] [<ffffffff8115f5e1>] ? lockdep_init_map+0x61/0x210 [ 3020.522780] [<ffffffff813a4f59>] mount_fs+0x49/0x2c0 [ 3020.523305] [<ffffffff813d840c>] vfs_kern_mount+0xac/0x1b0 [ 3020.523872] [<ffffffff8161dee1>] btrfs_mount+0x421/0x15b0 [ 3020.524402] [<ffffffff81e60e74>] ? kmemleak_alloc_percpu+0x44/0x170 [ 3020.525045] [<ffffffff8115f5e1>] ? lockdep_init_map+0x61/0x210 [ 3020.525657] [<ffffffff8115f5e1>] ? lockdep_init_map+0x61/0x210 [ 3020.526289] [<ffffffff813a4f59>] mount_fs+0x49/0x2c0 [ 3020.526803] [<ffffffff813d840c>] vfs_kern_mount+0xac/0x1b0 [ 3020.527365] [<ffffffff813dc27a>] do_mount+0x41a/0x1770 [ 3020.527899] [<ffffffff812e800d>] ? strndup_user+0x6d/0xc0 [ 3020.528447] [<ffffffff812e7f68>] ? memdup_user+0x78/0xb0 [ 3020.528987] [<ffffffff813ddad0>] SyS_mount+0x150/0x160 [ 3020.529493] [<ffffffff81e72b7c>] entry_SYSCALL_64_fastpath+0x1f/0xbd It turns out that we free fs root twice, btrfs_init_fs_root() calls free_anon_bdev(root->anon_dev) and later then btrfs_get_fs_root() cals free_fs_root which does another free_anon_bdev() and it ends up with the above warning. Instead of reset root->anon_dev to 0 after free_anon_bdev(), we can let btrfs_init_fs_root() return directly since its callers have already done the free job by calling free_fs_root(). Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-23Btrfs: Force stripesize to the value of sectorsizeChandan Rajendra
Btrfs code currently assumes stripesize to be same as sectorsize. However Btrfs-progs (until commit df05c7ed455f519e6e15e46196392e4757257305) has been setting btrfs_super_block->stripesize to a value of 4096. This commit makes sure that the value of btrfs_super_block->stripesize is a power of 2. Later, it unconditionally sets btrfs_root->stripesize to sectorsize. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-06-17Btrfs: btrfs_check_super_valid: Allow 4096 as stripesizeChandan Rajendra
Older btrfs-progs/mkfs.btrfs sets 4096 as the stripesize. Hence restricting stripesize to be equal to sectorsize would cause super block validation to return an error on architectures where PAGE_SIZE is not equal to 4096. Hence as a workaround, this commit allows stripesize to be set to 4096 bytes. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-17btrfs: avoid blocking open_ctree from cleaner_kthreadZygo Blaxell
This fixes a problem introduced in commit 2f3165ecf103599f82bf0ea254039db335fb5005 "btrfs: don't force mounts to wait for cleaner_kthread to delete one or more subvolumes". open_ctree eventually calls btrfs_replay_log which in turn calls btrfs_commit_super which tries to lock the cleaner_mutex, causing a recursive mutex deadlock during mount. Instead of playing whack-a-mole trying to keep up with all the functions that may want to lock cleaner_mutex, put all the cleaner_mutex lockers back where they were, and attack the problem more directly: keep cleaner_kthread asleep until the filesystem is mounted. When filesystems are mounted read-only and later remounted read-write, open_ctree did not set fs_info->open and neither does anything else. Set this flag in btrfs_remount so that neither btrfs_delete_unused_bgs nor cleaner_kthread get confused by the common case of "/" filesystem read-only mount followed by read-write remount. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-17Btrfs: check if extent buffer is aligned to sectorsizeLiu Bo
Thanks to fuzz testing, we can pass an invalid bytenr to extent buffer via alloc_extent_buffer(). An unaligned eb can have more pages than it should have, which ends up extent buffer's leak or some corrupted content in extent buffer. This adds a warning to let us quickly know what was happening. Now that alloc_extent_buffer() no more returns NULL, this changes its caller and callers of its caller to match with the new error handling. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-08Merge branch 'misc-fixes-4.7' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.7
2016-06-06Btrfs: self-tests: Use macros instead of constants and add missing newlineFeifei Xu
This commit replaces numerical constants with appropriate preprocessor macros. Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-06Btrfs: add more validation checks for superblockLiu Bo
This adds validation checks for super_total_bytes, super_bytes_used and super_stripesize, super_num_devices. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Reported-by: Quentin Casasnovas <quentin.casasnovas@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-02Btrfs: self-tests: Support non-4k page sizeFeifei Xu
self-tests code assumes 4k as the sectorsize and nodesize. This commit fix hardcoded 4K. Enables the self-tests code to be executed on non-4k page sized systems (e.g. ppc64). Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Feifei Xu <xufeifei@linux.vnet.ibm.com> Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-25Merge branch 'cleanups-4.7' into for-chris-4.7-20160525David Sterba
2016-05-25btrfs: fix string and comment grammatical issues and typosNicholas D Steeves
Signed-off-by: Nicholas D Steeves <nsteeves@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-16Merge branch 'cleanups-4.7' into for-chris-4.7-20160516David Sterba
2016-05-10btrfs: GFP_NOFS does not GFP_HIGHMEMDavid Sterba
Masking HIGHMEM out of NOFS does not make sense. Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-10btrfs: switch to common message helpers in open_ctree, adjust messagesDavid Sterba
Currently we lack the identification of the filesystem in most if not all mount messages, done via printk/pr_* functions. We can use the btrfs_* helpers in open_ctree, as the fs_info <-> sb link is established at the beginning of the function. The messages have been updated at the same time to be more consistent: * dropped sb->s_id, as it's not available via btrfs_* * added %d for return code where appropriate * wording changed * %Lx replaced by %llx Signed-off-by: David Sterba <dsterba@suse.com>
2016-05-06btrfs: don't force mounts to wait for cleaner_kthread to delete one or more ↵Zygo Blaxell
subvolumes During a mount, we start the cleaner kthread first because the transaction kthread wants to wake up the cleaner kthread. We start the transaction kthread next because everything in btrfs wants transactions. We do reloc recovery in the thread that was doing the original mount call once the transaction kthread is running. This means that the cleaner kthread could already be running when reloc recovery happens (e.g. if a snapshot delete was started before a crash). Relocation does not play well with the cleaner kthread, so a mutex was added in commit 5f3164813b90f7dbcb5c3ab9006906222ce471b7 "Btrfs: fix race between balance recovery and root deletion" to prevent both from being active at the same time. If the cleaner kthread is already holding the mutex by the time we get to btrfs_recover_relocation, the mount will be blocked until at least one deleted subvolume is cleaned (possibly more if the mount process doesn't get the lock right away). During this time (which could be an arbitrarily long time on a large/slow filesystem), the mount process is stuck and the filesystem is unnecessarily inaccessible. Fix this by locking cleaner_mutex before we start cleaner_kthread, and unlocking the mutex after mount no longer requires it. This ensures that the mounting process will not be blocked by the cleaner kthread. The cleaner kthread is already prepared for mutex contention and will just go to sleep until the mutex is available. Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29btrfs: sink gfp parameter to clear_extent_dirtyDavid Sterba
Callers pass GFP_NOFS. No need to pass the flags around. Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-29btrfs: sink gfp parameter to clear_extent_bitsDavid Sterba
Callers pass GFP_NOFS and GFP_KERNEL. No need to pass the flags around. Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-28btrfs: rename btrfs_std_error to btrfs_handle_fs_errorAnand Jain
btrfs_std_error() handles errors, puts FS into readonly mode (as of now). So its good idea to rename it to btrfs_handle_fs_error(). Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ edit changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
2016-04-04Merge branch 'PAGE_CACHE_SIZE-removal'Linus Torvalds
Merge PAGE_CACHE_SIZE removal patches from Kirill Shutemov: "PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. Let's stop pretending that pages in page cache are special. They are not. The first patch with most changes has been done with coccinelle. The second is manual fixups on top. The third patch removes macros definition" [ I was planning to apply this just before rc2, but then I spaced out, so here it is right _after_ rc2 instead. As Kirill suggested as a possibility, I could have decided to only merge the first two patches, and leave the old interfaces for compatibility, but I'd rather get it all done and any out-of-tree modules and patches can trivially do the converstion while still also working with older kernels, so there is little reason to try to maintain the redundant legacy model. - Linus ] * PAGE_CACHE_SIZE-removal: mm: drop PAGE_CACHE_* and page_cache_{get,release} definition mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-01Merge branch 'for-linus-4.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "This has a few fixes Dave Sterba had queued up. These are all pretty small, but since they were tested I decided against waiting for more" * 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: transaction_kthread() is not freezable btrfs: cleaner_kthread() doesn't need explicit freeze btrfs: do not write corrupted metadata blocks to disk btrfs: csum_tree_block: return proper errno value
2016-03-24Merge branch 'misc-4.6' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.6
2016-03-22btrfs: transaction_kthread() is not freezableJiri Kosina
transaction_kthread() is calling try_to_freeze(), but that's just an expeinsive no-op given the fact that the thread is not marked freezable. After removing this, disk-io.c is now independent on freezer API. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-22btrfs: cleaner_kthread() doesn't need explicit freezeJiri Kosina
cleaner_kthread() is not marked freezable, and therefore calling try_to_freeze() in its context is a pointless no-op. In addition to that, as has been clearly demonstrated by 80ad623edd2d ("Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"), it's perfectly valid / legal for cleaner_kthread() to stay scheduled out in an arbitrary place during suspend (in that particular example that was waiting for reading of extent pages), so there is no need to leave any traces of freezer in this kthread. Fixes: 80ad623edd2d ("Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()") Fixes: 696249132158 ("btrfs: clear PF_NOFREEZE in cleaner_kthread()") Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-22btrfs: do not write corrupted metadata blocks to diskAlex Lyakas
csum_dirty_buffer was issuing a warning in case the extent buffer did not look alright, but was still returning success. Let's return error in this case, and also add an additional sanity check on the extent buffer header. The caller up the chain may BUG_ON on this, for example flush_epd_write_bio will, but it is better than to have a silent metadata corruption on disk. Signed-off-by: Alex Lyakas <alex@zadarastorage.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-22btrfs: csum_tree_block: return proper errno valueAlex Lyakas
Signed-off-by: Alex Lyakas <alex@zadarastorage.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-21Merge branch 'for-linus-4.6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "We have a good sized cleanup of our internal read ahead code, and the first series of commits from Chandan to enable PAGE_SIZE > sectorsize Otherwise, it's a normal series of cleanups and fixes, with many thanks to Dave Sterba for doing most of the patch wrangling this time" * 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (82 commits) btrfs: make sure we stay inside the bvec during __btrfs_lookup_bio_sums btrfs: Fix misspellings in comments. btrfs: Print Warning only if ENOSPC_DEBUG is enabled btrfs: scrub: silence an uninitialized variable warning btrfs: move btrfs_compression_type to compression.h btrfs: rename btrfs_print_info to btrfs_print_mod_info Btrfs: Show a warning message if one of objectid reaches its highest value Documentation: btrfs: remove usage specific information btrfs: use kbasename in btrfsic_mount Btrfs: do not collect ordered extents when logging that inode exists Btrfs: fix race when checking if we can skip fsync'ing an inode Btrfs: fix listxattrs not listing all xattrs packed in the same item Btrfs: fix deadlock between direct IO reads and buffered writes Btrfs: fix extent_same allowing destination offset beyond i_size Btrfs: fix file loss on log replay after renaming a file and fsync Btrfs: fix unreplayable log after snapshot delete + parent dir fsync Btrfs: fix lockdep deadlock warning due to dev_replace btrfs: drop unused argument in btrfs_ioctl_get_supported_features btrfs: add GET_SUPPORTED_FEATURES to the control device ioctls btrfs: change max_inline default to 2048 ...
2016-03-14btrfs: Fix misspellings in comments.Adam Buchbinder
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-11btrfs: move btrfs_compression_type to compression.hAnand Jain
So that its better organized. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-26Merge branch 'cleanups-4.6' into for-chris-4.6David Sterba
2016-02-26Merge branch 'foreign/liubo/replace-lockup' into for-chris-4.6David Sterba
2016-02-26Merge branch 'foreign/zhaolei/reada' into for-chris-4.6David Sterba
2016-02-26Merge branch 'foreign/qu/norecovery-v7' into for-chris-4.6David Sterba
2016-02-23Btrfs: fix lockdep deadlock warning due to dev_replaceLiu Bo
Xfstests btrfs/011 complains about a deadlock warning, [ 1226.649039] ========================================================= [ 1226.649039] [ INFO: possible irq lock inversion dependency detected ] [ 1226.649039] 4.1.0+ #270 Not tainted [ 1226.649039] --------------------------------------------------------- [ 1226.652955] kswapd0/46 just changed the state of lock: [ 1226.652955] (&delayed_node->mutex){+.+.-.}, at: [<ffffffff81458735>] __btrfs_release_delayed_node+0x45/0x1d0 [ 1226.652955] but this lock took another, RECLAIM_FS-unsafe lock in the past: [ 1226.652955] (&fs_info->dev_replace.lock){+.+.+.} and interrupts could create inverse lock ordering between them. [ 1226.652955] other info that might help us debug this: [ 1226.652955] Chain exists of: &delayed_node->mutex --> &found->groups_sem --> &fs_info->dev_replace.lock [ 1226.652955] Possible interrupt unsafe locking scenario: [ 1226.652955] CPU0 CPU1 [ 1226.652955] ---- ---- [ 1226.652955] lock(&fs_info->dev_replace.lock); [ 1226.652955] local_irq_disable(); [ 1226.652955] lock(&delayed_node->mutex); [ 1226.652955] lock(&found->groups_sem); [ 1226.652955] <Interrupt> [ 1226.652955] lock(&delayed_node->mutex); [ 1226.652955] *** DEADLOCK *** Commit 084b6e7c7607 ("btrfs: Fix a lockdep warning when running xfstest.") tried to fix a similar one that has the exactly same warning, but with that, we still run to this. The above lock chain comes from btrfs_commit_transaction ->btrfs_run_delayed_items ... ->__btrfs_update_delayed_inode ... ->__btrfs_cow_block ... ->find_free_extent ->cache_block_group ->load_free_space_cache ->btrfs_readpages ->submit_one_bio ... ->__btrfs_map_block ->btrfs_dev_replace_lock However, with high memory pressure, tasks which hold dev_replace.lock can be interrupted by kswapd and then kswapd is intended to release memory occupied by superblock, inodes and dentries, where we may call evict_inode, and it comes to [ 1226.652955] [<ffffffff81458735>] __btrfs_release_delayed_node+0x45/0x1d0 [ 1226.652955] [<ffffffff81459e74>] btrfs_remove_delayed_node+0x24/0x30 [ 1226.652955] [<ffffffff8140c5fe>] btrfs_evict_inode+0x34e/0x700 delayed_node->mutex may be acquired in __btrfs_release_delayed_node(), and it leads to a ABBA deadlock. To fix this, we can use "blocking rwlock" used in the case of extent_buffer, but things are simpler here since we only needs read's spinlock to blocking lock. With this, btrfs/011 no more produces warnings in dmesg. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18btrfs: drop null testing before destroy functionsKinglong Mee
Cleanup. kmem_cache_destroy has support NULL argument checking, so drop the double null testing before calling it. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18btrfs: reada: limit max works countZhao Lei
Reada creates 2 works for each level of tree recursively. In case of a tree having many levels, the number of created works is 2^level_of_tree. Actually we don't need so many works in parallel, this patch limits max works to BTRFS_MAX_MIRRORS * 2. The per-fs works_counter will be also used for btrfs_reada_wait() to check is there are background workers. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18btrfs: reada: Use fs_info instead of root in __readahead_hook's argumentZhao Lei
What __readahead_hook() need exactly is fs_info, no need to convert fs_info to root in caller and convert back in __readahead_hook() Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18Merge branch 'x86/urgent' into x86/asm, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-12btrfs: Introduce new mount option to disable tree log replayQu Wenruo
Introduce a new mount option "nologreplay" to co-operate with "ro" mount option to get real readonly mount, like "norecovery" in ext* and xfs. Since the new parse_options() need to check new flags at remount time, so add a new parameter for parse_options(). Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Austin S. Hemmelgarn <ahferroin7@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-12btrfs: Introduce new mount option usebackuproot to replace recoveryQu Wenruo
Current "recovery" mount option will only try to use backup root. However the word "recovery" is too generic and may be confusing for some users. Here introduce a new and more specific mount option, "usebackuproot" to replace "recovery" mount option. "Recovery" will be kept for compatibility reason, but will be deprecated. Also, since "usebackuproot" will only affect mount behavior and after open_ctree() it has nothing to do with the filesystem, so clear the flag after mount succeeded. This provides the basis for later unified "norecovery" mount option. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ dropped usebackuproot from show_mount, added note about 'recovery' to docs ] Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-11btrfs: let callers of btrfs_alloc_root pass gfp flagsDavid Sterba
We don't need to use GFP_NOFS in all contexts, eg. during mount or for dummy root tree, but we might for the the log tree creation. Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-30x86/cpufeature: Replace the old static_cpu_has() with safe variantBorislav Petkov
So the old one didn't work properly before alternatives had run. And it was supposed to provide an optimized JMP because the assumption was that the offset it is jumping to is within a signed byte and thus a two-byte JMP. So I did an x86_64 allyesconfig build and dumped all possible sites where static_cpu_has() was used. The optimization amounted to all in all 12(!) places where static_cpu_has() had generated a 2-byte JMP. Which has saved us a whopping 36 bytes! This clearly is not worth the trouble so we can remove it. The only place where the optimization might count - in __switch_to() - we will handle differently. But that's not subject of this patch. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1453842730-28463-6-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-01-29Merge branch 'for-linus-4.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "Dave had a small collection of fixes to the new free space tree code, one of which was keeping our sysfs files more up to date with feature bits as different things get enabled (lzo, raid5/6, etc). I should have kept the sysfs stuff for rc3, since we always manage to trip over something. This time it was GFP_KERNEL from somewhere that is NOFS only. Instead of rebasing it out I've put a revert in, and we'll fix it properly for rc3. Otherwise, Filipe fixed a btrfs DIO race and Qu Wenruo fixed up a use-after-free in our tracepoints that Dave Jones reported" * 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Revert "btrfs: synchronize incompat feature bits with sysfs files" btrfs: don't use GFP_HIGHMEM for free-space-tree bitmap kzalloc btrfs: sysfs: check initialization state before updating features Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()" btrfs: async-thread: Fix a use-after-free error for trace Btrfs: fix race between fsync and lockless direct IO writes btrfs: add free space tree to the cow-only list btrfs: add free space tree to lockdep classes btrfs: tweak free space tree bitmap allocation btrfs: tests: switch to GFP_KERNEL btrfs: synchronize incompat feature bits with sysfs files btrfs: sysfs: introduce helper for syncing bits with sysfs files btrfs: sysfs: add free-space-tree bit attribute btrfs: sysfs: fix typo in compat_ro attribute definition
2016-01-27Merge branch 'dev/fst-followup' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.5
2016-01-25Revert "btrfs: clear PF_NOFREEZE in cleaner_kthread()"David Sterba
This reverts commit 696249132158014d594896df3a81390616069c5c. The cleaner thread can block freezing when there's a snapshot cleaning in progress and the other threads get suspended first. From the logs provided by Martin we're waiting for reading extent pages: kernel: PM: Syncing filesystems ... done. kernel: Freezing user space processes ... (elapsed 0.015 seconds) done. kernel: Freezing remaining freezable tasks ... kernel: Freezing of tasks failed after 20.003 seconds (1 tasks refusing to freeze, wq_busy=0): kernel: btrfs-cleaner D ffff88033dd13bc0 0 152 2 0x00000000 kernel: ffff88032ebc2e00 ffff88032e750000 ffff88032e74fa50 7fffffffffffffff kernel: ffffffff814a58df 0000000000000002 ffffea000934d580 ffffffff814a5451 kernel: 7fffffffffffffff ffffffff814a6e8f 0000000000000000 0000000000000020 kernel: Call Trace: kernel: [<ffffffff814a58df>] ? bit_wait+0x2c/0x2c kernel: [<ffffffff814a5451>] ? schedule+0x6f/0x7c kernel: [<ffffffff814a6e8f>] ? schedule_timeout+0x2f/0xd8 kernel: [<ffffffff81076f94>] ? timekeeping_get_ns+0xa/0x2e kernel: [<ffffffff81077603>] ? ktime_get+0x36/0x44 kernel: [<ffffffff814a4f6c>] ? io_schedule_timeout+0x94/0xf2 kernel: [<ffffffff814a4f6c>] ? io_schedule_timeout+0x94/0xf2 kernel: [<ffffffff814a590b>] ? bit_wait_io+0x2c/0x30 kernel: [<ffffffff814a5694>] ? __wait_on_bit+0x41/0x73 kernel: [<ffffffff8109eba8>] ? wait_on_page_bit+0x6d/0x72 kernel: [<ffffffff8105d718>] ? autoremove_wake_function+0x2a/0x2a kernel: [<ffffffff811a02d7>] ? read_extent_buffer_pages+0x1bd/0x203 kernel: [<ffffffff8117d9e9>] ? free_root_pointers+0x4c/0x4c kernel: [<ffffffff8117e831>] ? btree_read_extent_buffer_pages.constprop.57+0x5a/0xe9 kernel: [<ffffffff8117f4f3>] ? read_tree_block+0x2d/0x45 kernel: [<ffffffff8116782a>] ? read_block_for_search.isra.34+0x22a/0x26b kernel: [<ffffffff811656c3>] ? btrfs_set_path_blocking+0x1e/0x4a kernel: [<ffffffff8116919b>] ? btrfs_search_slot+0x648/0x736 kernel: [<ffffffff81170559>] ? btrfs_lookup_extent_info+0xb7/0x2c7 kernel: [<ffffffff81170ee5>] ? walk_down_proc+0x9c/0x1ae kernel: [<ffffffff81171c9d>] ? walk_down_tree+0x40/0xa4 kernel: [<ffffffff8117375f>] ? btrfs_drop_snapshot+0x2da/0x664 kernel: [<ffffffff8104ff21>] ? finish_task_switch+0x126/0x167 kernel: [<ffffffff811850f8>] ? btrfs_clean_one_deleted_snapshot+0xa6/0xb0 kernel: [<ffffffff8117eaba>] ? cleaner_kthread+0x13e/0x17b kernel: [<ffffffff8117e97c>] ? btrfs_item_end+0x33/0x33 kernel: [<ffffffff8104d256>] ? kthread+0x95/0x9d kernel: [<ffffffff8104d1c1>] ? kthread_parkme+0x16/0x16 kernel: [<ffffffff814a7b5f>] ? ret_from_fork+0x3f/0x70 kernel: [<ffffffff8104d1c1>] ? kthread_parkme+0x16/0x16 As this affects a released kernel (4.4) we need a minimal fix for stable kernels. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=108361 Reported-by: Martin Ziegler <ziegler@uni-freiburg.de> CC: stable@vger.kernel.org # 4.4 CC: Jiri Kosina <jkosina@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-01-25btrfs: add free space tree to lockdep classesDavid Sterba
Signed-off-by: David Sterba <dsterba@suse.com>
2016-01-22Merge branch 'for-linus-4.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull more btrfs updates from Chris Mason: "These are mostly fixes that we've been testing, but also we grabbed and tested a few small cleanups that had been on the list for a while. Zhao Lei's patchset also fixes some early ENOSPC buglets" * 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (21 commits) btrfs: raid56: Use raid_write_end_io for scrub btrfs: Remove unnecessary ClearPageUptodate for raid56 btrfs: use rbio->nr_pages to reduce calculation btrfs: Use unified stripe_page's index calculation btrfs: Fix calculation of rbio->dbitmap's size calculation btrfs: Fix no_space in write and rm loop btrfs: merge functions for wait snapshot creation btrfs: delete unused argument in btrfs_copy_from_user btrfs: Use direct way to determine raid56 write/recover mode btrfs: Small cleanup for get index_srcdev loop btrfs: Enhance chunk validation check btrfs: Enhance super validation check Btrfs: fix deadlock running delayed iputs at transaction commit time Btrfs: fix typo in log message when starting a balance btrfs: remove duplicate const specifier btrfs: initialize the seq counter in struct btrfs_device Btrfs: clean up an error code in btrfs_init_space_info() btrfs: fix iterator with update error in backref.c Btrfs: fix output of compression message in btrfs_parse_options() Btrfs: Initialize btrfs_root->highest_objectid when loading tree root and subvolume roots ...
2016-01-19btrfs: Enhance super validation checkQu Wenruo
Enhance btrfs_check_super_valid() function by the following points: 1) Restrict sector/node size check Not the old max/min valid check, but also check if it's a power of 2. So some bogus number like 12K node size won't pass now. 2) Super flag check For now, there is still some inconsistency between kernel and btrfs-progs super flags. And considering btrfs-progs may add new flags for super block, this check will only output warning. 3) Better root alignment check Now root bytenr is checked against sector size. 4) Move some check into btrfs_check_super_valid(). Like node size vs leaf size check, and PAGESIZE vs sectorsize check. And magic number check. Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-01-19Btrfs: fix deadlock running delayed iputs at transaction commit timeFilipe Manana
While running a stress test I ran into a deadlock when running the delayed iputs at transaction time, which produced the following report and trace: [ 886.399989] ============================================= [ 886.400871] [ INFO: possible recursive locking detected ] [ 886.401663] 4.4.0-rc6-btrfs-next-18+ #1 Not tainted [ 886.402384] --------------------------------------------- [ 886.403182] fio/8277 is trying to acquire lock: [ 886.403568] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] but task is already holding lock: [ 886.403568] (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] other info that might help us debug this: [ 886.403568] Possible unsafe locking scenario: [ 886.403568] [ 886.403568] CPU0 [ 886.403568] ---- [ 886.403568] lock(&fs_info->delayed_iput_sem); [ 886.403568] lock(&fs_info->delayed_iput_sem); [ 886.403568] [ 886.403568] *** DEADLOCK *** [ 886.403568] [ 886.403568] May be due to missing lock nesting notation [ 886.403568] [ 886.403568] 3 locks held by fio/8277: [ 886.403568] #0: (sb_writers#11){.+.+.+}, at: [<ffffffff81174c4c>] __sb_start_write+0x5f/0xb0 [ 886.403568] #1: (&sb->s_type->i_mutex_key#15){+.+.+.}, at: [<ffffffffa054620d>] btrfs_file_write_iter+0x73/0x408 [btrfs] [ 886.403568] #2: (&fs_info->delayed_iput_sem){++++..}, at: [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.403568] [ 886.403568] stack backtrace: [ 886.403568] CPU: 6 PID: 8277 Comm: fio Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 886.403568] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [ 886.403568] 0000000000000000 ffff88009f80f770 ffffffff8125d4fd ffffffff82af1fc0 [ 886.403568] ffff88009f80f830 ffffffff8108e5f9 0000000200000000 ffff88009fd92290 [ 886.403568] 0000000000000000 ffffffff82af1fc0 ffffffff829cfb01 00042b216d008804 [ 886.403568] Call Trace: [ 886.403568] [<ffffffff8125d4fd>] dump_stack+0x4e/0x79 [ 886.403568] [<ffffffff8108e5f9>] __lock_acquire+0xd42/0xf0b [ 886.403568] [<ffffffff810c22db>] ? __module_address+0xdf/0x108 [ 886.403568] [<ffffffff8108eb77>] lock_acquire+0x10d/0x194 [ 886.403568] [<ffffffff8108eb77>] ? lock_acquire+0x10d/0x194 [ 886.403568] [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffff8148556b>] down_read+0x3e/0x4d [ 886.489542] [<ffffffffa0538823>] ? btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffffa0538823>] btrfs_run_delayed_iputs+0x36/0xbf [btrfs] [ 886.489542] [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs] [ 886.489542] [<ffffffffa0521d7a>] flush_space+0x435/0x44a [btrfs] [ 886.489542] [<ffffffffa052218b>] ? reserve_metadata_bytes+0x26a/0x384 [btrfs] [ 886.489542] [<ffffffffa05221ae>] reserve_metadata_bytes+0x28d/0x384 [btrfs] [ 886.489542] [<ffffffffa052256c>] ? btrfs_block_rsv_refill+0x58/0x96 [btrfs] [ 886.489542] [<ffffffffa0522584>] btrfs_block_rsv_refill+0x70/0x96 [btrfs] [ 886.489542] [<ffffffffa053d747>] btrfs_evict_inode+0x394/0x55a [btrfs] [ 886.489542] [<ffffffff81188e31>] evict+0xa7/0x15c [ 886.489542] [<ffffffff81189878>] iput+0x1d3/0x266 [ 886.489542] [<ffffffffa053887c>] btrfs_run_delayed_iputs+0x8f/0xbf [btrfs] [ 886.489542] [<ffffffffa0533953>] btrfs_commit_transaction+0x8f5/0x96e [btrfs] [ 886.489542] [<ffffffff81085096>] ? signal_pending_state+0x31/0x31 [ 886.489542] [<ffffffffa0521191>] btrfs_alloc_data_chunk_ondemand+0x1d7/0x288 [btrfs] [ 886.489542] [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs] [ 886.489542] [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs] [ 886.489542] [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs] [ 886.489542] [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128 [ 886.489542] [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs] [ 886.489542] [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50 [ 886.489542] [<ffffffff8117279e>] __vfs_write+0x7c/0xa5 [ 886.489542] [<ffffffff81172cda>] vfs_write+0xa0/0xe4 [ 886.489542] [<ffffffff811734cc>] SyS_write+0x50/0x7e [ 886.489542] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 1081.852335] INFO: task fio:8244 blocked for more than 120 seconds. [ 1081.854348] Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 1081.857560] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1081.863227] fio D ffff880213f9bb28 0 8244 8240 0x00000000 [ 1081.868719] ffff880213f9bb28 00ffffff810fc6b0 ffffffff0000000a ffff88023ed55240 [ 1081.872499] ffff880206b5d400 ffff880213f9c000 ffff88020a4d5318 ffff880206b5d400 [ 1081.876834] ffffffff00000001 ffff880206b5d400 ffff880213f9bb40 ffffffff81482ba4 [ 1081.880782] Call Trace: [ 1081.881793] [<ffffffff81482ba4>] schedule+0x7f/0x97 [ 1081.883340] [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325 [ 1081.895525] [<ffffffff8108d48d>] ? trace_hardirqs_on_caller+0x16/0x1ab [ 1081.897419] [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20 [ 1081.899251] [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20 [ 1081.901063] [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21 [ 1081.902365] [<ffffffff814855bd>] down_write+0x43/0x57 [ 1081.903846] [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1081.906078] [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1081.908846] [<ffffffff8108d461>] ? mark_held_locks+0x56/0x6c [ 1081.910409] [<ffffffffa0521282>] btrfs_check_data_free_space+0x40/0x59 [btrfs] [ 1081.912482] [<ffffffffa05228f5>] btrfs_delalloc_reserve_space+0x1e/0x4e [btrfs] [ 1081.914597] [<ffffffffa053620a>] btrfs_direct_IO+0x10c/0x27e [btrfs] [ 1081.919037] [<ffffffff8111d9a1>] generic_file_direct_write+0xb3/0x128 [ 1081.920754] [<ffffffffa05463c3>] btrfs_file_write_iter+0x229/0x408 [btrfs] [ 1081.922496] [<ffffffff8108ae38>] ? __lock_is_held+0x38/0x50 [ 1081.923922] [<ffffffff8117279e>] __vfs_write+0x7c/0xa5 [ 1081.925275] [<ffffffff81172cda>] vfs_write+0xa0/0xe4 [ 1081.926584] [<ffffffff811734cc>] SyS_write+0x50/0x7e [ 1081.927968] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [ 1081.985293] INFO: lockdep is turned off. [ 1081.986132] INFO: task fio:8249 blocked for more than 120 seconds. [ 1081.987434] Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [ 1081.988534] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 1081.990147] fio D ffff880218febbb8 0 8249 8240 0x00000000 [ 1081.991626] ffff880218febbb8 00ffffff81486b8e ffff88020000000b ffff88023ed75240 [ 1081.993258] ffff8802120a9a00 ffff880218fec000 ffff88020a4d5318 ffff8802120a9a00 [ 1081.994850] ffffffff00000001 ffff8802120a9a00 ffff880218febbd0 ffffffff81482ba4 [ 1081.996485] Call Trace: [ 1081.997037] [<ffffffff81482ba4>] schedule+0x7f/0x97 [ 1081.998017] [<ffffffff81485eb5>] rwsem_down_write_failed+0x2d5/0x325 [ 1081.999241] [<ffffffff810852a5>] ? finish_wait+0x6d/0x76 [ 1082.000306] [<ffffffff81269723>] call_rwsem_down_write_failed+0x13/0x20 [ 1082.001533] [<ffffffff81269723>] ? call_rwsem_down_write_failed+0x13/0x20 [ 1082.002776] [<ffffffff81089fae>] ? __down_write_nested.isra.0+0x1f/0x21 [ 1082.003995] [<ffffffff814855bd>] down_write+0x43/0x57 [ 1082.005000] [<ffffffffa05211b0>] ? btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1082.007403] [<ffffffffa05211b0>] btrfs_alloc_data_chunk_ondemand+0x1f6/0x288 [btrfs] [ 1082.008988] [<ffffffffa0545064>] btrfs_fallocate+0x7c1/0xc2f [btrfs] [ 1082.010193] [<ffffffff8108a1ba>] ? percpu_down_read+0x4e/0x77 [ 1082.011280] [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0 [ 1082.012265] [<ffffffff81174c4c>] ? __sb_start_write+0x5f/0xb0 [ 1082.013021] [<ffffffff811712e4>] vfs_fallocate+0x170/0x1ff [ 1082.013738] [<ffffffff81181ebb>] ioctl_preallocate+0x89/0x9b [ 1082.014778] [<ffffffff811822d7>] do_vfs_ioctl+0x40a/0x4ea [ 1082.015778] [<ffffffff81176ea7>] ? SYSC_newfstat+0x25/0x2e [ 1082.016806] [<ffffffff8118b4de>] ? __fget_light+0x4d/0x71 [ 1082.017789] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [ 1082.018706] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f This happens because we can recursively acquire the semaphore fs_info->delayed_iput_sem when attempting to allocate space to satisfy a file write request as shown in the first trace above - when committing a transaction we acquire (down_read) the semaphore before running the delayed iputs, and when running a delayed iput() we can end up calling an inode's eviction handler, which in turn commits another transaction and attempts to acquire (down_read) again the semaphore to run more delayed iput operations. This results in a deadlock because if a task acquires multiple times a semaphore it should invoke down_read_nested() with a different lockdep class for each level of recursion. Fix this by simplifying the implementation and use a mutex instead that is acquired by the cleaner kthread before it runs the delayed iputs instead of always acquiring a semaphore before delayed references are run from anywhere. Fixes: d7c151717a1e (btrfs: Fix NO_SPACE bug caused by delayed-iput) Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-10-19 16:51:16 +0000