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2023-05-30btrfs: replace calls to btrfs_find_free_ino with btrfs_find_free_objectidNikolay Borisov
[ Upstream commit abadc1fcd72e887a8f875dabe4a07aa8c28ac8af ] The former is going away as part of the inode map removal so switch callers to btrfs_find_free_objectid. No functional changes since with INODE_MAP disabled (default) find_free_objectid was called anyway. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: 0004ff15ea26 ("btrfs: fix space cache inconsistency after error loading it from disk") Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-09-22Revert "btrfs: compression: don't try to compress if we don't have enough pages"Qu Wenruo
commit 4e9655763b82a91e4c341835bb504a2b1590f984 upstream. This reverts commit f2165627319ffd33a6217275e5690b1ab5c45763. [BUG] It's no longer possible to create compressed inline extent after commit f2165627319f ("btrfs: compression: don't try to compress if we don't have enough pages"). [CAUSE] For compression code, there are several possible reasons we have a range that needs to be compressed while it's no more than one page. - Compressed inline write The data is always smaller than one sector and the test lacks the condition to properly recognize a non-inline extent. - Compressed subpage write For the incoming subpage compressed write support, we require page alignment of the delalloc range. And for 64K page size, we can compress just one page into smaller sectors. For those reasons, the requirement for the data to be more than one page is not correct, and is already causing regression for compressed inline data writeback. The idea of skipping one page to avoid wasting CPU time could be revisited in the future. [FIX] Fix it by reverting the offending commit. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Link: https://lore.kernel.org/linux-btrfs/afa2742.c084f5d6.17b6b08dffc@tnonline.net Fixes: f2165627319f ("btrfs: compression: don't try to compress if we don't have enough pages") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-08-26btrfs: prevent rename2 from exchanging a subvol with a directory from ↵NeilBrown
different parents [ Upstream commit 3f79f6f6247c83f448c8026c3ee16d4636ef8d4f ] Cross-rename lacks a check when that would prevent exchanging a directory and subvolume from different parent subvolume. This causes data inconsistencies and is caught before commit by tree-checker, turning the filesystem to read-only. Calling the renameat2 with RENAME_EXCHANGE flags like renameat2(AT_FDCWD, namesrc, AT_FDCWD, namedest, (1 << 1)) on two paths: namesrc = dir1/subvol1/dir2 namedest = subvol2/subvol3 will cause key order problem with following write time tree-checker report: [1194842.307890] BTRFS critical (device loop1): corrupt leaf: root=5 block=27574272 slot=10 ino=258, invalid previous key objectid, have 257 expect 258 [1194842.322221] BTRFS info (device loop1): leaf 27574272 gen 8 total ptrs 11 free space 15444 owner 5 [1194842.331562] BTRFS info (device loop1): refs 2 lock_owner 0 current 26561 [1194842.338772] item 0 key (256 1 0) itemoff 16123 itemsize 160 [1194842.338793] inode generation 3 size 16 mode 40755 [1194842.338801] item 1 key (256 12 256) itemoff 16111 itemsize 12 [1194842.338809] item 2 key (256 84 2248503653) itemoff 16077 itemsize 34 [1194842.338817] dir oid 258 type 2 [1194842.338823] item 3 key (256 84 2363071922) itemoff 16043 itemsize 34 [1194842.338830] dir oid 257 type 2 [1194842.338836] item 4 key (256 96 2) itemoff 16009 itemsize 34 [1194842.338843] item 5 key (256 96 3) itemoff 15975 itemsize 34 [1194842.338852] item 6 key (257 1 0) itemoff 15815 itemsize 160 [1194842.338863] inode generation 6 size 8 mode 40755 [1194842.338869] item 7 key (257 12 256) itemoff 15801 itemsize 14 [1194842.338876] item 8 key (257 84 2505409169) itemoff 15767 itemsize 34 [1194842.338883] dir oid 256 type 2 [1194842.338888] item 9 key (257 96 2) itemoff 15733 itemsize 34 [1194842.338895] item 10 key (258 12 256) itemoff 15719 itemsize 14 [1194842.339163] BTRFS error (device loop1): block=27574272 write time tree block corruption detected [1194842.339245] ------------[ cut here ]------------ [1194842.443422] WARNING: CPU: 6 PID: 26561 at fs/btrfs/disk-io.c:449 csum_one_extent_buffer+0xed/0x100 [btrfs] [1194842.511863] CPU: 6 PID: 26561 Comm: kworker/u17:2 Not tainted 5.14.0-rc3-git+ #793 [1194842.511870] Hardware name: empty empty/S3993, BIOS PAQEX0-3 02/24/2008 [1194842.511876] Workqueue: btrfs-worker-high btrfs_work_helper [btrfs] [1194842.511976] RIP: 0010:csum_one_extent_buffer+0xed/0x100 [btrfs] [1194842.512068] RSP: 0018:ffffa2c284d77da0 EFLAGS: 00010282 [1194842.512074] RAX: 0000000000000000 RBX: 0000000000001000 RCX: ffff928867bd9978 [1194842.512078] RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff928867bd9970 [1194842.512081] RBP: ffff92876b958000 R08: 0000000000000001 R09: 00000000000c0003 [1194842.512085] R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000 [1194842.512088] R13: ffff92875f989f98 R14: 0000000000000000 R15: 0000000000000000 [1194842.512092] FS: 0000000000000000(0000) GS:ffff928867a00000(0000) knlGS:0000000000000000 [1194842.512095] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1194842.512099] CR2: 000055f5384da1f0 CR3: 0000000102fe4000 CR4: 00000000000006e0 [1194842.512103] Call Trace: [1194842.512128] ? run_one_async_free+0x10/0x10 [btrfs] [1194842.631729] btree_csum_one_bio+0x1ac/0x1d0 [btrfs] [1194842.631837] run_one_async_start+0x18/0x30 [btrfs] [1194842.631938] btrfs_work_helper+0xd5/0x1d0 [btrfs] [1194842.647482] process_one_work+0x262/0x5e0 [1194842.647520] worker_thread+0x4c/0x320 [1194842.655935] ? process_one_work+0x5e0/0x5e0 [1194842.655946] kthread+0x135/0x160 [1194842.655953] ? set_kthread_struct+0x40/0x40 [1194842.655965] ret_from_fork+0x1f/0x30 [1194842.672465] irq event stamp: 1729 [1194842.672469] hardirqs last enabled at (1735): [<ffffffffbd1104f5>] console_trylock_spinning+0x185/0x1a0 [1194842.672477] hardirqs last disabled at (1740): [<ffffffffbd1104cc>] console_trylock_spinning+0x15c/0x1a0 [1194842.672482] softirqs last enabled at (1666): [<ffffffffbdc002e1>] __do_softirq+0x2e1/0x50a [1194842.672491] softirqs last disabled at (1651): [<ffffffffbd08aab7>] __irq_exit_rcu+0xa7/0xd0 The corrupted data will not be written, and filesystem can be unmounted and mounted again (all changes since the last commit will be lost). Add the missing check for new_ino so that all non-subvolumes must reside under the same parent subvolume. There's an exception allowing to exchange two subvolumes from any parents as the directory representing a subvolume is only a logical link and does not have any other structures related to the parent subvolume, unlike files, directories etc, that are always in the inode namespace of the parent subvolume. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.7+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-07-28btrfs: compression: don't try to compress if we don't have enough pagesDavid Sterba
commit f2165627319ffd33a6217275e5690b1ab5c45763 upstream The early check if we should attempt compression does not take into account the number of input pages. It can happen that there's only one page, eg. a tail page after some ranges of the BTRFS_MAX_UNCOMPRESSED have been processed, or an isolated page that won't be converted to an inline extent. The single page would be compressed but a later check would drop it again because the result size must be at least one block shorter than the input. That can never work with just one page. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: David Sterba <dsterba@suse.com> [sudip: adjust context] Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-10btrfs: mark ordered extent and inode with error if we fail to finishJosef Bacik
commit d61bec08b904cf171835db98168f82bc338e92e4 upstream. While doing error injection testing I saw that sometimes we'd get an abort that wouldn't stop the current transaction commit from completing. This abort was coming from finish ordered IO, but at this point in the transaction commit we should have gotten an error and stopped. It turns out the abort came from finish ordered io while trying to write out the free space cache. It occurred to me that any failure inside of finish_ordered_io isn't actually raised to the person doing the writing, so we could have any number of failures in this path and think the ordered extent completed successfully and the inode was fine. Fix this by marking the ordered extent with BTRFS_ORDERED_IOERR, and marking the mapping of the inode with mapping_set_error, so any callers that simply call fdatawait will also get the error. With this we're seeing the IO error on the free space inode when we fail to do the finish_ordered_io. CC: stable@vger.kernel.org # 4.19+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-24btrfs: fix slab cache flags for free space tree bitmapDavid Sterba
commit 34e49994d0dcdb2d31d4d2908d04f4e9ce57e4d7 upstream. The free space tree bitmap slab cache is created with SLAB_RED_ZONE but that's a debugging flag and not always enabled. Also the other slabs are created with at least SLAB_MEM_SPREAD that we want as well to average the memory placement cost. Reported-by: Vlastimil Babka <vbabka@suse.cz> Fixes: 3acd48507dc4 ("btrfs: fix allocation of free space cache v1 bitmap pages") CC: stable@vger.kernel.org # 5.4+ Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01btrfs: qgroup: fix data leak caused by race between writeback and truncateQu Wenruo
[ Upstream commit fa91e4aa1716004ea8096d5185ec0451e206aea0 ] [BUG] When running tests like generic/013 on test device with btrfs quota enabled, it can normally lead to data leak, detected at unmount time: BTRFS warning (device dm-3): qgroup 0/5 has unreleased space, type 0 rsv 4096 ------------[ cut here ]------------ WARNING: CPU: 11 PID: 16386 at fs/btrfs/disk-io.c:4142 close_ctree+0x1dc/0x323 [btrfs] RIP: 0010:close_ctree+0x1dc/0x323 [btrfs] Call Trace: btrfs_put_super+0x15/0x17 [btrfs] generic_shutdown_super+0x72/0x110 kill_anon_super+0x18/0x30 btrfs_kill_super+0x17/0x30 [btrfs] deactivate_locked_super+0x3b/0xa0 deactivate_super+0x40/0x50 cleanup_mnt+0x135/0x190 __cleanup_mnt+0x12/0x20 task_work_run+0x64/0xb0 __prepare_exit_to_usermode+0x1bc/0x1c0 __syscall_return_slowpath+0x47/0x230 do_syscall_64+0x64/0xb0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ---[ end trace caf08beafeca2392 ]--- BTRFS error (device dm-3): qgroup reserved space leaked [CAUSE] In the offending case, the offending operations are: 2/6: writev f2X[269 1 0 0 0 0] [1006997,67,288] 0 2/7: truncate f2X[269 1 0 0 48 1026293] 18388 0 The following sequence of events could happen after the writev(): CPU1 (writeback) | CPU2 (truncate) ----------------------------------------------------------------- btrfs_writepages() | |- extent_write_cache_pages() | |- Got page for 1003520 | | 1003520 is Dirty, no writeback | | So (!clear_page_dirty_for_io()) | | gets called for it | |- Now page 1003520 is Clean. | | | btrfs_setattr() | | |- btrfs_setsize() | | |- truncate_setsize() | | New i_size is 18388 |- __extent_writepage() | | |- page_offset() > i_size | |- btrfs_invalidatepage() | |- Page is clean, so no qgroup | callback executed This means, the qgroup reserved data space is not properly released in btrfs_invalidatepage() as the page is Clean. [FIX] Instead of checking the dirty bit of a page, call btrfs_qgroup_free_data() unconditionally in btrfs_invalidatepage(). As qgroup rsv are completely bound to the QGROUP_RESERVED bit of io_tree, not bound to page status, thus we won't cause double freeing anyway. Fixes: 0b34c261e235 ("btrfs: qgroup: Prevent qgroup->reserved from going subzero") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26btrfs: inode: fix NULL pointer dereference if inode doesn't need compressionQu Wenruo
[ Upstream commit 1e6e238c3002ea3611465ce5f32777ddd6a40126 ] [BUG] There is a bug report of NULL pointer dereference caused in compress_file_extent(): Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Workqueue: btrfs-delalloc btrfs_delalloc_helper [btrfs] NIP [c008000006dd4d34] compress_file_range.constprop.41+0x75c/0x8a0 [btrfs] LR [c008000006dd4d1c] compress_file_range.constprop.41+0x744/0x8a0 [btrfs] Call Trace: [c000000c69093b00] [c008000006dd4d1c] compress_file_range.constprop.41+0x744/0x8a0 [btrfs] (unreliable) [c000000c69093bd0] [c008000006dd4ebc] async_cow_start+0x44/0xa0 [btrfs] [c000000c69093c10] [c008000006e14824] normal_work_helper+0xdc/0x598 [btrfs] [c000000c69093c80] [c0000000001608c0] process_one_work+0x2c0/0x5b0 [c000000c69093d10] [c000000000160c38] worker_thread+0x88/0x660 [c000000c69093db0] [c00000000016b55c] kthread+0x1ac/0x1c0 [c000000c69093e20] [c00000000000b660] ret_from_kernel_thread+0x5c/0x7c ---[ end trace f16954aa20d822f6 ]--- [CAUSE] For the following execution route of compress_file_range(), it's possible to hit NULL pointer dereference: compress_file_extent() |- pages = NULL; |- start = async_chunk->start = 0; |- end = async_chunk = 4095; |- nr_pages = 1; |- inode_need_compress() == false; <<< Possible, see later explanation | Now, we have nr_pages = 1, pages = NULL |- cont: |- ret = cow_file_range_inline(); |- if (ret <= 0) { |- for (i = 0; i < nr_pages; i++) { |- WARN_ON(pages[i]->mapping); <<< Crash To enter above call execution branch, we need the following race: Thread 1 (chattr) | Thread 2 (writeback) --------------------------+------------------------------ | btrfs_run_delalloc_range | |- inode_need_compress = true | |- cow_file_range_async() btrfs_ioctl_set_flag() | |- binode_flags |= | BTRFS_INODE_NOCOMPRESS | | compress_file_range() | |- inode_need_compress = false | |- nr_page = 1 while pages = NULL | | Then hit the crash [FIX] This patch will fix it by checking @pages before doing accessing it. This patch is only designed as a hot fix and easy to backport. More elegant fix may make btrfs only check inode_need_compress() once to avoid such race, but that would be another story. Reported-by: Luciano Chavez <chavez@us.ibm.com> Fixes: 4d3a800ebb12 ("btrfs: merge nr_pages input and output parameter in compress_pages") CC: stable@vger.kernel.org # 4.14.x: cecc8d9038d16: btrfs: Move free_pages_out label in inline extent handling branch in compress_file_range CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-26btrfs: Move free_pages_out label in inline extent handling branch in ↵Nikolay Borisov
compress_file_range [ Upstream commit cecc8d9038d164eda61fbcd72520975a554ea63e ] This label is only executed if compress_file_range fails to create an inline extent. So move its code in the semantically related inline extent handling branch. No functional changes. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-21btrfs: fix return value mixup in btrfs_get_extentPavel Machek
commit 881a3a11c2b858fe9b69ef79ac5ee9978a266dc9 upstream. btrfs_get_extent() sets variable ret, but out: error path expect error to be in variable err so the error code is lost. Fixes: 6bf9e4bd6a27 ("btrfs: inode: Verify inode mode to avoid NULL pointer dereference") CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Pavel Machek (CIP) <pavel@denx.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-21btrfs: free anon block device right after subvolume deletionQu Wenruo
commit 082b6c970f02fefd278c7833880cda29691a5f34 upstream. [BUG] When a lot of subvolumes are created, there is a user report about transaction aborted caused by slow anonymous block device reclaim: BTRFS: Transaction aborted (error -24) WARNING: CPU: 17 PID: 17041 at fs/btrfs/transaction.c:1576 create_pending_snapshot+0xbc4/0xd10 [btrfs] RIP: 0010:create_pending_snapshot+0xbc4/0xd10 [btrfs] Call Trace: create_pending_snapshots+0x82/0xa0 [btrfs] btrfs_commit_transaction+0x275/0x8c0 [btrfs] btrfs_mksubvol+0x4b9/0x500 [btrfs] btrfs_ioctl_snap_create_transid+0x174/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x11c/0x180 [btrfs] btrfs_ioctl+0x11a4/0x2da0 [btrfs] do_vfs_ioctl+0xa9/0x640 ksys_ioctl+0x67/0x90 __x64_sys_ioctl+0x1a/0x20 do_syscall_64+0x5a/0x110 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ---[ end trace 33f2f83f3d5250e9 ]--- BTRFS: error (device sda1) in create_pending_snapshot:1576: errno=-24 unknown BTRFS info (device sda1): forced readonly BTRFS warning (device sda1): Skipping commit of aborted transaction. BTRFS: error (device sda1) in cleanup_transaction:1831: errno=-24 unknown [CAUSE] The anonymous device pool is shared and its size is 1M. It's possible to hit that limit if the subvolume deletion is not fast enough and the subvolumes to be cleaned keep the ids allocated. [WORKAROUND] We can't avoid the anon device pool exhaustion but we can shorten the time the id is attached to the subvolume root once the subvolume becomes invisible to the user. Reported-by: Greed Rong <greedrong@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CA+UqX+NTrZ6boGnWHhSeZmEY5J76CTqmYjO2S+=tHJX7nb9DPw@mail.gmail.com/ CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-08-05btrfs: inode: Verify inode mode to avoid NULL pointer dereferenceQu Wenruo
[ Upstream commit 6bf9e4bd6a277840d3fe8c5d5d530a1fbd3db592 ] [BUG] When accessing a file on a crafted image, btrfs can crash in block layer: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 PGD 136501067 P4D 136501067 PUD 124519067 PMD 0 CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.0.0-rc8-default #252 RIP: 0010:end_bio_extent_readpage+0x144/0x700 Call Trace: <IRQ> blk_update_request+0x8f/0x350 blk_mq_end_request+0x1a/0x120 blk_done_softirq+0x99/0xc0 __do_softirq+0xc7/0x467 irq_exit+0xd1/0xe0 call_function_single_interrupt+0xf/0x20 </IRQ> RIP: 0010:default_idle+0x1e/0x170 [CAUSE] The crafted image has a tricky corruption, the INODE_ITEM has a different type against its parent dir: item 20 key (268 INODE_ITEM 0) itemoff 2808 itemsize 160 generation 13 transid 13 size 1048576 nbytes 1048576 block group 0 mode 121644 links 1 uid 0 gid 0 rdev 0 sequence 9 flags 0x0(none) This mode number 0120000 means it's a symlink. But the dir item think it's still a regular file: item 8 key (264 DIR_INDEX 5) itemoff 3707 itemsize 32 location key (268 INODE_ITEM 0) type FILE transid 13 data_len 0 name_len 2 name: f4 item 40 key (264 DIR_ITEM 51821248) itemoff 1573 itemsize 32 location key (268 INODE_ITEM 0) type FILE transid 13 data_len 0 name_len 2 name: f4 For symlink, we don't set BTRFS_I(inode)->io_tree.ops and leave it empty, as symlink is only designed to have inlined extent, all handled by tree block read. Thus no need to trigger btrfs_submit_bio_hook() for inline file extent. However end_bio_extent_readpage() expects tree->ops populated, as it's reading regular data extent. This causes NULL pointer dereference. [FIX] This patch fixes the problem in two ways: - Verify inode mode against its dir item when looking up inode So in btrfs_lookup_dentry() if we find inode mode mismatch with dir item, we error out so that corrupted inode will not be accessed. - Verify inode mode when getting extent mapping Only regular file should have regular or preallocated extent. If we found regular/preallocated file extent for symlink or the rest, we error out before submitting the read bio. With this fix that crafted image can be rejected gracefully: BTRFS critical (device loop0): inode mode mismatch with dir: inode mode=0121644 btrfs type=7 dir type=1 Reported-by: Yoon Jungyeon <jungyeon@gatech.edu> Link: https://bugzilla.kernel.org/show_bug.cgi?id=202763 Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-30btrfs: fix failure of RWF_NOWAIT write into prealloc extent beyond eofFilipe Manana
commit 4b1946284dd6641afdb9457101056d9e6ee6204c upstream. If we attempt to write to prealloc extent located after eof using a RWF_NOWAIT write, we always fail with -EAGAIN. We do actually check if we have an allocated extent for the write at the start of btrfs_file_write_iter() through a call to check_can_nocow(), but later when we go into the actual direct IO write path we simply return -EAGAIN if the write starts at or beyond EOF. Trivial to reproduce: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ touch /mnt/foo $ chattr +C /mnt/foo $ xfs_io -d -c "pwrite -S 0xab 0 64K" /mnt/foo wrote 65536/65536 bytes at offset 0 64 KiB, 16 ops; 0.0004 sec (135.575 MiB/sec and 34707.1584 ops/sec) $ xfs_io -c "falloc -k 64K 1M" /mnt/foo $ xfs_io -d -c "pwrite -N -V 1 -S 0xfe -b 64K 64K 64K" /mnt/foo pwrite: Resource temporarily unavailable On xfs and ext4 the write succeeds, as expected. Fix this by removing the wrong check at btrfs_direct_IO(). Fixes: edf064e7c6fec3 ("btrfs: nowait aio support") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-30btrfs: fix data block group relocation failure due to concurrent scrubFilipe Manana
commit 432cd2a10f1c10cead91fe706ff5dc52f06d642a upstream. When running relocation of a data block group while scrub is running in parallel, it is possible that the relocation will fail and abort the current transaction with an -EINVAL error: [134243.988595] BTRFS info (device sdc): found 14 extents, stage: move data extents [134243.999871] ------------[ cut here ]------------ [134244.000741] BTRFS: Transaction aborted (error -22) [134244.001692] WARNING: CPU: 0 PID: 26954 at fs/btrfs/ctree.c:1071 __btrfs_cow_block+0x6a7/0x790 [btrfs] [134244.003380] Modules linked in: btrfs blake2b_generic xor raid6_pq (...) [134244.012577] CPU: 0 PID: 26954 Comm: btrfs Tainted: G W 5.6.0-rc7-btrfs-next-58 #5 [134244.014162] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 [134244.016184] RIP: 0010:__btrfs_cow_block+0x6a7/0x790 [btrfs] [134244.017151] Code: 48 c7 c7 (...) [134244.020549] RSP: 0018:ffffa41607863888 EFLAGS: 00010286 [134244.021515] RAX: 0000000000000000 RBX: ffff9614bdfe09c8 RCX: 0000000000000000 [134244.022822] RDX: 0000000000000001 RSI: ffffffffb3d63980 RDI: 0000000000000001 [134244.024124] RBP: ffff961589e8c000 R08: 0000000000000000 R09: 0000000000000001 [134244.025424] R10: ffffffffc0ae5955 R11: 0000000000000000 R12: ffff9614bd530d08 [134244.026725] R13: ffff9614ced41b88 R14: ffff9614bdfe2a48 R15: 0000000000000000 [134244.028024] FS: 00007f29b63c08c0(0000) GS:ffff9615ba600000(0000) knlGS:0000000000000000 [134244.029491] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [134244.030560] CR2: 00007f4eb339b000 CR3: 0000000130d6e006 CR4: 00000000003606f0 [134244.031997] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [134244.033153] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [134244.034484] Call Trace: [134244.034984] btrfs_cow_block+0x12b/0x2b0 [btrfs] [134244.035859] do_relocation+0x30b/0x790 [btrfs] [134244.036681] ? do_raw_spin_unlock+0x49/0xc0 [134244.037460] ? _raw_spin_unlock+0x29/0x40 [134244.038235] relocate_tree_blocks+0x37b/0x730 [btrfs] [134244.039245] relocate_block_group+0x388/0x770 [btrfs] [134244.040228] btrfs_relocate_block_group+0x161/0x2e0 [btrfs] [134244.041323] btrfs_relocate_chunk+0x36/0x110 [btrfs] [134244.041345] btrfs_balance+0xc06/0x1860 [btrfs] [134244.043382] ? btrfs_ioctl_balance+0x27c/0x310 [btrfs] [134244.045586] btrfs_ioctl_balance+0x1ed/0x310 [btrfs] [134244.045611] btrfs_ioctl+0x1880/0x3760 [btrfs] [134244.049043] ? do_raw_spin_unlock+0x49/0xc0 [134244.049838] ? _raw_spin_unlock+0x29/0x40 [134244.050587] ? __handle_mm_fault+0x11b3/0x14b0 [134244.051417] ? ksys_ioctl+0x92/0xb0 [134244.052070] ksys_ioctl+0x92/0xb0 [134244.052701] ? trace_hardirqs_off_thunk+0x1a/0x1c [134244.053511] __x64_sys_ioctl+0x16/0x20 [134244.054206] do_syscall_64+0x5c/0x280 [134244.054891] entry_SYSCALL_64_after_hwframe+0x49/0xbe [134244.055819] RIP: 0033:0x7f29b51c9dd7 [134244.056491] Code: 00 00 00 (...) [134244.059767] RSP: 002b:00007ffcccc1dd08 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [134244.061168] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f29b51c9dd7 [134244.062474] RDX: 00007ffcccc1dda0 RSI: 00000000c4009420 RDI: 0000000000000003 [134244.063771] RBP: 0000000000000003 R08: 00005565cea4b000 R09: 0000000000000000 [134244.065032] R10: 0000000000000541 R11: 0000000000000202 R12: 00007ffcccc2060a [134244.066327] R13: 00007ffcccc1dda0 R14: 0000000000000002 R15: 00007ffcccc1dec0 [134244.067626] irq event stamp: 0 [134244.068202] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [134244.069351] hardirqs last disabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020 [134244.070909] softirqs last enabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020 [134244.072392] softirqs last disabled at (0): [<0000000000000000>] 0x0 [134244.073432] ---[ end trace bd7c03622e0b0a99 ]--- The -EINVAL error comes from the following chain of function calls: __btrfs_cow_block() <-- aborts the transaction btrfs_reloc_cow_block() replace_file_extents() get_new_location() <-- returns -EINVAL When relocating a data block group, for each allocated extent of the block group, we preallocate another extent (at prealloc_file_extent_cluster()), associated with the data relocation inode, and then dirty all its pages. These preallocated extents have, and must have, the same size that extents from the data block group being relocated have. Later before we start the relocation stage that updates pointers (bytenr field of file extent items) to point to the the new extents, we trigger writeback for the data relocation inode. The expectation is that writeback will write the pages to the previously preallocated extents, that it follows the NOCOW path. That is generally the case, however, if a scrub is running it may have turned the block group that contains those extents into RO mode, in which case writeback falls back to the COW path. However in the COW path instead of allocating exactly one extent with the expected size, the allocator may end up allocating several smaller extents due to free space fragmentation - because we tell it at cow_file_range() that the minimum allocation size can match the filesystem's sector size. This later breaks the relocation's expectation that an extent associated to a file extent item in the data relocation inode has the same size as the respective extent pointed by a file extent item in another tree - in this case the extent to which the relocation inode poins to is smaller, causing relocation.c:get_new_location() to return -EINVAL. For example, if we are relocating a data block group X that has a logical address of X and the block group has an extent allocated at the logical address X + 128KiB with a size of 64KiB: 1) At prealloc_file_extent_cluster() we allocate an extent for the data relocation inode with a size of 64KiB and associate it to the file offset 128KiB (X + 128KiB - X) of the data relocation inode. This preallocated extent was allocated at block group Z; 2) A scrub running in parallel turns block group Z into RO mode and starts scrubing its extents; 3) Relocation triggers writeback for the data relocation inode; 4) When running delalloc (btrfs_run_delalloc_range()), we try first the NOCOW path because the data relocation inode has BTRFS_INODE_PREALLOC set in its flags. However, because block group Z is in RO mode, the NOCOW path (run_delalloc_nocow()) falls back into the COW path, by calling cow_file_range(); 5) At cow_file_range(), in the first iteration of the while loop we call btrfs_reserve_extent() to allocate a 64KiB extent and pass it a minimum allocation size of 4KiB (fs_info->sectorsize). Due to free space fragmentation, btrfs_reserve_extent() ends up allocating two extents of 32KiB each, each one on a different iteration of that while loop; 6) Writeback of the data relocation inode completes; 7) Relocation proceeds and ends up at relocation.c:replace_file_extents(), with a leaf which has a file extent item that points to the data extent from block group X, that has a logical address (bytenr) of X + 128KiB and a size of 64KiB. Then it calls get_new_location(), which does a lookup in the data relocation tree for a file extent item starting at offset 128KiB (X + 128KiB - X) and belonging to the data relocation inode. It finds a corresponding file extent item, however that item points to an extent that has a size of 32KiB, which doesn't match the expected size of 64KiB, resuling in -EINVAL being returned from this function and propagated up to __btrfs_cow_block(), which aborts the current transaction. To fix this make sure that at cow_file_range() when we call the allocator we pass it a minimum allocation size corresponding the desired extent size if the inode belongs to the data relocation tree, otherwise pass it the filesystem's sector size as the minimum allocation size. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-22btrfs: fix wrong file range cleanup after an error filling dealloc rangeFilipe Manana
[ Upstream commit e2c8e92d1140754073ad3799eb6620c76bab2078 ] If an error happens while running dellaloc in COW mode for a range, we can end up calling extent_clear_unlock_delalloc() for a range that goes beyond our range's end offset by 1 byte, which affects 1 extra page. This results in clearing bits and doing page operations (such as a page unlock) outside our target range. Fix that by calling extent_clear_unlock_delalloc() with an inclusive end offset, instead of an exclusive end offset, at cow_file_range(). Fixes: a315e68f6e8b30 ("Btrfs: fix invalid attempt to free reserved space on failure to cow range") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-22btrfs: fix error handling when submitting direct I/O bioOmar Sandoval
[ Upstream commit 6d3113a193e3385c72240096fe397618ecab6e43 ] In btrfs_submit_direct_hook(), if a direct I/O write doesn't span a RAID stripe or chunk, we submit orig_bio without cloning it. In this case, we don't increment pending_bios. Then, if btrfs_submit_dio_bio() fails, we decrement pending_bios to -1, and we never complete orig_bio. Fix it by initializing pending_bios to 1 instead of incrementing later. Fixing this exposes another bug: we put orig_bio prematurely and then put it again from end_io. Fix it by not putting orig_bio. After this change, pending_bios is really more of a reference count, but I'll leave that cleanup separate to keep the fix small. Fixes: e65e15355429 ("btrfs: fix panic caused by direct IO") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-03-25btrfs: fix log context list corruption after rename whiteout errorFilipe Manana
commit 236ebc20d9afc5e9ff52f3cf3f365a91583aac10 upstream. During a rename whiteout, if btrfs_whiteout_for_rename() returns an error we can end up returning from btrfs_rename() with the log context object still in the root's log context list - this happens if 'sync_log' was set to true before we called btrfs_whiteout_for_rename() and it is dangerous because we end up with a corrupt linked list (root->log_ctxs) as the log context object was allocated on the stack. After btrfs_rename() returns, any task that is running btrfs_sync_log() concurrently can end up crashing because that linked list is traversed by btrfs_sync_log() (through btrfs_remove_all_log_ctxs()). That results in the same issue that commit e6c617102c7e4 ("Btrfs: fix log context list corruption after rename exchange operation") fixed. Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name") CC: stable@vger.kernel.org # 4.19+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-02-28btrfs: fix bytes_may_use underflow in prealloc error condtitionJosef Bacik
commit b778cf962d71a0e737923d55d0432f3bd287258e upstream. I hit the following warning while running my error injection stress testing: WARNING: CPU: 3 PID: 1453 at fs/btrfs/space-info.h:108 btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs] RIP: 0010:btrfs_free_reserved_data_space_noquota+0xfd/0x160 [btrfs] Call Trace: btrfs_free_reserved_data_space+0x4f/0x70 [btrfs] __btrfs_prealloc_file_range+0x378/0x470 [btrfs] elfcorehdr_read+0x40/0x40 ? elfcorehdr_read+0x40/0x40 ? btrfs_commit_transaction+0xca/0xa50 [btrfs] ? dput+0xb4/0x2a0 ? btrfs_log_dentry_safe+0x55/0x70 [btrfs] ? btrfs_sync_file+0x30e/0x420 [btrfs] ? do_fsync+0x38/0x70 ? __x64_sys_fdatasync+0x13/0x20 ? do_syscall_64+0x5b/0x1b0 ? entry_SYSCALL_64_after_hwframe+0x44/0xa9 This happens if we fail to insert our reserved file extent. At this point we've already converted our reservation from ->bytes_may_use to ->bytes_reserved. However once we break we will attempt to free everything from [cur_offset, end] from ->bytes_may_use, but our extent reservation will overlap part of this. Fix this problem by adding ins.offset (our extent allocation size) to cur_offset so we remove the actual remaining part from ->bytes_may_use. I validated this fix using my inject-error.py script python inject-error.py -o should_fail_bio -t cache_save_setup -t \ __btrfs_prealloc_file_range \ -t insert_reserved_file_extent.constprop.0 \ -r "-5" ./run-fsstress.sh where run-fsstress.sh simply mounts and runs fsstress on a disk. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23btrfs: fix invalid removal of root refJosef Bacik
commit d49d3287e74ffe55ae7430d1e795e5f9bf7359ea upstream. If we have the following sequence of events btrfs sub create A btrfs sub create A/B btrfs sub snap A C mkdir C/foo mv A/B C/foo rm -rf * We will end up with a transaction abort. The reason for this is because we create a root ref for B pointing to A. When we create a snapshot of C we still have B in our tree, but because the root ref points to A and not C we will make it appear to be empty. The problem happens when we move B into C. This removes the root ref for B pointing to A and adds a ref of B pointing to C. When we rmdir C we'll see that we have a ref to our root and remove the root ref, despite not actually matching our reference name. Now btrfs_del_root_ref() allowing this to work is a bug as well, however we know that this inode does not actually point to a root ref in the first place, so we shouldn't be calling btrfs_del_root_ref() in the first place and instead simply look up our dir index for this item and do the rest of the removal. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23btrfs: rework arguments of btrfs_unlink_subvolJosef Bacik
[ Upstream commit 045d3967b6920b663fc010ad414ade1b24143bd1 ] btrfs_unlink_subvol takes the name of the dentry and the root objectid based on what kind of inode this is, either a real subvolume link or a empty one that we inherited as a snapshot. We need to fix how we unlink in the case for BTRFS_EMPTY_SUBVOL_DIR_OBJECTID in the future, so rework btrfs_unlink_subvol to just take the dentry and handle getting the right objectid given the type of inode this is. There is no functional change here, simply pushing the work into btrfs_unlink_subvol() proper. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-31btrfs: do not call synchronize_srcu() in inode_tree_delJosef Bacik
commit f72ff01df9cf5db25c76674cac16605992d15467 upstream. Testing with the new fsstress uncovered a pretty nasty deadlock with lookup and snapshot deletion. Process A unlink -> final iput -> inode_tree_del -> synchronize_srcu(subvol_srcu) Process B btrfs_lookup <- srcu_read_lock() acquired here -> btrfs_iget -> find inode that has I_FREEING set -> __wait_on_freeing_inode() We're holding the srcu_read_lock() while doing the iget in order to make sure our fs root doesn't go away, and then we are waiting for the inode to finish freeing. However because the free'ing process is doing a synchronize_srcu() we deadlock. Fix this by dropping the synchronize_srcu() in inode_tree_del(). We don't need people to stop accessing the fs root at this point, we're only adding our empty root to the dead roots list. A larger much more invasive fix is forthcoming to address how we deal with fs roots, but this fixes the immediate problem. Fixes: 76dda93c6ae2 ("Btrfs: add snapshot/subvolume destroy ioctl") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-31btrfs: don't double lock the subvol_sem for rename exchangeJosef Bacik
commit 943eb3bf25f4a7b745dd799e031be276aa104d82 upstream. If we're rename exchanging two subvols we'll try to lock this lock twice, which is bad. Just lock once if either of the ino's are subvols. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17btrfs: record all roots for rename exchange on a subvolJosef Bacik
commit 3e1740993e43116b3bc71b0aad1e6872f6ccf341 upstream. Testing with the new fsstress support for subvolumes uncovered a pretty bad problem with rename exchange on subvolumes. We're modifying two different subvolumes, but we only start the transaction on one of them, so the other one is not added to the dirty root list. This is caught by btrfs_cow_block() with a warning because the root has not been updated, however if we do not modify this root again we'll end up pointing at an invalid root because the root item is never updated. Fix this by making sure we add the destination root to the trans list, the same as we do with normal renames. This fixes the corruption. Fixes: cdd1fedf8261 ("btrfs: add support for RENAME_EXCHANGE and RENAME_WHITEOUT") CC: stable@vger.kernel.org # 4.9+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-17Btrfs: fix metadata space leak on fixup worker failure to set range as delallocFilipe Manana
commit 536870071dbc4278264f59c9a2f5f447e584d139 upstream. In the fixup worker, if we fail to mark the range as delalloc in the io tree, we must release the previously reserved metadata, as well as update the outstanding extents counter for the inode, otherwise we leak metadata space. In pratice we can't return an error from btrfs_set_extent_delalloc(), which is just a wrapper around __set_extent_bit(), as for most errors __set_extent_bit() does a BUG_ON() (or panics which hits a BUG_ON() as well) and returning an -EEXIST error doesn't happen in this case since the exclusive bits parameter always has a value of 0 through this code path. Nevertheless, just fix the error handling in the fixup worker, in case one day __set_extent_bit() can return an error to this code path. Fixes: f3038ee3a3f101 ("btrfs: Handle btrfs_set_extent_delalloc failure in fixup worker") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-20Btrfs: fix log context list corruption after rename exchange operationFilipe Manana
commit e6c617102c7e4ac1398cb0b98ff1f0727755b520 upstream. During rename exchange we might have successfully log the new name in the source root's log tree, in which case we leave our log context (allocated on stack) in the root's list of log contextes. However we might fail to log the new name in the destination root, in which case we fallback to a transaction commit later and never sync the log of the source root, which causes the source root log context to remain in the list of log contextes. This later causes invalid memory accesses because the context was allocated on stack and after rename exchange finishes the stack gets reused and overwritten for other purposes. The kernel's linked list corruption detector (CONFIG_DEBUG_LIST=y) can detect this and report something like the following: [ 691.489929] ------------[ cut here ]------------ [ 691.489947] list_add corruption. prev->next should be next (ffff88819c944530), but was ffff8881c23f7be4. (prev=ffff8881c23f7a38). [ 691.489967] WARNING: CPU: 2 PID: 28933 at lib/list_debug.c:28 __list_add_valid+0x95/0xe0 (...) [ 691.489998] CPU: 2 PID: 28933 Comm: fsstress Not tainted 5.4.0-rc6-btrfs-next-62 #1 [ 691.490001] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014 [ 691.490003] RIP: 0010:__list_add_valid+0x95/0xe0 (...) [ 691.490007] RSP: 0018:ffff8881f0b3faf8 EFLAGS: 00010282 [ 691.490010] RAX: 0000000000000000 RBX: ffff88819c944530 RCX: 0000000000000000 [ 691.490011] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffffffa2c497e0 [ 691.490013] RBP: ffff8881f0b3fe68 R08: ffffed103eaa4115 R09: ffffed103eaa4114 [ 691.490015] R10: ffff88819c944000 R11: ffffed103eaa4115 R12: 7fffffffffffffff [ 691.490016] R13: ffff8881b4035610 R14: ffff8881e7b84728 R15: 1ffff1103e167f7b [ 691.490019] FS: 00007f4b25ea2e80(0000) GS:ffff8881f5500000(0000) knlGS:0000000000000000 [ 691.490021] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 691.490022] CR2: 00007fffbb2d4eec CR3: 00000001f2a4a004 CR4: 00000000003606e0 [ 691.490025] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 691.490027] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 691.490029] Call Trace: [ 691.490058] btrfs_log_inode_parent+0x667/0x2730 [btrfs] [ 691.490083] ? join_transaction+0x24a/0xce0 [btrfs] [ 691.490107] ? btrfs_end_log_trans+0x80/0x80 [btrfs] [ 691.490111] ? dget_parent+0xb8/0x460 [ 691.490116] ? lock_downgrade+0x6b0/0x6b0 [ 691.490121] ? rwlock_bug.part.0+0x90/0x90 [ 691.490127] ? do_raw_spin_unlock+0x142/0x220 [ 691.490151] btrfs_log_dentry_safe+0x65/0x90 [btrfs] [ 691.490172] btrfs_sync_file+0x9f1/0xc00 [btrfs] [ 691.490195] ? btrfs_file_write_iter+0x1800/0x1800 [btrfs] [ 691.490198] ? rcu_read_lock_any_held.part.11+0x20/0x20 [ 691.490204] ? __do_sys_newstat+0x88/0xd0 [ 691.490207] ? cp_new_stat+0x5d0/0x5d0 [ 691.490218] ? do_fsync+0x38/0x60 [ 691.490220] do_fsync+0x38/0x60 [ 691.490224] __x64_sys_fdatasync+0x32/0x40 [ 691.490228] do_syscall_64+0x9f/0x540 [ 691.490233] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 691.490235] RIP: 0033:0x7f4b253ad5f0 (...) [ 691.490239] RSP: 002b:00007fffbb2d6078 EFLAGS: 00000246 ORIG_RAX: 000000000000004b [ 691.490242] RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4b253ad5f0 [ 691.490244] RDX: 00007fffbb2d5fe0 RSI: 00007fffbb2d5fe0 RDI: 0000000000000003 [ 691.490245] RBP: 000000000000000d R08: 0000000000000001 R09: 00007fffbb2d608c [ 691.490247] R10: 00000000000002e8 R11: 0000000000000246 R12: 00000000000001f4 [ 691.490248] R13: 0000000051eb851f R14: 00007fffbb2d6120 R15: 00005635a498bda0 This started happening recently when running some test cases from fstests like btrfs/004 for example, because support for rename exchange was added last week to fsstress from fstests. So fix this by deleting the log context for the source root from the list if we have logged the new name in the source root. Reported-by: Su Yue <Damenly_Su@gmx.com> Fixes: d4682ba03ef618 ("Btrfs: sync log after logging new name") CC: stable@vger.kernel.org # 4.19+ Tested-by: Su Yue <Damenly_Su@gmx.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-06Btrfs: fix deadlock on tree root leaf when finding free extentFilipe Manana
[ Upstream commit 4222ea7100c0e37adace2790c8822758bbeee179 ] When we are writing out a free space cache, during the transaction commit phase, we can end up in a deadlock which results in a stack trace like the following: schedule+0x28/0x80 btrfs_tree_read_lock+0x8e/0x120 [btrfs] ? finish_wait+0x80/0x80 btrfs_read_lock_root_node+0x2f/0x40 [btrfs] btrfs_search_slot+0xf6/0x9f0 [btrfs] ? evict_refill_and_join+0xd0/0xd0 [btrfs] ? inode_insert5+0x119/0x190 btrfs_lookup_inode+0x3a/0xc0 [btrfs] ? kmem_cache_alloc+0x166/0x1d0 btrfs_iget+0x113/0x690 [btrfs] __lookup_free_space_inode+0xd8/0x150 [btrfs] lookup_free_space_inode+0x5b/0xb0 [btrfs] load_free_space_cache+0x7c/0x170 [btrfs] ? cache_block_group+0x72/0x3b0 [btrfs] cache_block_group+0x1b3/0x3b0 [btrfs] ? finish_wait+0x80/0x80 find_free_extent+0x799/0x1010 [btrfs] btrfs_reserve_extent+0x9b/0x180 [btrfs] btrfs_alloc_tree_block+0x1b3/0x4f0 [btrfs] __btrfs_cow_block+0x11d/0x500 [btrfs] btrfs_cow_block+0xdc/0x180 [btrfs] btrfs_search_slot+0x3bd/0x9f0 [btrfs] btrfs_lookup_inode+0x3a/0xc0 [btrfs] ? kmem_cache_alloc+0x166/0x1d0 btrfs_update_inode_item+0x46/0x100 [btrfs] cache_save_setup+0xe4/0x3a0 [btrfs] btrfs_start_dirty_block_groups+0x1be/0x480 [btrfs] btrfs_commit_transaction+0xcb/0x8b0 [btrfs] At cache_save_setup() we need to update the inode item of a block group's cache which is located in the tree root (fs_info->tree_root), which means that it may result in COWing a leaf from that tree. If that happens we need to find a free metadata extent and while looking for one, if we find a block group which was not cached yet we attempt to load its cache by calling cache_block_group(). However this function will try to load the inode of the free space cache, which requires finding the matching inode item in the tree root - if that inode item is located in the same leaf as the inode item of the space cache we are updating at cache_save_setup(), we end up in a deadlock, since we try to obtain a read lock on the same extent buffer that we previously write locked. So fix this by using the tree root's commit root when searching for a block group's free space cache inode item when we are attempting to load a free space cache. This is safe since block groups once loaded stay in memory forever, as well as their caches, so after they are first loaded we will never need to read their inode items again. For new block groups, once they are created they get their ->cached field set to BTRFS_CACHE_FINISHED meaning we will not need to read their inode item. Reported-by: Andrew Nelson <andrew.s.nelson@gmail.com> Link: https://lore.kernel.org/linux-btrfs/CAPTELenq9x5KOWuQ+fa7h1r3nsJG8vyiTH8+ifjURc_duHh2Wg@mail.gmail.com/ Fixes: 9d66e233c704 ("Btrfs: load free space cache if it exists") Tested-by: Andrew Nelson <andrew.s.nelson@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-06btrfs: qgroup: Always free PREALLOC META reserve in ↵Qu Wenruo
btrfs_delalloc_release_extents() [ Upstream commit 8702ba9396bf7bbae2ab93c94acd4bd37cfa4f09 ] [Background] Btrfs qgroup uses two types of reserved space for METADATA space, PERTRANS and PREALLOC. PERTRANS is metadata space reserved for each transaction started by btrfs_start_transaction(). While PREALLOC is for delalloc, where we reserve space before joining a transaction, and finally it will be converted to PERTRANS after the writeback is done. [Inconsistency] However there is inconsistency in how we handle PREALLOC metadata space. The most obvious one is: In btrfs_buffered_write(): btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes, true); We always free qgroup PREALLOC meta space. While in btrfs_truncate_block(): btrfs_delalloc_release_extents(BTRFS_I(inode), blocksize, (ret != 0)); We only free qgroup PREALLOC meta space when something went wrong. [The Correct Behavior] The correct behavior should be the one in btrfs_buffered_write(), we should always free PREALLOC metadata space. The reason is, the btrfs_delalloc_* mechanism works by: - Reserve metadata first, even it's not necessary In btrfs_delalloc_reserve_metadata() - Free the unused metadata space Normally in: btrfs_delalloc_release_extents() |- btrfs_inode_rsv_release() Here we do calculation on whether we should release or not. E.g. for 64K buffered write, the metadata rsv works like: /* The first page */ reserve_meta: num_bytes=calc_inode_reservations() free_meta: num_bytes=0 total: num_bytes=calc_inode_reservations() /* The first page caused one outstanding extent, thus needs metadata rsv */ /* The 2nd page */ reserve_meta: num_bytes=calc_inode_reservations() free_meta: num_bytes=calc_inode_reservations() total: not changed /* The 2nd page doesn't cause new outstanding extent, needs no new meta rsv, so we free what we have reserved */ /* The 3rd~16th pages */ reserve_meta: num_bytes=calc_inode_reservations() free_meta: num_bytes=calc_inode_reservations() total: not changed (still space for one outstanding extent) This means, if btrfs_delalloc_release_extents() determines to free some space, then those space should be freed NOW. So for qgroup, we should call btrfs_qgroup_free_meta_prealloc() other than btrfs_qgroup_convert_reserved_meta(). The good news is: - The callers are not that hot The hottest caller is in btrfs_buffered_write(), which is already fixed by commit 336a8bb8e36a ("btrfs: Fix wrong btrfs_delalloc_release_extents parameter"). Thus it's not that easy to cause false EDQUOT. - The trans commit in advance for qgroup would hide the bug Since commit f5fef4593653 ("btrfs: qgroup: Make qgroup async transaction commit more aggressive"), when btrfs qgroup metadata free space is slow, it will try to commit transaction and free the wrongly converted PERTRANS space, so it's not that easy to hit such bug. [FIX] So to fix the problem, remove the @qgroup_free parameter for btrfs_delalloc_release_extents(), and always pass true to btrfs_inode_rsv_release(). Reported-by: Filipe Manana <fdmanana@suse.com> Fixes: 43b18595d660 ("btrfs: qgroup: Use separate meta reservation type for delalloc") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-10-05btrfs: fix allocation of free space cache v1 bitmap pagesChristophe Leroy
commit 3acd48507dc43eeeb0a1fe965b8bad91cab904a7 upstream. Various notifications of type "BUG kmalloc-4096 () : Redzone overwritten" have been observed recently in various parts of the kernel. After some time, it has been made a relation with the use of BTRFS filesystem and with SLUB_DEBUG turned on. [ 22.809700] BUG kmalloc-4096 (Tainted: G W ): Redzone overwritten [ 22.810286] INFO: 0xbe1a5921-0xfbfc06cd. First byte 0x0 instead of 0xcc [ 22.810866] INFO: Allocated in __load_free_space_cache+0x588/0x780 [btrfs] age=22 cpu=0 pid=224 [ 22.811193] __slab_alloc.constprop.26+0x44/0x70 [ 22.811345] kmem_cache_alloc_trace+0xf0/0x2ec [ 22.811588] __load_free_space_cache+0x588/0x780 [btrfs] [ 22.811848] load_free_space_cache+0xf4/0x1b0 [btrfs] [ 22.812090] cache_block_group+0x1d0/0x3d0 [btrfs] [ 22.812321] find_free_extent+0x680/0x12a4 [btrfs] [ 22.812549] btrfs_reserve_extent+0xec/0x220 [btrfs] [ 22.812785] btrfs_alloc_tree_block+0x178/0x5f4 [btrfs] [ 22.813032] __btrfs_cow_block+0x150/0x5d4 [btrfs] [ 22.813262] btrfs_cow_block+0x194/0x298 [btrfs] [ 22.813484] commit_cowonly_roots+0x44/0x294 [btrfs] [ 22.813718] btrfs_commit_transaction+0x63c/0xc0c [btrfs] [ 22.813973] close_ctree+0xf8/0x2a4 [btrfs] [ 22.814107] generic_shutdown_super+0x80/0x110 [ 22.814250] kill_anon_super+0x18/0x30 [ 22.814437] btrfs_kill_super+0x18/0x90 [btrfs] [ 22.814590] INFO: Freed in proc_cgroup_show+0xc0/0x248 age=41 cpu=0 pid=83 [ 22.814841] proc_cgroup_show+0xc0/0x248 [ 22.814967] proc_single_show+0x54/0x98 [ 22.815086] seq_read+0x278/0x45c [ 22.815190] __vfs_read+0x28/0x17c [ 22.815289] vfs_read+0xa8/0x14c [ 22.815381] ksys_read+0x50/0x94 [ 22.815475] ret_from_syscall+0x0/0x38 Commit 69d2480456d1 ("btrfs: use copy_page for copying pages instead of memcpy") changed the way bitmap blocks are copied. But allthough bitmaps have the size of a page, they were allocated with kzalloc(). Most of the time, kzalloc() allocates aligned blocks of memory, so copy_page() can be used. But when some debug options like SLAB_DEBUG are activated, kzalloc() may return unaligned pointer. On powerpc, memcpy(), copy_page() and other copying functions use 'dcbz' instruction which provides an entire zeroed cacheline to avoid memory read when the intention is to overwrite a full line. Functions like memcpy() are writen to care about partial cachelines at the start and end of the destination, but copy_page() assumes it gets pages. As pages are naturally cache aligned, copy_page() doesn't care about partial lines. This means that when copy_page() is called with a misaligned pointer, a few leading bytes are zeroed. To fix it, allocate bitmaps through kmem_cache instead of using kzalloc() The cache pool is created with PAGE_SIZE alignment constraint. Reported-by: Erhard F. <erhard_f@mailbox.org> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=204371 Fixes: 69d2480456d1 ("btrfs: use copy_page for copying pages instead of memcpy") Cc: stable@vger.kernel.org # 4.19+ Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Reviewed-by: David Sterba <dsterba@suse.com> [ rename to btrfs_free_space_bitmap ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-09-16btrfs: Fix error handling in btrfs_cleanup_ordered_extentsNikolay Borisov
[ Upstream commit d1051d6ebf8ef3517a5a3cf82bba8436d190f1c2 ] Running btrfs/124 in a loop hung up on me sporadically with the following call trace: btrfs D 0 5760 5324 0x00000000 Call Trace: ? __schedule+0x243/0x800 schedule+0x33/0x90 btrfs_start_ordered_extent+0x10c/0x1b0 [btrfs] ? wait_woken+0xa0/0xa0 btrfs_wait_ordered_range+0xbb/0x100 [btrfs] btrfs_relocate_block_group+0x1ff/0x230 [btrfs] btrfs_relocate_chunk+0x49/0x100 [btrfs] btrfs_balance+0xbeb/0x1740 [btrfs] btrfs_ioctl_balance+0x2ee/0x380 [btrfs] btrfs_ioctl+0x1691/0x3110 [btrfs] ? lockdep_hardirqs_on+0xed/0x180 ? __handle_mm_fault+0x8e7/0xfb0 ? _raw_spin_unlock+0x24/0x30 ? __handle_mm_fault+0x8e7/0xfb0 ? do_vfs_ioctl+0xa5/0x6e0 ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs] do_vfs_ioctl+0xa5/0x6e0 ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe ksys_ioctl+0x3a/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x60/0x1b0 entry_SYSCALL_64_after_hwframe+0x49/0xbe This happens because during page writeback it's valid for writepage_delalloc to instantiate a delalloc range which doesn't belong to the page currently being written back. The reason this case is valid is due to find_lock_delalloc_range returning any available range after the passed delalloc_start and ignoring whether the page under writeback is within that range. In turn ordered extents (OE) are always created for the returned range from find_lock_delalloc_range. If, however, a failure occurs while OE are being created then the clean up code in btrfs_cleanup_ordered_extents will be called. Unfortunately the code in btrfs_cleanup_ordered_extents doesn't consider the case of such 'foreign' range being processed and instead it always assumes that the range OE are created for belongs to the page. This leads to the first page of such foregin range to not be cleaned up since it's deliberately missed and skipped by the current cleaning up code. Fix this by correctly checking whether the current page belongs to the range being instantiated and if so adjsut the range parameters passed for cleaning up. If it doesn't, then just clean the whole OE range directly. Fixes: 524272607e88 ("btrfs: Handle delalloc error correctly to avoid ordered extent hang") CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-09-16btrfs: Remove extent_io_ops::fill_delallocNikolay Borisov
[ Upstream commit 5eaad97af8aeff38debe7d3c69ec3a0d71f8350f ] This callback is called only from writepage_delalloc which in turn is guaranteed to be called from the data page writeout path. In the end there is no reason to have the call to this function to be indrected via the extent_io_ops structure. This patch removes the callback definition, exports the function and calls it directly. No functional changes. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ rename to btrfs_run_delalloc_range ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-31btrfs: inode: Don't compress if NODATASUM or NODATACOW setQu Wenruo
commit 42c16da6d684391db83788eb680accd84f6c2083 upstream. As btrfs(5) specified: Note If nodatacow or nodatasum are enabled, compression is disabled. If NODATASUM or NODATACOW set, we should not compress the extent. Normally NODATACOW is detected properly in run_delalloc_range() so compression won't happen for NODATACOW. However for NODATASUM we don't have any check, and it can cause compressed extent without csum pretty easily, just by: mkfs.btrfs -f $dev mount $dev $mnt -o nodatasum touch $mnt/foobar mount -o remount,datasum,compress $mnt xfs_io -f -c "pwrite 0 128K" $mnt/foobar And in fact, we have a bug report about corrupted compressed extent without proper data checksum so even RAID1 can't recover the corruption. (https://bugzilla.kernel.org/show_bug.cgi?id=199707) Running compression without proper checksum could cause more damage when corruption happens, as compressed data could make the whole extent unreadable, so there is no need to allow compression for NODATACSUM. The fix will refactor the inode compression check into two parts: - inode_can_compress() As the hard requirement, checked at btrfs_run_delalloc_range(), so no compression will happen for NODATASUM inode at all. - inode_need_compress() As the soft requirement, checked at btrfs_run_delalloc_range() and compress_file_range(). Reported-by: James Harvey <jamespharvey20@gmail.com> CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-09Btrfs: fix wrong ctime and mtime of a directory after log replayFilipe Manana
commit 5338e43abbab13791144d37fd8846847062351c6 upstream. When replaying a log that contains a new file or directory name that needs to be added to its parent directory, we end up updating the mtime and the ctime of the parent directory to the current time after we have set their values to the correct ones (set at fsync time), efectivelly losing them. Sample reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/file # fsync of the directory is optional, not needed $ xfs_io -c fsync /mnt/dir $ xfs_io -c fsync /mnt/dir/file $ stat -c %Y /mnt/dir 1557856079 <power failure> $ sleep 3 $ mount /dev/sdb /mnt $ stat -c %Y /mnt/dir 1557856082 --> should have been 1557856079, the mtime is updated to the current time when replaying the log Fix this by not updating the mtime and ctime to the current time at btrfs_add_link() when we are replaying a log tree. This could be triggered by my recent fsync fuzz tester for fstests, for which an fstests patch exists titled "fstests: generic, fsync fuzz tester with fsstress". Fixes: e02119d5a7b43 ("Btrfs: Add a write ahead tree log to optimize synchronous operations") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-02-12btrfs: use tagged writepage to mitigate livelock of snapshotEthan Lien
[ Upstream commit 3cd24c698004d2f7668e0eb9fc1f096f533c791b ] Snapshot is expected to be fast. But if there are writers steadily creating dirty pages in our subvolume, the snapshot may take a very long time to complete. To fix the problem, we use tagged writepage for snapshot flusher as we do in the generic write_cache_pages(), so we can omit pages dirtied after the snapshot command. This does not change the semantics regarding which data get to the snapshot, if there are pages being dirtied during the snapshotting operation. There's a sync called before snapshot is taken in old/new case, any IO in flight just after that may be in the snapshot but this depends on other system effects that might still sync the IO. We do a simple snapshot speed test on a Intel D-1531 box: fio --ioengine=libaio --iodepth=32 --bs=4k --rw=write --size=64G --direct=0 --thread=1 --numjobs=1 --time_based --runtime=120 --filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5; time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio original: 1m58sec patched: 6.54sec This is the best case for this patch since for a sequential write case, we omit nearly all pages dirtied after the snapshot command. For a multi writers, random write test: fio --ioengine=libaio --iodepth=32 --bs=4k --rw=randwrite --size=64G --direct=0 --thread=1 --numjobs=4 --time_based --runtime=120 --filename=/mnt/sub/testfile --name=job1 --group_reporting & sleep 5; time btrfs sub snap -r /mnt/sub /mnt/snap; killall fio original: 15.83sec patched: 10.35sec The improvement is smaller compared to the sequential write case, since we omit only half of the pages dirtied after snapshot command. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Ethan Lien <ethanlien@synology.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-26btrfs: improve error handling of btrfs_add_linkJohannes Thumshirn
[ Upstream commit 1690dd41e0cb1dade80850ed8a3eb0121b96d22f ] In the error handling block, err holds the return value of either btrfs_del_root_ref() or btrfs_del_inode_ref() but it hasn't been checked since it's introduction with commit fe66a05a0679 (Btrfs: improve error handling for btrfs_insert_dir_item callers) in 2012. If the error handling in the error handling fails, there's not much left to do and the abort either happened earlier in the callees or is necessary here. So if one of btrfs_del_root_ref() or btrfs_del_inode_ref() failed, abort the transaction, but still return the original code of the failure stored in 'ret' as this will be reported to the user. Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-01-22Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"David Sterba
commit 77b7aad195099e7c6da11e94b7fa6ef5e6fb0025 upstream. This reverts commit e73e81b6d0114d4a303205a952ab2e87c44bd279. This patch causes a few problems: - adds latency to btrfs_finish_ordered_io - as btrfs_finish_ordered_io is used for free space cache, generating more work from btrfs_btree_balance_dirty_nodelay could end up in the same workque, effectively deadlocking 12260 kworker/u96:16+btrfs-freespace-write D [<0>] balance_dirty_pages+0x6e6/0x7ad [<0>] balance_dirty_pages_ratelimited+0x6bb/0xa90 [<0>] btrfs_finish_ordered_io+0x3da/0x770 [<0>] normal_work_helper+0x1c5/0x5a0 [<0>] process_one_work+0x1ee/0x5a0 [<0>] worker_thread+0x46/0x3d0 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff Transaction commit will wait on the freespace cache: 838 btrfs-transacti D [<0>] btrfs_start_ordered_extent+0x154/0x1e0 [<0>] btrfs_wait_ordered_range+0xbd/0x110 [<0>] __btrfs_wait_cache_io+0x49/0x1a0 [<0>] btrfs_write_dirty_block_groups+0x10b/0x3b0 [<0>] commit_cowonly_roots+0x215/0x2b0 [<0>] btrfs_commit_transaction+0x37e/0x910 [<0>] transaction_kthread+0x14d/0x180 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff And then writepages ends up waiting on transaction commit: 9520 kworker/u96:13+flush-btrfs-1 D [<0>] wait_current_trans+0xac/0xe0 [<0>] start_transaction+0x21b/0x4b0 [<0>] cow_file_range_inline+0x10b/0x6b0 [<0>] cow_file_range.isra.69+0x329/0x4a0 [<0>] run_delalloc_range+0x105/0x3c0 [<0>] writepage_delalloc+0x119/0x180 [<0>] __extent_writepage+0x10c/0x390 [<0>] extent_write_cache_pages+0x26f/0x3d0 [<0>] extent_writepages+0x4f/0x80 [<0>] do_writepages+0x17/0x60 [<0>] __writeback_single_inode+0x59/0x690 [<0>] writeback_sb_inodes+0x291/0x4e0 [<0>] __writeback_inodes_wb+0x87/0xb0 [<0>] wb_writeback+0x3bb/0x500 [<0>] wb_workfn+0x40d/0x610 [<0>] process_one_work+0x1ee/0x5a0 [<0>] worker_thread+0x1e0/0x3d0 [<0>] kthread+0xf5/0x130 [<0>] ret_from_fork+0x24/0x30 [<0>] 0xffffffffffffffff Eventually, we have every process in the system waiting on balance_dirty_pages(), and nobody is able to make progress on page writeback. The original patch tried to fix an OOM condition, that happened on 4.4 but no success reproducing that on later kernels (4.19 and 4.20). This is more likely a problem in OOM itself. Link: https://lore.kernel.org/linux-btrfs/20180528054821.9092-1-ethanlien@synology.com/ Reported-by: Chris Mason <clm@fb.com> CC: stable@vger.kernel.org # 4.18+ CC: ethanlien <ethanlien@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09Btrfs: fix fsync of files with multiple hard links in new directoriesFilipe Manana
commit 41bd60676923822de1df2c50b3f9a10171f4338a upstream. The log tree has a long standing problem that when a file is fsync'ed we only check for new ancestors, created in the current transaction, by following only the hard link for which the fsync was issued. We follow the ancestors using the VFS' dget_parent() API. This means that if we create a new link for a file in a directory that is new (or in an any other new ancestor directory) and then fsync the file using an old hard link, we end up not logging the new ancestor, and on log replay that new hard link and ancestor do not exist. In some cases, involving renames, the file will not exist at all. Example: mkfs.btrfs -f /dev/sdb mount /dev/sdb /mnt mkdir /mnt/A touch /mnt/foo ln /mnt/foo /mnt/A/bar xfs_io -c fsync /mnt/foo <power failure> In this example after log replay only the hard link named 'foo' exists and directory A does not exist, which is unexpected. In other major linux filesystems, such as ext4, xfs and f2fs for example, both hard links exist and so does directory A after mounting again the filesystem. Checking if any new ancestors are new and need to be logged was added in 2009 by commit 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes"), however only for the ancestors of the hard link (dentry) for which the fsync was issued, instead of checking for all ancestors for all of the inode's hard links. So fix this by tracking the id of the last transaction where a hard link was created for an inode and then on fsync fallback to a full transaction commit when an inode has more than one hard link and at least one new hard link was created in the current transaction. This is the simplest solution since this is not a common use case (adding frequently hard links for which there's an ancestor created in the current transaction and then fsync the file). In case it ever becomes a common use case, a solution that consists of iterating the fs/subvol btree for each hard link and check if any ancestor is new, could be implemented. This solves many unexpected scenarios reported by Jayashree Mohan and Vijay Chidambaram, and for which there is a new test case for fstests under review. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") CC: stable@vger.kernel.org # 4.4+ Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Reported-by: Jayashree Mohan <jayashree2912@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-09btrfs: skip file_extent generation check for free_space_inode in ↵Lu Fengqi
run_delalloc_nocow commit 27a7ff554e8d349627a90bda275c527b7348adae upstream. The test case btrfs/001 with inode_cache mount option will encounter the following warning: WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs] CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G W O 4.20.0-rc4-custom+ #30 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs] Call Trace: ? free_extent_buffer+0x46/0x90 [btrfs] run_delalloc_nocow+0x455/0x900 [btrfs] btrfs_run_delalloc_range+0x1a7/0x360 [btrfs] writepage_delalloc+0xf9/0x150 [btrfs] __extent_writepage+0x125/0x3e0 [btrfs] extent_write_cache_pages+0x1b6/0x3e0 [btrfs] ? __wake_up_common_lock+0x63/0xc0 extent_writepages+0x50/0x80 [btrfs] do_writepages+0x41/0xd0 ? __filemap_fdatawrite_range+0x9e/0xf0 __filemap_fdatawrite_range+0xbe/0xf0 btrfs_fdatawrite_range+0x1b/0x50 [btrfs] __btrfs_write_out_cache+0x42c/0x480 [btrfs] btrfs_write_out_ino_cache+0x84/0xd0 [btrfs] btrfs_save_ino_cache+0x551/0x660 [btrfs] commit_fs_roots+0xc5/0x190 [btrfs] btrfs_commit_transaction+0x2bf/0x8d0 [btrfs] btrfs_mksubvol+0x48d/0x4d0 [btrfs] btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs] btrfs_ioctl+0x123f/0x3030 [btrfs] The file extent generation of the free space inode is equal to the last snapshot of the file root, so the inode will be passed to cow_file_rage. But the inode was created and its extents were preallocated in btrfs_save_ino_cache, there are no cow copies on disk. The preallocated extent is not yet in the extent tree, and btrfs_cross_ref_exist will ignore the -ENOENT returned by check_committed_ref, so we can directly write the inode to the disk. Fixes: 78d4295b1eee ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path") CC: stable@vger.kernel.org # 4.18+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-21Btrfs: fix cur_offset in the error case for nocowRobbie Ko
commit 506481b20e818db40b6198815904ecd2d6daee64 upstream. When the cow_file_range fails, the related resources are unlocked according to the range [start..end), so the unlock cannot be repeated in run_delalloc_nocow. In some cases (e.g. cur_offset <= end && cow_start != -1), cur_offset is not updated correctly, so move the cur_offset update before cow_file_range. kernel BUG at mm/page-writeback.c:2663! Internal error: Oops - BUG: 0 [#1] SMP CPU: 3 PID: 31525 Comm: kworker/u8:7 Tainted: P O Hardware name: Realtek_RTD1296 (DT) Workqueue: writeback wb_workfn (flush-btrfs-1) task: ffffffc076db3380 ti: ffffffc02e9ac000 task.ti: ffffffc02e9ac000 PC is at clear_page_dirty_for_io+0x1bc/0x1e8 LR is at clear_page_dirty_for_io+0x14/0x1e8 pc : [<ffffffc00033c91c>] lr : [<ffffffc00033c774>] pstate: 40000145 sp : ffffffc02e9af4f0 Process kworker/u8:7 (pid: 31525, stack limit = 0xffffffc02e9ac020) Call trace: [<ffffffc00033c91c>] clear_page_dirty_for_io+0x1bc/0x1e8 [<ffffffbffc514674>] extent_clear_unlock_delalloc+0x1e4/0x210 [btrfs] [<ffffffbffc4fb168>] run_delalloc_nocow+0x3b8/0x948 [btrfs] [<ffffffbffc4fb948>] run_delalloc_range+0x250/0x3a8 [btrfs] [<ffffffbffc514c0c>] writepage_delalloc.isra.21+0xbc/0x1d8 [btrfs] [<ffffffbffc516048>] __extent_writepage+0xe8/0x248 [btrfs] [<ffffffbffc51630c>] extent_write_cache_pages.isra.17+0x164/0x378 [btrfs] [<ffffffbffc5185a8>] extent_writepages+0x48/0x68 [btrfs] [<ffffffbffc4f5828>] btrfs_writepages+0x20/0x30 [btrfs] [<ffffffc00033d758>] do_writepages+0x30/0x88 [<ffffffc0003ba0f4>] __writeback_single_inode+0x34/0x198 [<ffffffc0003ba6c4>] writeback_sb_inodes+0x184/0x3c0 [<ffffffc0003ba96c>] __writeback_inodes_wb+0x6c/0xc0 [<ffffffc0003bac20>] wb_writeback+0x1b8/0x1c0 [<ffffffc0003bb0f0>] wb_workfn+0x150/0x250 [<ffffffc0002b0014>] process_one_work+0x1dc/0x388 [<ffffffc0002b02f0>] worker_thread+0x130/0x500 [<ffffffc0002b6344>] kthread+0x10c/0x110 [<ffffffc000284590>] ret_from_fork+0x10/0x40 Code: d503201f a9025bb5 a90363b7 f90023b9 (d4210000) CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Robbie Ko <robbieko@synology.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13Btrfs: fix use-after-free during inode evictionFilipe Manana
commit 421f0922a2cfb0c75acd9746454aaa576c711a65 upstream. At inode.c:evict_inode_truncate_pages(), when we iterate over the inode's extent states, we access an extent state record's "state" field after we unlocked the inode's io tree lock. This can lead to a use-after-free issue because after we unlock the io tree that extent state record might have been freed due to being merged into another adjacent extent state record (a previous inflight bio for a read operation finished in the meanwhile which unlocked a range in the io tree and cause a merge of extent state records, as explained in the comment before the while loop added in commit 6ca0709756710 ("Btrfs: fix hang during inode eviction due to concurrent readahead")). Fix this by keeping a copy of the extent state's flags in a local variable and using it after unlocking the io tree. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201189 Fixes: b9d0b38928e2 ("btrfs: Add handler for invalidate page") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13btrfs: only free reserved extent if we didn't insert itJosef Bacik
commit 49940bdd57779c78462da7aa5a8650b2fea8c2ff upstream. When we insert the file extent once the ordered extent completes we free the reserved extent reservation as it'll have been migrated to the bytes_used counter. However if we error out after this step we'll still clear the reserved extent reservation, resulting in a negative accounting of the reserved bytes for the block group and space info. Fix this by only doing the free if we didn't successfully insert a file extent for this extent. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-11-13Btrfs: fix null pointer dereference on compressed write path errorFilipe Manana
commit 3527a018c00e5dbada2f9d7ed5576437b6dd5cfb upstream. At inode.c:compress_file_range(), under the "free_pages_out" label, we can end up dereferencing the "pages" pointer when it has a NULL value. This case happens when "start" has a value of 0 and we fail to allocate memory for the "pages" pointer. When that happens we jump to the "cont" label and then enter the "if (start == 0)" branch where we immediately call the cow_file_range_inline() function. If that function returns 0 (success creating an inline extent) or an error (like -ENOMEM for example) we jump to the "free_pages_out" label and then access "pages[i]" leading to a NULL pointer dereference, since "nr_pages" has a value greater than zero at that point. Fix this by setting "nr_pages" to 0 when we fail to allocate memory for the "pages" pointer. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201119 Fixes: 771ed689d2cd ("Btrfs: Optimize compressed writeback and reads") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-06Merge tag 'for-4.19-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - fix for improper fsync after hardlink - fix for a corruption during file deduplication - use after free fixes - RCU warning fix - fix for buffered write to nodatacow file * tag 'for-4.19-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: Fix suspicious RCU usage warning in btrfs_debug_in_rcu btrfs: use after free in btrfs_quota_enable btrfs: btrfs_shrink_device should call commit transaction at the end btrfs: fix qgroup_free wrong num_bytes in btrfs_subvolume_reserve_metadata Btrfs: fix data corruption when deduplicating between different files Btrfs: sync log after logging new name Btrfs: fix unexpected failure of nocow buffered writes after snapshotting when low on space
2018-08-23Btrfs: sync log after logging new nameFilipe Manana
When we add a new name for an inode which was logged in the current transaction, we update the inode in the log so that its new name and ancestors are added to the log. However when we do this we do not persist the log, so the changes remain in memory only, and as a consequence, any ancestors that were created in the current transaction are updated such that future calls to btrfs_inode_in_log() return true. This leads to a subsequent fsync against such new ancestor directories returning immediately, without persisting the log, therefore after a power failure the new ancestor directories do not exist, despite fsync being called against them explicitly. Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/A $ mkdir /mnt/B $ mkdir /mnt/A/C $ touch /mnt/B/foo $ xfs_io -c "fsync" /mnt/B/foo $ ln /mnt/B/foo /mnt/A/C/foo $ xfs_io -c "fsync" /mnt/A <power failure> After the power failure, directory "A" does not exist, despite the explicit fsync on it. Instead of fixing this by changing the behaviour of the explicit fsync on directory "A" to persist the log instead of doing nothing, make the logging of the new file name (which happens when creating a hard link or renaming) persist the log. This approach not only is simpler, not requiring addition of new fields to the inode in memory structure, but also gives us the same behaviour as ext4, xfs and f2fs (possibly other filesystems too). A test case for fstests follows soon. Fixes: 12fcfd22fe5b ("Btrfs: tree logging unlink/rename fixes") Reported-by: Vijay Chidambaram <vvijay03@gmail.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-17Btrfs: fix unexpected failure of nocow buffered writes after snapshotting ↵Robbie Ko
when low on space Commit e9894fd3e3b3 ("Btrfs: fix snapshot vs nocow writting") forced nocow writes to fallback to COW, during writeback, when a snapshot is created. This resulted in writes made before creating the snapshot to unexpectedly fail with ENOSPC during writeback when success (0) was returned to user space through the write system call. The steps leading to this problem are: 1. When it's not possible to allocate data space for a write, the buffered write path checks if a NOCOW write is possible. If it is, it will not reserve space and success (0) is returned to user space. 2. Then when a snapshot is created, the root's will_be_snapshotted atomic is incremented and writeback is triggered for all inode's that belong to the root being snapshotted. Incrementing that atomic forces all previous writes to fallback to COW during writeback (running delalloc). 3. This results in the writeback for the inodes to fail and therefore setting the ENOSPC error in their mappings, so that a subsequent fsync on them will report the error to user space. So it's not a completely silent data loss (since fsync will report ENOSPC) but it's a very unexpected and undesirable behaviour, because if a clean shutdown/unmount of the filesystem happens without previous calls to fsync, it is expected to have the data present in the files after mounting the filesystem again. So fix this by adding a new atomic named snapshot_force_cow to the root structure which prevents this behaviour and works the following way: 1. It is incremented when we start to create a snapshot after triggering writeback and before waiting for writeback to finish. 2. This new atomic is now what is used by writeback (running delalloc) to decide whether we need to fallback to COW or not. Because we incremented this new atomic after triggering writeback in the snapshot creation ioctl, we ensure that all buffered writes that happened before snapshot creation will succeed and not fallback to COW (which would make them fail with ENOSPC). 3. The existing atomic, will_be_snapshotted, is kept because it is used to force new buffered writes, that start after we started snapshotting, to reserve data space even when NOCOW is possible. This makes these writes fail early with ENOSPC when there's no available space to allocate, preventing the unexpected behaviour of writeback later failing with ENOSPC due to a fallback to COW mode. Fixes: e9894fd3e3b3 ("Btrfs: fix snapshot vs nocow writting") Signed-off-by: Robbie Ko <robbieko@synology.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-13Merge tag 'for-4.19-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Mostly fixes and cleanups, nothing big, though the notable thing is the inserted/deleted lines delta -1124. User visible changes: - allow defrag on opened read-only files that have rw permissions; similar to what dedupe will allow on such files Core changes: - tree checker improvements, reported by fuzzing: * more checks for: block group items, essential trees * chunk type validation * mount time cross-checks that physical and logical chunks match * switch more error codes to EUCLEAN aka EFSCORRUPTED Fixes: - fsync corner case fixes - fix send failure when root has deleted files still open - send, fix incorrect file layout after hole punching beyond eof - fix races between mount and deice scan ioctl, found by fuzzing - fix deadlock when delayed iput is called from writeback on the same inode; rare but has been observed in practice, also removes code - fix pinned byte accounting, using the right percpu helpers; this should avoid some write IO inefficiency during low space conditions - don't remove block group that still has pinned bytes - reset on-disk device stats value after replace, otherwise this would report stale values for the new device Cleanups: - time64_t/timespec64 cleanups - remove remaining dead code in scrub handling NOCOW extents after disabling it in previous cycle - simplify fsync regarding ordered extents logic and remove all the related code - remove redundant arguments in order to reduce stack space consumption - remove support for V0 type of extents, not in use since 2.6.30 - remove several unused structure members - fewer indirect function calls by inlining some callbacks - qgroup rescan timing fixes - vfs: iget cleanups" * tag 'for-4.19-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (182 commits) btrfs: revert fs_devices state on error of btrfs_init_new_device btrfs: Exit gracefully when chunk map cannot be inserted to the tree btrfs: Introduce mount time chunk <-> dev extent mapping check btrfs: Verify that every chunk has corresponding block group at mount time btrfs: Check that each block group has corresponding chunk at mount time Btrfs: send, fix incorrect file layout after hole punching beyond eof btrfs: Use wrapper macro for rcu string to remove duplicate code btrfs: simplify btrfs_iget btrfs: lift make_bad_inode into btrfs_iget btrfs: simplify IS_ERR/PTR_ERR checks btrfs: btrfs_iget never returns an is_bad_inode inode btrfs: replace: Reset on-disk dev stats value after replace btrfs: extent-tree: Remove unused __btrfs_free_block_rsv btrfs: backref: Use ERR_CAST to return error code btrfs: Remove redundant btrfs_release_path from btrfs_unlink_subvol btrfs: Remove root parameter from btrfs_unlink_subvol btrfs: Remove fs_info from btrfs_add_root_ref btrfs: Remove fs_info from btrfs_del_root_ref btrfs: Remove fs_info from btrfs_del_root btrfs: Remove fs_info from btrfs_delete_delayed_dir_index ...
2018-08-13Merge branch 'work.mkdir' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs icache updates from Al Viro: - NFS mkdir/open_by_handle race fix - analogous solution for FUSE, replacing the one currently in mainline - new primitive to be used when discarding halfway set up inodes on failed object creation; gives sane warranties re icache lookups not returning such doomed by still not freed inodes. A bunch of filesystems switched to that animal. - Miklos' fix for last cycle regression in iget5_locked(); -stable will need a slightly different variant, unfortunately. - misc bits and pieces around things icache-related (in adfs and jfs). * 'work.mkdir' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: jfs: don't bother with make_bad_inode() in ialloc() adfs: don't put inodes into icache new helper: inode_fake_hash() vfs: don't evict uninitialized inode jfs: switch to discard_new_inode() ext2: make sure that partially set up inodes won't be returned by ext2_iget() udf: switch to discard_new_inode() ufs: switch to discard_new_inode() btrfs: switch to discard_new_inode() new primitive: discard_new_inode() kill d_instantiate_no_diralias() nfs_instantiate(): prevent multiple aliases for directory inode
2018-08-06btrfs: simplify btrfs_igetAl Viro
Don't open-code iget_failed(), don't bother with btrfs_free_path(NULL), move handling of positive return values of btrfs_lookup_inode() from btrfs_read_locked_inode() to btrfs_iget() and kill now obviously pointless ASSERT() in there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: lift make_bad_inode into btrfs_igetAl Viro
We don't need to check is_bad_inode() after the call of btrfs_read_locked_inode() - it's exactly the same as checking return value for being non-zero. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Reviewed-by: David Sterba <dsterba@suse.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Remove redundant btrfs_release_path from btrfs_unlink_subvolLu Fengqi
Although it is safe to call this on already released paths with no locks held or extent buffers, removing the redundant btrfs_release_path is reasonable. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: Remove root parameter from btrfs_unlink_subvolLu Fengqi
All callers pass the root tree of dir, we can push that down to the function itself. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>