- 14 Jul, 2017 2 commits
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David Sterba authored
We've started using cloned bios more in 4.13, there are some specifics regarding the iteration. Filipe found [1] that the raid56 iterated a cloned bio using bio_for_each_segment_all, which is incorrect. The cloned bios have wrong bi_vcnt and this could lead to silent corruptions. This patch adds assertions to all remaining bio_for_each_segment_all cases. [1] https://patchwork.kernel.org/patch/9838535/Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
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David Sterba authored
- incremental send fixes - raid56 corruption fix (cloned bio iteration)
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- 13 Jul, 2017 1 commit
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Filipe Manana authored
The recent changes to make bio cloning faster (added in the 4.13 merge window) by using the bio_clone_fast() API introduced a regression on raid5/6 modes, because cloned bios have an invalid bi_vcnt field (therefore it can not be used) and the raid5/6 code uses the bio_for_each_segment_all() API to iterate the segments of a bio, and this API uses a bio's bi_vcnt field. The issue is very simple to trigger by doing for example a direct IO write against a raid5 or raid6 filesystem and then attempting to read what we wrote before: $ mkfs.btrfs -m raid5 -d raid5 -f /dev/sdc /dev/sdd /dev/sde /dev/sdf $ mount /dev/sdc /mnt $ xfs_io -f -d -c "pwrite -S 0xab 0 1M" /mnt/foobar $ od -t x1 /mnt/foobar od: /mnt/foobar: read error: Input/output error For that example, the following is also reported in dmesg/syslog: [18274.985557] btrfs_print_data_csum_error: 18 callbacks suppressed [18274.995277] BTRFS warning (device sdf): csum failed root 5 ino 257 off 0 csum 0x98f94189 expected csum 0x94374193 mirror 1 [18274.997205] BTRFS warning (device sdf): csum failed root 5 ino 257 off 4096 csum 0x98f94189 expected csum 0x94374193 mirror 1 [18275.025221] BTRFS warning (device sdf): csum failed root 5 ino 257 off 8192 csum 0x98f94189 expected csum 0x94374193 mirror 1 [18275.047422] BTRFS warning (device sdf): csum failed root 5 ino 257 off 12288 csum 0x98f94189 expected csum 0x94374193 mirror 1 [18275.054818] BTRFS warning (device sdf): csum failed root 5 ino 257 off 4096 csum 0x98f94189 expected csum 0x94374193 mirror 1 [18275.054834] BTRFS warning (device sdf): csum failed root 5 ino 257 off 8192 csum 0x98f94189 expected csum 0x94374193 mirror 1 [18275.054943] BTRFS warning (device sdf): csum failed root 5 ino 257 off 8192 csum 0x98f94189 expected csum 0x94374193 mirror 2 [18275.055207] BTRFS warning (device sdf): csum failed root 5 ino 257 off 8192 csum 0x98f94189 expected csum 0x94374193 mirror 3 [18275.055571] BTRFS warning (device sdf): csum failed root 5 ino 257 off 0 csum 0x98f94189 expected csum 0x94374193 mirror 1 [18275.062171] BTRFS warning (device sdf): csum failed root 5 ino 257 off 12288 csum 0x98f94189 expected csum 0x94374193 mirror 1 A scrub will also fail correcting bad copies, mentioning the following in dmesg/syslog: [18276.128696] scrub_handle_errored_block: 498 callbacks suppressed [18276.129617] BTRFS warning (device sdf): checksum error at logical 2186346496 on dev /dev/sde, sector 2116608, root 5, inode 257, offset 65536, length 4096, links $ [18276.149235] btrfs_dev_stat_print_on_error: 498 callbacks suppressed [18276.157897] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 1, gen 0 [18276.206059] BTRFS warning (device sdf): checksum error at logical 2186477568 on dev /dev/sdd, sector 2116736, root 5, inode 257, offset 196608, length 4096, links$ [18276.206059] BTRFS error (device sdf): bdev /dev/sdd errs: wr 0, rd 0, flush 0, corrupt 1, gen 0 [18276.306552] BTRFS warning (device sdf): checksum error at logical 2186543104 on dev /dev/sdd, sector 2116864, root 5, inode 257, offset 262144, length 4096, links$ [18276.319152] BTRFS error (device sdf): bdev /dev/sdd errs: wr 0, rd 0, flush 0, corrupt 2, gen 0 [18276.394316] BTRFS warning (device sdf): checksum error at logical 2186739712 on dev /dev/sdf, sector 2116992, root 5, inode 257, offset 458752, length 4096, links$ [18276.396348] BTRFS error (device sdf): bdev /dev/sdf errs: wr 0, rd 0, flush 0, corrupt 1, gen 0 [18276.434127] BTRFS warning (device sdf): checksum error at logical 2186870784 on dev /dev/sde, sector 2117120, root 5, inode 257, offset 589824, length 4096, links$ [18276.434127] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 2, gen 0 [18276.500504] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186477568 on dev /dev/sdd [18276.538400] BTRFS warning (device sdf): checksum error at logical 2186481664 on dev /dev/sdd, sector 2116744, root 5, inode 257, offset 200704, length 4096, links$ [18276.540452] BTRFS error (device sdf): bdev /dev/sdd errs: wr 0, rd 0, flush 0, corrupt 3, gen 0 [18276.542012] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186481664 on dev /dev/sdd [18276.585030] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186346496 on dev /dev/sde [18276.598306] BTRFS warning (device sdf): checksum error at logical 2186412032 on dev /dev/sde, sector 2116736, root 5, inode 257, offset 131072, length 4096, links$ [18276.598310] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 3, gen 0 [18276.598582] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186350592 on dev /dev/sde [18276.603455] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 4, gen 0 [18276.638362] BTRFS warning (device sdf): checksum error at logical 2186354688 on dev /dev/sde, sector 2116624, root 5, inode 257, offset 73728, length 4096, links $ [18276.640445] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 5, gen 0 [18276.645942] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186354688 on dev /dev/sde [18276.657204] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186412032 on dev /dev/sde [18276.660563] BTRFS warning (device sdf): checksum error at logical 2186416128 on dev /dev/sde, sector 2116744, root 5, inode 257, offset 135168, length 4096, links$ [18276.664609] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 6, gen 0 [18276.664609] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186358784 on dev /dev/sde So fix this by using the bio_for_each_segment() API and setting before the bio's bi_iter field to the value of the corresponding btrfs bio container's saved iterator if we are processing a cloned bio in the raid5/6 code (the same code processes both cloned and non-cloned bios). This incorrect iteration of cloned bios was also causing some occasional BUG_ONs when running fstest btrfs/064, which have a trace like the following: [ 6674.416156] ------------[ cut here ]------------ [ 6674.416157] kernel BUG at fs/btrfs/raid56.c:1897! [ 6674.416159] invalid opcode: 0000 [#1] PREEMPT SMP [ 6674.416160] Modules linked in: dm_flakey dm_mod dax ppdev tpm_tis parport_pc tpm_tis_core evdev tpm psmouse sg i2c_piix4 pcspkr parport i2c_core serio_raw button s [ 6674.416184] CPU: 3 PID: 19236 Comm: kworker/u32:10 Not tainted 4.12.0-rc6-btrfs-next-44+ #1 [ 6674.416185] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 6674.416210] Workqueue: btrfs-endio btrfs_endio_helper [btrfs] [ 6674.416211] task: ffff880147f6c740 task.stack: ffffc90001fb8000 [ 6674.416229] RIP: 0010:__raid_recover_end_io+0x1ac/0x370 [btrfs] [ 6674.416230] RSP: 0018:ffffc90001fbbb90 EFLAGS: 00010217 [ 6674.416231] RAX: ffff8801ff4b4f00 RBX: 0000000000000002 RCX: 0000000000000001 [ 6674.416232] RDX: ffff880099b045d8 RSI: ffffffff81a5f6e0 RDI: 0000000000000004 [ 6674.416232] RBP: ffffc90001fbbbc8 R08: 0000000000000001 R09: 0000000000000001 [ 6674.416233] R10: ffffc90001fbbac8 R11: 0000000000001000 R12: 0000000000000002 [ 6674.416234] R13: ffff880099b045c0 R14: 0000000000000004 R15: ffff88012bff2000 [ 6674.416235] FS: 0000000000000000(0000) GS:ffff88023f2c0000(0000) knlGS:0000000000000000 [ 6674.416235] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6674.416236] CR2: 00007f28cf282000 CR3: 00000001000c6000 CR4: 00000000000006e0 [ 6674.416239] Call Trace: [ 6674.416259] __raid56_parity_recover+0xfc/0x16e [btrfs] [ 6674.416276] raid56_parity_recover+0x157/0x16b [btrfs] [ 6674.416293] btrfs_map_bio+0xe0/0x259 [btrfs] [ 6674.416310] btrfs_submit_bio_hook+0xbf/0x147 [btrfs] [ 6674.416327] end_bio_extent_readpage+0x27b/0x4a0 [btrfs] [ 6674.416331] bio_endio+0x17d/0x1b3 [ 6674.416346] end_workqueue_fn+0x3c/0x3f [btrfs] [ 6674.416362] btrfs_scrubparity_helper+0x1aa/0x3b8 [btrfs] [ 6674.416379] btrfs_endio_helper+0xe/0x10 [btrfs] [ 6674.416381] process_one_work+0x276/0x4b6 [ 6674.416384] worker_thread+0x1ac/0x266 [ 6674.416386] ? rescuer_thread+0x278/0x278 [ 6674.416387] kthread+0x106/0x10e [ 6674.416389] ? __list_del_entry+0x22/0x22 [ 6674.416391] ret_from_fork+0x27/0x40 [ 6674.416395] Code: 44 89 e2 be 00 10 00 00 ff 15 b0 ab ef ff eb 72 4d 89 e8 89 d9 44 89 e2 be 00 10 00 00 ff 15 a3 ab ef ff eb 5d 41 83 fc ff 74 02 <0f> 0b 49 63 97 [ 6674.416432] RIP: __raid_recover_end_io+0x1ac/0x370 [btrfs] RSP: ffffc90001fbbb90 [ 6674.416434] ---[ end trace 74d56ebe7489dd6a ]--- Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
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- 06 Jul, 2017 2 commits
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Filipe Manana authored
When doing an incremental send, while processing an extent that changed between the parent and send snapshots and that extent was an inline extent in the parent snapshot, it's possible to access a memory region beyond the end of leaf if the inline extent is very small and it is the first item in a leaf. An example scenario is described below. The send snapshot has the following leaf: leaf 33865728 items 33 free space 773 generation 46 owner 5 fs uuid ab7090d8-dafd-4fb9-9246-723b6d2e2fb7 chunk uuid 2d16478c-c704-4ab9-b574-68bff2281b1f (...) item 14 key (335 EXTENT_DATA 0) itemoff 3052 itemsize 53 generation 36 type 1 (regular) extent data disk byte 12791808 nr 4096 extent data offset 0 nr 4096 ram 4096 extent compression 0 (none) item 15 key (335 EXTENT_DATA 8192) itemoff 2999 itemsize 53 generation 36 type 1 (regular) extent data disk byte 138170368 nr 225280 extent data offset 0 nr 225280 ram 225280 extent compression 0 (none) (...) And the parent snapshot has the following leaf: leaf 31272960 items 17 free space 17 generation 31 owner 5 fs uuid ab7090d8-dafd-4fb9-9246-723b6d2e2fb7 chunk uuid 2d16478c-c704-4ab9-b574-68bff2281b1f item 0 key (335 EXTENT_DATA 0) itemoff 3951 itemsize 44 generation 31 type 0 (inline) inline extent data size 23 ram_bytes 613 compression 1 (zlib) (...) When computing the send stream, it is detected that the extent of inode 335, at file offset 0, and at fs/btrfs/send.c:is_extent_unchanged() we grab the leaf from the parent snapshot and access the inline extent item. However, before jumping to the 'out' label, we access the 'offset' and 'disk_bytenr' fields of the extent item, which should not be done for inline extents since the inlined data starts at the offset of the 'disk_bytenr' field and can be very small. For example accessing the 'offset' field of the file extent item results in the following trace: [ 599.705368] general protection fault: 0000 [#1] PREEMPT SMP [ 599.706296] Modules linked in: btrfs psmouse i2c_piix4 ppdev acpi_cpufreq serio_raw parport_pc i2c_core evdev tpm_tis tpm_tis_core sg pcspkr parport tpm button su$ [ 599.709340] CPU: 7 PID: 5283 Comm: btrfs Not tainted 4.10.0-rc8-btrfs-next-46+ #1 [ 599.709340] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 599.709340] task: ffff88023eedd040 task.stack: ffffc90006658000 [ 599.709340] RIP: 0010:read_extent_buffer+0xdb/0xf4 [btrfs] [ 599.709340] RSP: 0018:ffffc9000665ba00 EFLAGS: 00010286 [ 599.709340] RAX: db73880000000000 RBX: 0000000000000000 RCX: 0000000000000001 [ 599.709340] RDX: ffffc9000665ba60 RSI: db73880000000000 RDI: ffffc9000665ba5f [ 599.709340] RBP: ffffc9000665ba30 R08: 0000000000000001 R09: ffff88020dc5e098 [ 599.709340] R10: 0000000000001000 R11: 0000160000000000 R12: 6db6db6db6db6db7 [ 599.709340] R13: ffff880000000000 R14: 0000000000000000 R15: ffff88020dc5e088 [ 599.709340] FS: 00007f519555a8c0(0000) GS:ffff88023f3c0000(0000) knlGS:0000000000000000 [ 599.709340] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 599.709340] CR2: 00007f1411afd000 CR3: 0000000235f8e000 CR4: 00000000000006e0 [ 599.709340] Call Trace: [ 599.709340] btrfs_get_token_64+0x93/0xce [btrfs] [ 599.709340] ? printk+0x48/0x50 [ 599.709340] btrfs_get_64+0xb/0xd [btrfs] [ 599.709340] process_extent+0x3a1/0x1106 [btrfs] [ 599.709340] ? btree_read_extent_buffer_pages+0x5/0xef [btrfs] [ 599.709340] changed_cb+0xb03/0xb3d [btrfs] [ 599.709340] ? btrfs_get_token_32+0x7a/0xcc [btrfs] [ 599.709340] btrfs_compare_trees+0x432/0x53d [btrfs] [ 599.709340] ? process_extent+0x1106/0x1106 [btrfs] [ 599.709340] btrfs_ioctl_send+0x960/0xe26 [btrfs] [ 599.709340] btrfs_ioctl+0x181b/0x1fed [btrfs] [ 599.709340] ? trace_hardirqs_on_caller+0x150/0x1ac [ 599.709340] vfs_ioctl+0x21/0x38 [ 599.709340] ? vfs_ioctl+0x21/0x38 [ 599.709340] do_vfs_ioctl+0x611/0x645 [ 599.709340] ? rcu_read_unlock+0x5b/0x5d [ 599.709340] ? __fget+0x6d/0x79 [ 599.709340] SyS_ioctl+0x57/0x7b [ 599.709340] entry_SYSCALL_64_fastpath+0x18/0xad [ 599.709340] RIP: 0033:0x7f51945eec47 [ 599.709340] RSP: 002b:00007ffc21c13e98 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [ 599.709340] RAX: ffffffffffffffda RBX: ffffffff81096459 RCX: 00007f51945eec47 [ 599.709340] RDX: 00007ffc21c13f20 RSI: 0000000040489426 RDI: 0000000000000004 [ 599.709340] RBP: ffffc9000665bf98 R08: 00007f519450d700 R09: 00007f519450d700 [ 599.709340] R10: 00007f519450d9d0 R11: 0000000000000202 R12: 0000000000000046 [ 599.709340] R13: ffffc9000665bf78 R14: 0000000000000000 R15: 00007f5195574040 [ 599.709340] ? trace_hardirqs_off_caller+0x43/0xb1 [ 599.709340] Code: 29 f0 49 39 d8 4c 0f 47 c3 49 03 81 58 01 00 00 44 89 c1 4c 01 c2 4c 29 c3 48 c1 f8 03 49 0f af c4 48 c1 e0 0c 4c 01 e8 48 01 c6 <f3> a4 31 f6 4$ [ 599.709340] RIP: read_extent_buffer+0xdb/0xf4 [btrfs] RSP: ffffc9000665ba00 [ 599.762057] ---[ end trace fe00d7af61b9f49e ]--- This is because the 'offset' field starts at an offset of 37 bytes (offsetof(struct btrfs_file_extent_item, offset)), has a length of 8 bytes and therefore attemping to read it causes a 1 byte access beyond the end of the leaf, as the first item's content in a leaf is located at the tail of the leaf, the item size is 44 bytes and the offset of that field plus its length (37 + 8 = 45) goes beyond the item's size by 1 byte. So fix this by accessing the 'offset' and 'disk_bytenr' fields after jumping to the 'out' label if we are processing an inline extent. We move the reading operation of the 'disk_bytenr' field too because we have the same problem as for the 'offset' field explained above when the inline data is less then 8 bytes. The access to the 'generation' field is also moved but just for the sake of grouping access to all the fields. Fixes: e1cbfd7b ("Btrfs: send, fix file hole not being preserved due to inline extent") Cc: <stable@vger.kernel.org> # v4.12+ Signed-off-by: Filipe Manana <fdmanana@suse.com>
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Filipe Manana authored
In some scenarios an incremental send stream can contain link commands with an invalid target path. Such scenarios happen after moving some directory inode A, renaming a regular file inode B into the old name of inode A and finally creating a new hard link for inode B at directory inode A. Consider the following example scenario where this issue happens. Parent snapshot: . (ino 256) | |--- dir1/ (ino 257) | |--- dir2/ (ino 258) | |--- dir3/ (ino 259) | |--- file1 (ino 261) | |--- dir4/ (ino 262) | |--- dir5/ (ino 260) Send snapshot: . (ino 256) | |--- dir1/ (ino 257) |--- dir2/ (ino 258) | |--- dir3/ (ino 259) | |--- dir4 (ino 261) | |--- dir6/ (ino 263) |--- dir44/ (ino 262) |--- file11 (ino 261) |--- dir55/ (ino 260) When attempting to apply the corresponding incremental send stream, a link command contains an invalid target path which makes the receiver fail. The following is the verbose output of the btrfs receive command: receiving snapshot mysnap2 uuid=90076fe6-5ba6-e64a-9321-9279670ed16b (...) utimes utimes dir1 utimes dir1/dir2/dir3 utimes rename dir1/dir2/dir3/dir4 -> o262-7-0 link dir1/dir2/dir3/dir4 -> dir1/dir2/dir3/file1 link dir1/dir2/dir3/dir4/file11 -> dir1/dir2/dir3/file1 ERROR: link dir1/dir2/dir3/dir4/file11 -> dir1/dir2/dir3/file1 failed: Not a directory The following steps happen during the computation of the incremental send stream the lead to this issue: 1) When processing inode 261, we orphanize inode 262 due to a name/location collision with one of the new hard links for inode 261 (created in the second step below). 2) We create one of the 2 new hard links for inode 261, the one whose location is at "dir1/dir2/dir3/dir4". 3) We then attempt to create the other new hard link for inode 261, which has inode 262 as its parent directory. Because the path for this new hard link was computed before we started processing the new references (hard links), it reflects the old name/location of inode 262, that is, it does not account for the orphanization step that happened when we started processing the new references for inode 261, whence it is no longer valid, causing the receiver to fail. So fix this issue by recomputing the full path of new references if we ended up orphanizing other inodes which are directories. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com>
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- 29 Jun, 2017 17 commits
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Qu Wenruo authored
Commit 4751832d ("btrfs: fiemap: Cache and merge fiemap extent before submit it to user") introduced a warning to catch unemitted cached fiemap extent. However such warning doesn't take the following case into consideration: 0 4K 8K |<---- fiemap range --->| |<----------- On-disk extent ------------------>| In this case, the whole 0~8K is cached, and since it's larger than fiemap range, it break the fiemap extent emit loop. This leaves the fiemap extent cached but not emitted, and caught by the final fiemap extent sanity check, causing kernel warning. This patch removes the kernel warning and renames the sanity check to emit_last_fiemap_cache() since it's possible and valid to have cached fiemap extent. Reported-by: David Sterba <dsterba@suse.cz> Reported-by: Adam Borowski <kilobyte@angband.pl> Fixes: 4751832d ("btrfs: fiemap: Cache and merge fiemap extent ...") Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Jan Kara authored
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit set, DIR1 is expected to have SGID bit set (and owning group equal to the owning group of 'DIR0'). However when 'DIR0' also has some default ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on 'DIR1' to get cleared if user is not member of the owning group. Fix the problem by moving posix_acl_update_mode() out of __btrfs_set_acl() into btrfs_set_acl(). That way the function will not be called when inheriting ACLs which is what we want as it prevents SGID bit clearing and the mode has been properly set by posix_acl_create() anyway. Fixes: 07393101 CC: stable@vger.kernel.org CC: linux-btrfs@vger.kernel.org CC: David Sterba <dsterba@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: David Sterba <dsterba@suse.com>
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Chris Mason authored
Dave Jones hit a WARN_ON(nr < 0) in btrfs_wait_ordered_roots() with v4.12-rc6. This was because commit 70e7af24 made it possible for calc_reclaim_items_nr() to return a negative number. It's not really a bug in that commit, it just didn't go far enough down the stack to find all the possible 64->32 bit overflows. This switches calc_reclaim_items_nr() to return a u64 and changes everyone that uses the results of that math to u64 as well. Reported-by: Dave Jones <davej@codemonkey.org.uk> Fixes: 70e7af24 ("Btrfs: fix delalloc accounting leak caused by u32 overflow") Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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David Sterba authored
The commit "btrfs: scrub: inline helper scrub_setup_wr_ctx" inlined a helper but wrongly sets up the target device. Incidentally there's a local variable with the same name as a parameter in the previous function, so this got caught during runtime as crash in test btrfs/027. Reported-by: Chris Mason <clm@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Qu Wenruo authored
[BUG] For the following case, btrfs can underflow qgroup reserved space at an error path: (Page size 4K, function name without "btrfs_" prefix) Task A | Task B ---------------------------------------------------------------------- Buffered_write [0, 2K) | |- check_data_free_space() | | |- qgroup_reserve_data() | | Range aligned to page | | range [0, 4K) <<< | | 4K bytes reserved <<< | |- copy pages to page cache | | Buffered_write [2K, 4K) | |- check_data_free_space() | | |- qgroup_reserved_data() | | Range alinged to page | | range [0, 4K) | | Already reserved by A <<< | | 0 bytes reserved <<< | |- delalloc_reserve_metadata() | | And it *FAILED* (Maybe EQUOTA) | |- free_reserved_data_space() |- qgroup_free_data() Range aligned to page range [0, 4K) Freeing 4K (Special thanks to Chandan for the detailed report and analyse) [CAUSE] Above Task B is freeing reserved data range [0, 4K) which is actually reserved by Task A. And at writeback time, page dirty by Task A will go through writeback routine, which will free 4K reserved data space at file extent insert time, causing the qgroup underflow. [FIX] For btrfs_qgroup_free_data(), add @reserved parameter to only free data ranges reserved by previous btrfs_qgroup_reserve_data(). So in above case, Task B will try to free 0 byte, so no underflow. Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Qu Wenruo authored
Introduce a new parameter, struct extent_changeset for btrfs_qgroup_reserved_data() and its callers. Such extent_changeset was used in btrfs_qgroup_reserve_data() to record which range it reserved in current reserve, so it can free it in error paths. The reason we need to export it to callers is, at buffered write error path, without knowing what exactly which range we reserved in current allocation, we can free space which is not reserved by us. This will lead to qgroup reserved space underflow. Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Qu Wenruo authored
btrfs: qgroup: Fix qgroup reserved space underflow caused by buffered write and quotas being enabled [BUG] Under the following case, we can underflow qgroup reserved space. Task A | Task B --------------------------------------------------------------- Quota disabled | Buffered write | |- btrfs_check_data_free_space() | | *NO* qgroup space is reserved | | since quota is *DISABLED* | |- All pages are copied to page | cache | | Enable quota | Quota scan finished | | Sync_fs | |- run_delalloc_range | |- Write pages | |- btrfs_finish_ordered_io | |- insert_reserved_file_extent | |- btrfs_qgroup_release_data() | Since no qgroup space is reserved in Task A, we underflow qgroup reserved space This can be detected by fstest btrfs/104. [CAUSE] In insert_reserved_file_extent() we tell qgroup to release the @ram_bytes size of qgroup reserved_space in all cases. And btrfs_qgroup_release_data() will check if quotas are enabled. However in the above case, the buffered write happens before quota is enabled, so we don't have the reserved space for that range. [FIX] In insert_reserved_file_extent(), we tell qgroup to release the acctual byte number it released. In the above case, since we don't have the reserved space, we tell qgroups to release 0 byte, so the problem can be fixed. And thanks to the @reserved parameter introduced by the qgroup rework, and previous patch to return released bytes, the fix can be as small as 10 lines. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ changelog updates ] Signed-off-by: David Sterba <dsterba@suse.com>
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Qu Wenruo authored
btrfs_qgroup_release/free_data() only returns 0 or a negative error number (ENOMEM is the only possible error). This is normally good enough, but sometimes we need the exact byte count it freed/released. Change it to return actually released/freed bytenr number instead of 0 for success. And slightly modify related extent_changeset structure, since in btrfs one no-hole data extent won't be larger than 128M, so "unsigned int" is large enough for the use case. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Qu Wenruo authored
Quite a lot of qgroup corruption happens due to wrong time of calling btrfs_qgroup_prepare_account_extents(). Since the safest time is to call it just before btrfs_qgroup_account_extents(), there is no need to separate these 2 functions. Merging them will make code cleaner and less bug prone. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ changelog and comment adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
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Qu Wenruo authored
Modify btrfs_qgroup_account_extent() to exit quicker for non-fs extents. The quick exit condition is: 1) The extent belongs to a non-fs tree Only fs-tree extents can affect qgroup numbers and is the only case where extent can be shared between different trees. Although strictly speaking extent in data-reloc or tree-reloc tree can be shared, data/tree-reloc root won't appear in the result of btrfs_find_all_roots(), so we can ignore such case. So we can check the first root in old_roots/new_roots ulist. - if we find the 1st root is a not a fs/subvol root, then we can skip the extent - if we find the 1st root is a fs/subvol root, then we must continue calculation OR 2) both 'nr_old_roots' and 'nr_new_roots' are 0 This means either such extent got allocated then freed in current transaction or it's a new reloc tree extent, whose nr_new_roots is 0. Either way it won't affect qgroup accounting and can be skipped safely. Such quick exit can make trace output more quite and less confusing: (example with fs uuid and time stamp removed) Before: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 btrfs_qgroup_account_extent: bytenr=29556736 num_bytes=16384 nr_old_roots=0 nr_new_roots=1 ------ Extent tree block will trigger btrfs_qgroup_account_extent() trace point while no qgroup number is changed, as extent tree won't affect qgroup accounting. After: ------ add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0 ------ Now such unrelated extent won't trigger btrfs_qgroup_account_extent() trace point, making the trace less noisy. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> [ changelog and comment adjustments ] Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
The total_bytes_pinned counter is completely broken when accounting delayed refs: - If two drops for the same extent are merged, we will decrement total_bytes_pinned twice but only increment it once. - If an add is merged into a drop or vice versa, we will decrement the total_bytes_pinned counter but never increment it. - If multiple references to an extent are dropped, we will account it multiple times, potentially vastly over-estimating the number of bytes that will be freed by a commit and doing unnecessary work when we're close to ENOSPC. The last issue is relatively minor, but the first two make the total_bytes_pinned counter leak or underflow very often. These accounting issues were introduced in b150a4f1 ("Btrfs: use a percpu to keep track of possibly pinned bytes"), but they were papered over by zeroing out the counter on every commit until d288db5d ("Btrfs: fix race of using total_bytes_pinned"). We need to make sure that an extent is accounted as pinned exactly once if and only if we will drop references to it when when the transaction is committed. Ideally we would only add to total_bytes_pinned when the *last* reference is dropped, but this information isn't readily available for data extents. Again, this over-estimation can lead to extra commits when we're close to ENOSPC, but it's not as bad as before. The fix implemented here is to increment total_bytes_pinned when the total refmod count for an extent goes negative and decrement it if the refmod count goes back to non-negative or after we've run all of the delayed refs for that extent. Signed-off-by: Omar Sandoval <osandov@fb.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
We need this to decide when to account pinned bytes. Signed-off-by: Omar Sandoval <osandov@fb.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
Currently, we only increment total_bytes_pinned in btrfs_free_tree_block() when dropping the last reference on the block. However, when the delayed ref is run later, we will decrement total_bytes_pinned regardless of whether it was the last reference or not. This causes the counter to underflow when the reference we dropped was not the last reference. Fix it by incrementing the counter unconditionally, which is what btrfs_free_extent() does. This makes total_bytes_pinned an overestimate when references to shared extents are dropped, but in the worst case this will just make us try to commit the transaction to try to free up space and find we didn't free enough. Signed-off-by: Omar Sandoval <osandov@fb.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
The extents marked in pin_down_extent() will be unpinned later in unpin_extent_range(), which decrements total_bytes_pinned. pin_down_extent() must increment the counter to avoid underflowing it. Also adjust btrfs_free_tree_block() to avoid accounting for the same extent twice. Signed-off-by: Omar Sandoval <osandov@fb.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
The value of flags is one of DATA/METADATA/SYSTEM, they must exist at when add_pinned_bytes is called. Signed-off-by: Omar Sandoval <osandov@fb.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Reviewed-by: David Sterba <dsterba@suse.com> [ added changelog ] Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
There are a few places where we pass in a negative num_bytes, so make it signed for clarity. Also move it up in the file since later patches will need it there. Signed-off-by: Omar Sandoval <osandov@fb.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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David Sterba authored
The XATTR_ITEM is a type of a directory item so we use the common validator helper. Unlike other dir items, it can have data. The way the name len validation is currently implemented does not reflect that. We'd have to adjust by the data_len when comparing the read and item limits. However, this will not work for multi-item xattr dir items. Example from tree dump of generic/337: item 7 key (257 XATTR_ITEM 751495445) itemoff 15667 itemsize 147 location key (0 UNKNOWN.0 0) type XATTR transid 8 data_len 3 name_len 11 name: user.foobar data 123 location key (0 UNKNOWN.0 0) type XATTR transid 8 data_len 6 name_len 13 name: user.WvG1c1Td data qwerty location key (0 UNKNOWN.0 0) type XATTR transid 8 data_len 5 name_len 19 name: user.J3__T_Km3dVsW_ data hello At the point of btrfs_is_name_len_valid call we don't have access to the data_len value of the 2nd and 3rd sub-item. So simple btrfs_dir_data_len(leaf, di) would always return 3, although we'd need to get 6 and 5 respectively to get the claculations right. (read_end + name_len + data_len vs item_end) We'd have to also pass data_len externally, which is not point of the name validation. The last check is supposed to test if there's at least one dir item space after the one we're processing. I don't think this is particularly useful, validation of the next item would catch that too. So the check is removed and we don't weaken the validation. Now tests btrfs/048, btrfs/053, generic/273 and generic/337 pass. Signed-off-by: David Sterba <dsterba@suse.com>
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- 21 Jun, 2017 16 commits
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Su Yue authored
Call verify_dir_item before memcmp_extent_buffer reading name from dir_item. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Su Yue authored
btrfs_del_root_ref calls btrfs_search_slot and reads name from root_ref. Call btrfs_is_name_len_valid before memcmp. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Su Yue authored
In btrfs_get_name, there's btrfs_search_slot and reads name from inode_ref/root_ref. Call btrfs_is_name_len_valid in btrfs_get_name. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Su Yue authored
Since iterate_dir_item checks name_len in its own way, so use btrfs_is_name_len_valid not 'verify_dir_item' to make more strict name_len check. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ switched ENAMETOOLONG to EIO ] Signed-off-by: David Sterba <dsterba@suse.com>
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Su Yue authored
In btrfs_log_inode, btrfs_search_forward gets the buffer and then btrfs_check_ref_name_override will read name from ref/extref for the first time. Call btrfs_is_name_len_valid before reading name. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Su Yue authored
replay_xattr_deletes calls btrfs_search_slot to get buffer and reads name. Call verify_dir_item to check name_len in replay_xattr_deletes to avoid reading out of boundary. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Su Yue authored
replay_one_buffer first reads buffers and dispatches items accroding to the item type. In this patch, add_inode_ref handles inode_ref and inode_extref. Then add_inode_ref calls ref_get_fields and extref_get_fields to read ref/extref name for the first time. So checking name_len before reading those two is fine. add_inode_ref also calls inode_in_dir to match ref/extref in parent_dir. The call graph includes btrfs_match_dir_item_name to read dir_item name in the parent dir. Checking first dir_item is not enough. Change it to verify every dir_item while doing matches. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Su Yue authored
Originally, verify_dir_item verifies name_len of dir_item with fixed values but not item boundary. If corrupted name_len was not bigger than the fixed value, for example 255, the function will think the dir_item is fine. And then reading beyond boundary will cause crash. Example: 1. Corrupt one dir_item name_len to be 255. 2. Run 'ls -lar /mnt/test/ > /dev/null' dmesg: [ 48.451449] BTRFS info (device vdb1): disk space caching is enabled [ 48.451453] BTRFS info (device vdb1): has skinny extents [ 48.489420] general protection fault: 0000 [#1] SMP [ 48.489571] Modules linked in: ext4 jbd2 mbcache btrfs xor raid6_pq [ 48.489716] CPU: 1 PID: 2710 Comm: ls Not tainted 4.10.0-rc1 #5 [ 48.489853] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-20170228_101828-anatol 04/01/2014 [ 48.490008] task: ffff880035df1bc0 task.stack: ffffc90004800000 [ 48.490008] RIP: 0010:read_extent_buffer+0xd2/0x190 [btrfs] [ 48.490008] RSP: 0018:ffffc90004803d98 EFLAGS: 00010202 [ 48.490008] RAX: 000000000000001b RBX: 000000000000001b RCX: 0000000000000000 [ 48.490008] RDX: ffff880079dbf36c RSI: 0005080000000000 RDI: ffff880079dbf368 [ 48.490008] RBP: ffffc90004803dc8 R08: ffff880078e8cc48 R09: ffff880000000000 [ 48.490008] R10: 0000160000000000 R11: 0000000000001000 R12: ffff880079dbf288 [ 48.490008] R13: ffff880078e8ca88 R14: 0000000000000003 R15: ffffc90004803e20 [ 48.490008] FS: 00007fef50c60800(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000 [ 48.490008] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 48.490008] CR2: 000055f335ac2ff8 CR3: 000000007356d000 CR4: 00000000001406e0 [ 48.490008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 48.490008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 48.490008] Call Trace: [ 48.490008] btrfs_real_readdir+0x3b7/0x4a0 [btrfs] [ 48.490008] iterate_dir+0x181/0x1b0 [ 48.490008] SyS_getdents+0xa7/0x150 [ 48.490008] ? fillonedir+0x150/0x150 [ 48.490008] entry_SYSCALL_64_fastpath+0x18/0xad [ 48.490008] RIP: 0033:0x7fef5032546b [ 48.490008] RSP: 002b:00007ffeafcdb830 EFLAGS: 00000206 ORIG_RAX: 000000000000004e [ 48.490008] RAX: ffffffffffffffda RBX: 00007fef5061db38 RCX: 00007fef5032546b [ 48.490008] RDX: 0000000000008000 RSI: 000055f335abaff0 RDI: 0000000000000003 [ 48.490008] RBP: 00007fef5061dae0 R08: 00007fef5061db48 R09: 0000000000000000 [ 48.490008] R10: 000055f335abafc0 R11: 0000000000000206 R12: 00007fef5061db38 [ 48.490008] R13: 0000000000008040 R14: 00007fef5061db38 R15: 000000000000270e [ 48.490008] RIP: read_extent_buffer+0xd2/0x190 [btrfs] RSP: ffffc90004803d98 [ 48.499455] ---[ end trace 321920d8e8339505 ]--- Fix it by adding a parameter @slot and check name_len with item boundary by calling btrfs_is_name_len_valid. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> rev Signed-off-by: David Sterba <dsterba@suse.com>
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Su Yue authored
Introduce function btrfs_is_name_len_valid. The function compares parameter @name_len with item boundary then returns true if name_len is valid. Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ s/btrfs_leaf_data/BTRFS_LEAF_DATA_OFFSET/ ] Signed-off-by: David Sterba <dsterba@suse.com>
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David Sterba authored
We should really just wait in wait_dev_flush and let the caller decide what to do with the error value. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
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David Sterba authored
Similar to what submit_bio_wait does, we should account for IO while waiting for a bio completion. This has marginal visible effects, flush bio is short-lived. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
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David Sterba authored
For devices that support flushing, we allocate a bio, submit, wait for it and then free it. The bio allocation does not fail so ENOMEM is not a problem but we still may unnecessarily stress the allocation subsystem. Instead, we can allocate the bio at the same time we allocate the device and reuse it each time we need to flush the barriers. The bio is reset before each use. Reference counting is simplified to just device allocation (get) and freeing (put). The bio used to be submitted through the integrity checker which will find out that bio has no data attached and call submit_bio. Status of the bio in flight needs to be tracked separately in case the device caches get switched off between write and wait. Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
An incremental send can contain unlink operations with an invalid target path when we rename some directory inode A, then rename some file inode B to the old name of inode A and directory inode A is an ancestor of inode B in the parent snapshot (but not anymore in the send snapshot). Consider the following example scenario where this issue happens. Parent snapshot: . (ino 256) | |--- dir1/ (ino 257) |--- dir2/ (ino 258) | |--- file1 (ino 259) | |--- file3 (ino 261) | |--- dir3/ (ino 262) |--- file22 (ino 260) |--- dir4/ (ino 263) Send snapshot: . (ino 256) | |--- dir1/ (ino 257) |--- dir2/ (ino 258) |--- dir3 (ino 260) |--- file3/ (ino 262) |--- dir4/ (ino 263) |--- file11 (ino 269) |--- file33 (ino 261) When attempting to apply the corresponding incremental send stream, an unlink operation contains an invalid path which makes the receiver fail. The following is verbose output of the btrfs receive command: receiving snapshot snap2 uuid=7d5450da-a573-e043-a451-ec85f4879f0f (...) utimes utimes dir1 utimes dir1/dir2 link dir1/dir3/dir4/file11 -> dir1/dir2/file1 unlink dir1/dir2/file1 utimes dir1/dir2 truncate dir1/dir3/dir4/file11 size=0 utimes dir1/dir3/dir4/file11 rename dir1/dir3 -> o262-7-0 link dir1/dir3 -> o262-7-0/file22 unlink dir1/dir3/file22 ERROR: unlink dir1/dir3/file22 failed. Not a directory The following steps happen during the computation of the incremental send stream the lead to this issue: 1) Before we start processing the new and deleted references for inode 260, we compute the full path of the deleted reference ("dir1/dir3/file22") and cache it in the list of deleted references for our inode. 2) We then start processing the new references for inode 260, for which there is only one new, located at "dir1/dir3". When processing this new reference, we check that inode 262, which was not yet processed, collides with the new reference and because of that we orphanize inode 262 so its new full path becomes "o262-7-0". 3) After the orphanization of inode 262, we create the new reference for inode 260 by issuing a link command with a target path of "dir1/dir3" and a source path of "o262-7-0/file22". 4) We then start processing the deleted references for inode 260, for which there is only one with the base name of "file22", and issue an unlink operation containing the target path computed at step 1, which is wrong because that path no longer exists and should be replaced with "o262-7-0/file22". So fix this issue by recomputing the full path of deleted references if when we processed the new references for an inode we ended up orphanizing any other inode that is an ancestor of our inode in the parent snapshot. A test case for fstests follows soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> [ adjusted after prev patch removed fs_path::dir_path and dir_path_len ] Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
Currently an incremental snapshot can generate link operations which contain an invalid target path. Such case happens when in the send snapshot a file was renamed, a new hard link added for it and some other inode (with a lower number) got renamed to the former name of that file. Example: Parent snapshot . (ino 256) | |--- f1 (ino 257) |--- f2 (ino 258) |--- f3 (ino 259) Send snapshot . (ino 256) | |--- f2 (ino 257) |--- f3 (ino 258) |--- f4 (ino 259) |--- f5 (ino 258) The following steps happen when computing the incremental send stream: 1) When processing inode 257, inode 258 is orphanized (renamed to "o258-7-0"), because its current reference has the same name as the new reference for inode 257; 2) When processing inode 258, we iterate over all its new references, which have the names "f3" and "f5". The first iteration sees name "f5" and renames the inode from its orphan name ("o258-7-0") to "f5", while the second iteration sees the name "f3" and, incorrectly, issues a link operation with a target name matching the orphan name, which no longer exists. The first iteration had reset the current valid path of the inode to "f5", but in the second iteration we lost it because we found another inode, with a higher number of 259, which has a reference named "f3" as well, so we orphanized inode 259 and recomputed the current valid path of inode 258 to its old orphan name because inode 259 could be an ancestor of inode 258 and therefore the current valid path could contain the pre-orphanization name of inode 259. However in this case inode 259 is not an ancestor of inode 258 so the current valid path should not be recomputed. This makes the receiver fail with the following error: ERROR: link f3 -> o258-7-0 failed: No such file or directory So fix this by not recomputing the current valid path for an inode whenever we find a colliding reference from some not yet processed inode (inode number higher then the one currently being processed), unless that other inode is an ancestor of the one we are currently processing. A test case for fstests will follow soon. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
While punching a hole in a range that is not aligned with the sector size (currently the same as the page size) we can end up leaving an extent map in memory with a length that is smaller then the sector size or with a start offset that is not aligned to the sector size. Both cases are not expected and can lead to problems. This issue is easily detected after the patch from commit a7e3b975 ("Btrfs: fix reported number of inode blocks"), introduced in kernel 4.12-rc1, in a scenario like the following for example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -c "pwrite -S 0xaa -b 100K 0 100K" /mnt/foo $ xfs_io -c "fpunch 60K 90K" /mnt/foo $ xfs_io -c "pwrite -S 0xbb -b 100K 50K 100K" /mnt/foo $ xfs_io -c "pwrite -S 0xcc -b 50K 100K 50K" /mnt/foo $ umount /mnt After the unmount operation we can see several warnings emmitted due to underflows related to space reservation counters: [ 2837.443299] ------------[ cut here ]------------ [ 2837.447395] WARNING: CPU: 8 PID: 2474 at fs/btrfs/inode.c:9444 btrfs_destroy_inode+0xe8/0x27e [btrfs] [ 2837.452108] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button se rio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_gene ric raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [ 2837.458389] CPU: 8 PID: 2474 Comm: umount Tainted: G W 4.10.0-rc8-btrfs-next-43+ #1 [ 2837.459754] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 2837.462379] Call Trace: [ 2837.462379] dump_stack+0x68/0x92 [ 2837.462379] __warn+0xc2/0xdd [ 2837.462379] warn_slowpath_null+0x1d/0x1f [ 2837.462379] btrfs_destroy_inode+0xe8/0x27e [btrfs] [ 2837.462379] destroy_inode+0x3d/0x55 [ 2837.462379] evict+0x177/0x17e [ 2837.462379] dispose_list+0x50/0x71 [ 2837.462379] evict_inodes+0x132/0x141 [ 2837.462379] generic_shutdown_super+0x3f/0xeb [ 2837.462379] kill_anon_super+0x12/0x1c [ 2837.462379] btrfs_kill_super+0x16/0x21 [btrfs] [ 2837.462379] deactivate_locked_super+0x30/0x68 [ 2837.462379] deactivate_super+0x36/0x39 [ 2837.462379] cleanup_mnt+0x58/0x76 [ 2837.462379] __cleanup_mnt+0x12/0x14 [ 2837.462379] task_work_run+0x77/0x9b [ 2837.462379] prepare_exit_to_usermode+0x9d/0xc5 [ 2837.462379] syscall_return_slowpath+0x196/0x1b9 [ 2837.462379] entry_SYSCALL_64_fastpath+0xab/0xad [ 2837.462379] RIP: 0033:0x7f3ef3e6b9a7 [ 2837.462379] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 2837.462379] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7 [ 2837.462379] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910 [ 2837.462379] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015 [ 2837.462379] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64 [ 2837.462379] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0 [ 2837.519355] ---[ end trace e79345fe24b30b8d ]--- [ 2837.596256] ------------[ cut here ]------------ [ 2837.597625] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5699 btrfs_free_block_groups+0x246/0x3eb [btrfs] [ 2837.603547] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [ 2837.659372] CPU: 8 PID: 2474 Comm: umount Tainted: G W 4.10.0-rc8-btrfs-next-43+ #1 [ 2837.663359] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 2837.663359] Call Trace: [ 2837.663359] dump_stack+0x68/0x92 [ 2837.663359] __warn+0xc2/0xdd [ 2837.663359] warn_slowpath_null+0x1d/0x1f [ 2837.663359] btrfs_free_block_groups+0x246/0x3eb [btrfs] [ 2837.663359] close_ctree+0x1dd/0x2e1 [btrfs] [ 2837.663359] ? evict_inodes+0x132/0x141 [ 2837.663359] btrfs_put_super+0x15/0x17 [btrfs] [ 2837.663359] generic_shutdown_super+0x6a/0xeb [ 2837.663359] kill_anon_super+0x12/0x1c [ 2837.663359] btrfs_kill_super+0x16/0x21 [btrfs] [ 2837.663359] deactivate_locked_super+0x30/0x68 [ 2837.663359] deactivate_super+0x36/0x39 [ 2837.663359] cleanup_mnt+0x58/0x76 [ 2837.663359] __cleanup_mnt+0x12/0x14 [ 2837.663359] task_work_run+0x77/0x9b [ 2837.663359] prepare_exit_to_usermode+0x9d/0xc5 [ 2837.663359] syscall_return_slowpath+0x196/0x1b9 [ 2837.663359] entry_SYSCALL_64_fastpath+0xab/0xad [ 2837.663359] RIP: 0033:0x7f3ef3e6b9a7 [ 2837.663359] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 2837.663359] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7 [ 2837.663359] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910 [ 2837.663359] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015 [ 2837.663359] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64 [ 2837.663359] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0 [ 2837.739445] ---[ end trace e79345fe24b30b8e ]--- [ 2837.745595] ------------[ cut here ]------------ [ 2837.746412] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5700 btrfs_free_block_groups+0x261/0x3eb [btrfs] [ 2837.747955] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [ 2837.755395] CPU: 8 PID: 2474 Comm: umount Tainted: G W 4.10.0-rc8-btrfs-next-43+ #1 [ 2837.756769] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 2837.758526] Call Trace: [ 2837.758925] dump_stack+0x68/0x92 [ 2837.759383] __warn+0xc2/0xdd [ 2837.759383] warn_slowpath_null+0x1d/0x1f [ 2837.759383] btrfs_free_block_groups+0x261/0x3eb [btrfs] [ 2837.759383] close_ctree+0x1dd/0x2e1 [btrfs] [ 2837.759383] ? evict_inodes+0x132/0x141 [ 2837.759383] btrfs_put_super+0x15/0x17 [btrfs] [ 2837.759383] generic_shutdown_super+0x6a/0xeb [ 2837.759383] kill_anon_super+0x12/0x1c [ 2837.759383] btrfs_kill_super+0x16/0x21 [btrfs] [ 2837.759383] deactivate_locked_super+0x30/0x68 [ 2837.759383] deactivate_super+0x36/0x39 [ 2837.759383] cleanup_mnt+0x58/0x76 [ 2837.759383] __cleanup_mnt+0x12/0x14 [ 2837.759383] task_work_run+0x77/0x9b [ 2837.759383] prepare_exit_to_usermode+0x9d/0xc5 [ 2837.759383] syscall_return_slowpath+0x196/0x1b9 [ 2837.759383] entry_SYSCALL_64_fastpath+0xab/0xad [ 2837.759383] RIP: 0033:0x7f3ef3e6b9a7 [ 2837.759383] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 2837.759383] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7 [ 2837.759383] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910 [ 2837.759383] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015 [ 2837.759383] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64 [ 2837.759383] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0 [ 2837.777063] ---[ end trace e79345fe24b30b8f ]--- [ 2837.778235] ------------[ cut here ]------------ [ 2837.778856] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:9825 btrfs_free_block_groups+0x348/0x3eb [btrfs] [ 2837.791385] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [ 2837.797711] CPU: 8 PID: 2474 Comm: umount Tainted: G W 4.10.0-rc8-btrfs-next-43+ #1 [ 2837.798594] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [ 2837.800118] Call Trace: [ 2837.800515] dump_stack+0x68/0x92 [ 2837.801015] __warn+0xc2/0xdd [ 2837.801471] warn_slowpath_null+0x1d/0x1f [ 2837.801698] btrfs_free_block_groups+0x348/0x3eb [btrfs] [ 2837.801698] close_ctree+0x1dd/0x2e1 [btrfs] [ 2837.801698] ? evict_inodes+0x132/0x141 [ 2837.801698] btrfs_put_super+0x15/0x17 [btrfs] [ 2837.801698] generic_shutdown_super+0x6a/0xeb [ 2837.801698] kill_anon_super+0x12/0x1c [ 2837.801698] btrfs_kill_super+0x16/0x21 [btrfs] [ 2837.801698] deactivate_locked_super+0x30/0x68 [ 2837.801698] deactivate_super+0x36/0x39 [ 2837.801698] cleanup_mnt+0x58/0x76 [ 2837.801698] __cleanup_mnt+0x12/0x14 [ 2837.801698] task_work_run+0x77/0x9b [ 2837.801698] prepare_exit_to_usermode+0x9d/0xc5 [ 2837.801698] syscall_return_slowpath+0x196/0x1b9 [ 2837.801698] entry_SYSCALL_64_fastpath+0xab/0xad [ 2837.801698] RIP: 0033:0x7f3ef3e6b9a7 [ 2837.801698] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 2837.801698] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7 [ 2837.801698] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910 [ 2837.801698] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015 [ 2837.801698] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64 [ 2837.801698] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0 [ 2837.818441] ---[ end trace e79345fe24b30b90 ]--- [ 2837.818991] BTRFS info (device sdc): space_info 1 has 7974912 free, is not full [ 2837.819830] BTRFS info (device sdc): space_info total=8388608, used=417792, pinned=0, reserved=0, may_use=18446744073709547520, readonly=0 What happens in the above example is the following: 1) When punching the hole, at btrfs_punch_hole(), the variable tail_len is set to 2048 (as tail_start is 148Kb + 1 and offset + len is 150Kb). This results in the creation of an extent map with a length of 2Kb starting at file offset 148Kb, through find_first_non_hole() -> btrfs_get_extent(). 2) The second write (first write after the hole punch operation), sets the range [50Kb, 152Kb[ to delalloc. 3) The third write, at btrfs_find_new_delalloc_bytes(), sees the extent map covering the range [148Kb, 150Kb[ and ends up calling set_extent_bit() for the same range, which results in splitting an existing extent state record, covering the range [148Kb, 152Kb[ into two 2Kb extent state records, covering the ranges [148Kb, 150Kb[ and [150Kb, 152Kb[. 4) Finally at lock_and_cleanup_extent_if_need(), immediately after calling btrfs_find_new_delalloc_bytes() we clear the delalloc bit from the range [100Kb, 152Kb[ which results in the btrfs_clear_bit_hook() callback being invoked against the two 2Kb extent state records that cover the ranges [148Kb, 150Kb[ and [150Kb, 152Kb[. When called against the first 2Kb extent state, it calls btrfs_delalloc_release_metadata() with a length argument of 2048 bytes. That function rounds up the length to a sector size aligned length, so it ends up considering a length of 4096 bytes, and then calls calc_csum_metadata_size() which results in decrementing the inode's csum_bytes counter by 4096 bytes, so after it stays a value of 0 bytes. Then the same happens when btrfs_clear_bit_hook() is called against the second extent state that has a length of 2Kb, covering the range [150Kb, 152Kb[, the length is rounded up to 4096 and calc_csum_metadata_size() ends up being called to decrement 4096 bytes from the inode's csum_bytes counter, which at that time has a value of 0, leading to an underflow, which is exactly what triggers the first warning, at btrfs_destroy_inode(). All the other warnings relate to several space accounting counters that underflow as well due to similar reasons. A similar case but where the hole punching operation creates an extent map with a start offset not aligned to the sector size is the following: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "fpunch 695K 820K" $SCRATCH_MNT/bar $ xfs_io -c "pwrite -S 0xaa 1008K 307K" $SCRATCH_MNT/bar $ xfs_io -c "pwrite -S 0xbb -b 630K 1073K 630K" $SCRATCH_MNT/bar $ xfs_io -c "pwrite -S 0xcc -b 459K 1068K 459K" $SCRATCH_MNT/bar $ umount /mnt During the unmount operation we get similar traces for the same reasons as in the first example. So fix the hole punching operation to make sure it never creates extent maps with a length that is not aligned to the sector size nor with a start offset that is not aligned to the sector size, as this breaks all assumptions and it's a land mine. Fixes: d7781546 ("btrfs: Avoid trucating page or punching hole in a already existed hole.") Cc: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Jeff Mahoney authored
On an uncontended system, we can end up hitting soft lockups while doing replace_path. At the core, and frequently called is btrfs_qgroup_trace_leaf_items, so it makes sense to add a cond_resched there. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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- 20 Jun, 2017 2 commits
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Nikolay Borisov authored
We got an internal report about a file system not wanting to mount following 99e3ecfc ("Btrfs: add more validation checks for superblock"). BTRFS error (device sdb1): super_total_bytes 1000203816960 mismatch with fs_devices total_rw_bytes 1000203820544 Subtracting the numbers we get a difference of less than a 4kb. Upon closer inspection it became apparent that mkfs actually rounds down the size of the device to a multiple of sector size. However, the same cannot be said for various functions which modify the total size and are called from btrfs_balance as well as when adding a new device. So this patch ensures that values being saved into on-disk data structures are always rounded down to a multiple of sectorsize. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Nikolay Borisov authored
The device->total_bytes member needs to always be rounded down to sectorsize so that it corresponds to the value of super->total_bytes. However, there are multiple places where the setter is fed a value which is not rounded which can cause a fs to be unmountable due to the check introduced in 99e3ecfc ("Btrfs: add more validation checks for superblock"). This patch implements the getter/setter manually so that in a later patch I can add necessary code to catch offenders. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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