From 383ceb87733bc9483e0058d91c95c24183b4c21f Mon Sep 17 00:00:00 2001 From: Lu Fengqi Date: Wed, 24 Oct 2018 20:24:03 +0800 Subject: btrfs: fix pinned underflow after transaction aborted commit fcd5e74288f7d36991b1f0fb96b8c57079645e38 upstream. When running generic/475, we may get the following warning in dmesg: [ 6902.102154] WARNING: CPU: 3 PID: 18013 at fs/btrfs/extent-tree.c:9776 btrfs_free_block_groups+0x2af/0x3b0 [btrfs] [ 6902.109160] CPU: 3 PID: 18013 Comm: umount Tainted: G W O 4.19.0-rc8+ #8 [ 6902.110971] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 6902.112857] RIP: 0010:btrfs_free_block_groups+0x2af/0x3b0 [btrfs] [ 6902.118921] RSP: 0018:ffffc9000459bdb0 EFLAGS: 00010286 [ 6902.120315] RAX: ffff880175050bb0 RBX: ffff8801124a8000 RCX: 0000000000170007 [ 6902.121969] RDX: 0000000000000002 RSI: 0000000000170007 RDI: ffffffff8125fb74 [ 6902.123716] RBP: ffff880175055d10 R08: 0000000000000000 R09: 0000000000000000 [ 6902.125417] R10: 0000000000000000 R11: 0000000000000000 R12: ffff880175055d88 [ 6902.127129] R13: ffff880175050bb0 R14: 0000000000000000 R15: dead000000000100 [ 6902.129060] FS: 00007f4507223780(0000) GS:ffff88017ba00000(0000) knlGS:0000000000000000 [ 6902.130996] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6902.132558] CR2: 00005623599cac78 CR3: 000000014b700001 CR4: 00000000003606e0 [ 6902.134270] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 6902.135981] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 6902.137836] Call Trace: [ 6902.138939] close_ctree+0x171/0x330 [btrfs] [ 6902.140181] ? kthread_stop+0x146/0x1f0 [ 6902.141277] generic_shutdown_super+0x6c/0x100 [ 6902.142517] kill_anon_super+0x14/0x30 [ 6902.143554] btrfs_kill_super+0x13/0x100 [btrfs] [ 6902.144790] deactivate_locked_super+0x2f/0x70 [ 6902.146014] cleanup_mnt+0x3b/0x70 [ 6902.147020] task_work_run+0x9e/0xd0 [ 6902.148036] do_syscall_64+0x470/0x600 [ 6902.149142] ? trace_hardirqs_off_thunk+0x1a/0x1c [ 6902.150375] entry_SYSCALL_64_after_hwframe+0x49/0xbe [ 6902.151640] RIP: 0033:0x7f45077a6a7b [ 6902.157324] RSP: 002b:00007ffd589f3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 6902.159187] RAX: 0000000000000000 RBX: 000055e8eec732b0 RCX: 00007f45077a6a7b [ 6902.160834] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 000055e8eec73490 [ 6902.162526] RBP: 0000000000000000 R08: 000055e8eec734b0 R09: 00007ffd589f26c0 [ 6902.164141] R10: 0000000000000000 R11: 0000000000000246 R12: 000055e8eec73490 [ 6902.165815] R13: 00007f4507ac61a4 R14: 0000000000000000 R15: 00007ffd589f40d8 [ 6902.167553] irq event stamp: 0 [ 6902.168998] hardirqs last enabled at (0): [<0000000000000000>] (null) [ 6902.170731] hardirqs last disabled at (0): [] copy_process.part.55+0x3b0/0x1f00 [ 6902.172773] softirqs last enabled at (0): [] copy_process.part.55+0x3b0/0x1f00 [ 6902.174671] softirqs last disabled at (0): [<0000000000000000>] (null) [ 6902.176407] ---[ end trace 463138c2986b275c ]--- [ 6902.177636] BTRFS info (device dm-3): space_info 4 has 273465344 free, is not full [ 6902.179453] BTRFS info (device dm-3): space_info total=276824064, used=4685824, pinned=18446744073708158976, reserved=0, may_use=0, readonly=65536 In the above line there's "pinned=18446744073708158976" which is an unsigned u64 value of -1392640, an obvious underflow. When transaction_kthread is running cleanup_transaction(), another fsstress is running btrfs_commit_transaction(). The btrfs_finish_extent_commit() may get the same range as btrfs_destroy_pinned_extent() got, which causes the pinned underflow. Fixes: d4b450cd4b33 ("Btrfs: fix race between transaction commit and empty block group removal") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Josef Bacik Signed-off-by: Lu Fengqi Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/disk-io.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 891b1aab3480..2012eaf80da5 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -4404,13 +4404,23 @@ static int btrfs_destroy_pinned_extent(struct btrfs_fs_info *fs_info, unpin = pinned_extents; again: while (1) { + /* + * The btrfs_finish_extent_commit() may get the same range as + * ours between find_first_extent_bit and clear_extent_dirty. + * Hence, hold the unused_bg_unpin_mutex to avoid double unpin + * the same extent range. + */ + mutex_lock(&fs_info->unused_bg_unpin_mutex); ret = find_first_extent_bit(unpin, 0, &start, &end, EXTENT_DIRTY, NULL); - if (ret) + if (ret) { + mutex_unlock(&fs_info->unused_bg_unpin_mutex); break; + } clear_extent_dirty(unpin, start, end); btrfs_error_unpin_extent_range(fs_info, start, end); + mutex_unlock(&fs_info->unused_bg_unpin_mutex); cond_resched(); } -- cgit v1.2.3 From 1064b11af79de484f9de6474f7af5aedf700ea6d Mon Sep 17 00:00:00 2001 From: Robbie Ko Date: Tue, 30 Oct 2018 18:04:04 +0800 Subject: Btrfs: fix cur_offset in the error case for nocow 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 : [] lr : [] pstate: 40000145 sp : ffffffc02e9af4f0 Process kworker/u8:7 (pid: 31525, stack limit = 0xffffffc02e9ac020) Call trace: [] clear_page_dirty_for_io+0x1bc/0x1e8 [] extent_clear_unlock_delalloc+0x1e4/0x210 [btrfs] [] run_delalloc_nocow+0x3b8/0x948 [btrfs] [] run_delalloc_range+0x250/0x3a8 [btrfs] [] writepage_delalloc.isra.21+0xbc/0x1d8 [btrfs] [] __extent_writepage+0xe8/0x248 [btrfs] [] extent_write_cache_pages.isra.17+0x164/0x378 [btrfs] [] extent_writepages+0x48/0x68 [btrfs] [] btrfs_writepages+0x20/0x30 [btrfs] [] do_writepages+0x30/0x88 [] __writeback_single_inode+0x34/0x198 [] writeback_sb_inodes+0x184/0x3c0 [] __writeback_inodes_wb+0x6c/0xc0 [] wb_writeback+0x1b8/0x1c0 [] wb_workfn+0x150/0x250 [] process_one_work+0x1dc/0x388 [] worker_thread+0x130/0x500 [] kthread+0x10c/0x110 [] ret_from_fork+0x10/0x40 Code: d503201f a9025bb5 a90363b7 f90023b9 (d4210000) CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana Signed-off-by: Robbie Ko Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/inode.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index dc0f9d089b19..3e6c1baddda3 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1537,12 +1537,11 @@ out_check: } btrfs_release_path(path); - if (cur_offset <= end && cow_start == (u64)-1) { + if (cur_offset <= end && cow_start == (u64)-1) cow_start = cur_offset; - cur_offset = end; - } if (cow_start != (u64)-1) { + cur_offset = end; ret = cow_file_range(inode, locked_page, cow_start, end, end, page_started, nr_written, 1, NULL); if (ret) -- cgit v1.2.3 From 0c4fb98c8f6f770d945964edba99de4ff8be75f3 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Mon, 5 Nov 2018 11:14:05 +0000 Subject: Btrfs: fix infinite loop on inode eviction after deduplication of eof block commit 11023d3f5fdf89bba5e1142127701ca6e6014587 upstream. If we attempt to deduplicate the last block of a file A into the middle of a file B, and file A's size is not a multiple of the block size, we end rounding the deduplication length to 0 bytes, to avoid the data corruption issue fixed by commit de02b9f6bb65 ("Btrfs: fix data corruption when deduplicating between different files"). However a length of zero will cause the insertion of an extent state with a start value greater (by 1) then the end value, leading to a corrupt extent state that will trigger a warning and cause chaos such as an infinite loop during inode eviction. Example trace: [96049.833585] ------------[ cut here ]------------ [96049.833714] WARNING: CPU: 0 PID: 24448 at fs/btrfs/extent_io.c:436 insert_state+0x101/0x120 [btrfs] [96049.833767] CPU: 0 PID: 24448 Comm: xfs_io Not tainted 4.19.0-rc7-btrfs-next-39 #1 [96049.833768] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [96049.833780] RIP: 0010:insert_state+0x101/0x120 [btrfs] [96049.833783] RSP: 0018:ffffafd2c3707af0 EFLAGS: 00010282 [96049.833785] RAX: 0000000000000000 RBX: 000000000004dfff RCX: 0000000000000006 [96049.833786] RDX: 0000000000000007 RSI: ffff99045c143230 RDI: ffff99047b2168a0 [96049.833787] RBP: ffff990457851cd0 R08: 0000000000000001 R09: 0000000000000000 [96049.833787] R10: ffffafd2c3707ab8 R11: 0000000000000000 R12: ffff9903b93b12c8 [96049.833788] R13: 000000000004e000 R14: ffffafd2c3707b80 R15: ffffafd2c3707b78 [96049.833790] FS: 00007f5c14e7d700(0000) GS:ffff99047b200000(0000) knlGS:0000000000000000 [96049.833791] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [96049.833792] CR2: 00007f5c146abff8 CR3: 0000000115f4c004 CR4: 00000000003606f0 [96049.833795] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [96049.833796] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [96049.833796] Call Trace: [96049.833809] __set_extent_bit+0x46c/0x6a0 [btrfs] [96049.833823] lock_extent_bits+0x6b/0x210 [btrfs] [96049.833831] ? _raw_spin_unlock+0x24/0x30 [96049.833841] ? test_range_bit+0xdf/0x130 [btrfs] [96049.833853] lock_extent_range+0x8e/0x150 [btrfs] [96049.833864] btrfs_double_extent_lock+0x78/0xb0 [btrfs] [96049.833875] btrfs_extent_same_range+0x14e/0x550 [btrfs] [96049.833885] ? rcu_read_lock_sched_held+0x3f/0x70 [96049.833890] ? __kmalloc_node+0x2b0/0x2f0 [96049.833899] ? btrfs_dedupe_file_range+0x19a/0x280 [btrfs] [96049.833909] btrfs_dedupe_file_range+0x270/0x280 [btrfs] [96049.833916] vfs_dedupe_file_range_one+0xd9/0xe0 [96049.833919] vfs_dedupe_file_range+0x131/0x1b0 [96049.833924] do_vfs_ioctl+0x272/0x6e0 [96049.833927] ? __fget+0x113/0x200 [96049.833931] ksys_ioctl+0x70/0x80 [96049.833933] __x64_sys_ioctl+0x16/0x20 [96049.833937] do_syscall_64+0x60/0x1b0 [96049.833939] entry_SYSCALL_64_after_hwframe+0x49/0xbe [96049.833941] RIP: 0033:0x7f5c1478ddd7 [96049.833943] RSP: 002b:00007ffe15b196a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010 [96049.833945] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5c1478ddd7 [96049.833946] RDX: 00005625ece322d0 RSI: 00000000c0189436 RDI: 0000000000000004 [96049.833947] RBP: 0000000000000000 R08: 00007f5c14a46f48 R09: 0000000000000040 [96049.833948] R10: 0000000000000541 R11: 0000000000000202 R12: 0000000000000000 [96049.833949] R13: 0000000000000000 R14: 0000000000000004 R15: 00005625ece322d0 [96049.833954] irq event stamp: 6196 [96049.833956] hardirqs last enabled at (6195): [] console_unlock+0x503/0x640 [96049.833958] hardirqs last disabled at (6196): [] trace_hardirqs_off_thunk+0x1a/0x1c [96049.833959] softirqs last enabled at (6114): [] __do_softirq+0x370/0x421 [96049.833964] softirqs last disabled at (6095): [] irq_exit+0xcd/0xe0 [96049.833965] ---[ end trace db7b05f01b7fa10c ]--- [96049.935816] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910 [96049.935822] irq event stamp: 6584 [96049.935823] hardirqs last enabled at (6583): [] console_unlock+0x503/0x640 [96049.935825] hardirqs last disabled at (6584): [] trace_hardirqs_off_thunk+0x1a/0x1c [96049.935827] softirqs last enabled at (6328): [] __do_softirq+0x370/0x421 [96049.935828] softirqs last disabled at (6313): [] irq_exit+0xcd/0xe0 [96049.935829] ---[ end trace db7b05f01b7fa123 ]--- [96049.935840] ------------[ cut here ]------------ [96049.936065] WARNING: CPU: 1 PID: 24463 at fs/btrfs/extent_io.c:436 insert_state+0x101/0x120 [btrfs] [96049.936107] CPU: 1 PID: 24463 Comm: umount Tainted: G W 4.19.0-rc7-btrfs-next-39 #1 [96049.936108] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014 [96049.936117] RIP: 0010:insert_state+0x101/0x120 [btrfs] [96049.936119] RSP: 0018:ffffafd2c3637bc0 EFLAGS: 00010282 [96049.936120] RAX: 0000000000000000 RBX: 000000000004dfff RCX: 0000000000000006 [96049.936121] RDX: 0000000000000007 RSI: ffff990445cf88e0 RDI: ffff99047b2968a0 [96049.936122] RBP: ffff990457851cd0 R08: 0000000000000001 R09: 0000000000000000 [96049.936123] R10: ffffafd2c3637b88 R11: 0000000000000000 R12: ffff9904574301e8 [96049.936124] R13: 000000000004e000 R14: ffffafd2c3637c50 R15: ffffafd2c3637c48 [96049.936125] FS: 00007fe4b87e72c0(0000) GS:ffff99047b280000(0000) knlGS:0000000000000000 [96049.936126] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [96049.936128] CR2: 00005562e52618d8 CR3: 00000001151c8005 CR4: 00000000003606e0 [96049.936129] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [96049.936131] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [96049.936131] Call Trace: [96049.936141] __set_extent_bit+0x46c/0x6a0 [btrfs] [96049.936154] lock_extent_bits+0x6b/0x210 [btrfs] [96049.936167] btrfs_evict_inode+0x1e1/0x5a0 [btrfs] [96049.936172] evict+0xbf/0x1c0 [96049.936174] dispose_list+0x51/0x80 [96049.936176] evict_inodes+0x193/0x1c0 [96049.936180] generic_shutdown_super+0x3f/0x110 [96049.936182] kill_anon_super+0xe/0x30 [96049.936189] btrfs_kill_super+0x13/0x100 [btrfs] [96049.936191] deactivate_locked_super+0x3a/0x70 [96049.936193] cleanup_mnt+0x3b/0x80 [96049.936195] task_work_run+0x93/0xc0 [96049.936198] exit_to_usermode_loop+0xfa/0x100 [96049.936201] do_syscall_64+0x17f/0x1b0 [96049.936202] entry_SYSCALL_64_after_hwframe+0x49/0xbe [96049.936204] RIP: 0033:0x7fe4b80cfb37 [96049.936206] RSP: 002b:00007ffff092b688 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [96049.936207] RAX: 0000000000000000 RBX: 00005562e5259060 RCX: 00007fe4b80cfb37 [96049.936208] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 00005562e525faa0 [96049.936209] RBP: 00005562e525faa0 R08: 00005562e525f770 R09: 0000000000000015 [96049.936210] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007fe4b85d1e64 [96049.936211] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910 [96049.936211] R13: 0000000000000000 R14: 00005562e5259240 R15: 00007ffff092b910 [96049.936216] irq event stamp: 6616 [96049.936219] hardirqs last enabled at (6615): [] console_unlock+0x503/0x640 [96049.936219] hardirqs last disabled at (6616): [] trace_hardirqs_off_thunk+0x1a/0x1c [96049.936222] softirqs last enabled at (6328): [] __do_softirq+0x370/0x421 [96049.936222] softirqs last disabled at (6313): [] irq_exit+0xcd/0xe0 [96049.936223] ---[ end trace db7b05f01b7fa124 ]--- The second stack trace, from inode eviction, is repeated forever due to the infinite loop during eviction. This is the same type of problem fixed way back in 2015 by commit 113e8283869b ("Btrfs: fix inode eviction infinite loop after extent_same ioctl") and commit ccccf3d67294 ("Btrfs: fix inode eviction infinite loop after cloning into it"). So fix this by returning immediately if the deduplication range length gets rounded down to 0 bytes, as there is nothing that needs to be done in such case. Example reproducer: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ xfs_io -f -c "pwrite -S 0xe6 0 100" /mnt/foo $ xfs_io -f -c "pwrite -S 0xe6 0 1M" /mnt/bar # Unmount the filesystem and mount it again so that we start without any # extent state records when we ask for the deduplication. $ umount /mnt $ mount /dev/sdb /mnt $ xfs_io -c "dedupe /mnt/foo 0 500K 100" /mnt/bar # This unmount triggers the infinite loop. $ umount /mnt A test case for fstests will follow soon. Fixes: de02b9f6bb65 ("Btrfs: fix data corruption when deduplicating between different files") CC: # 4.19+ Reviewed-by: Nikolay Borisov Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/ioctl.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/btrfs') diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index c972920701a3..54fc470e830c 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3499,6 +3499,8 @@ static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen, const u64 sz = BTRFS_I(src)->root->fs_info->sectorsize; len = round_down(i_size_read(src), sz) - loff; + if (len == 0) + return 0; olen = len; } } -- cgit v1.2.3 From a77da38bfda3ddd99c16befbce48239798fe46de Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Mon, 5 Nov 2018 11:14:17 +0000 Subject: Btrfs: fix data corruption due to cloning of eof block commit ac765f83f1397646c11092a032d4f62c3d478b81 upstream. We currently allow cloning a range from a file which includes the last block of the file even if the file's size is not aligned to the block size. This is fine and useful when the destination file has the same size, but when it does not and the range ends somewhere in the middle of the destination file, it leads to corruption because the bytes between the EOF and the end of the block have undefined data (when there is support for discard/trimming they have a value of 0x00). Example: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ export foo_size=$((256 * 1024 + 100)) $ xfs_io -f -c "pwrite -S 0x3c 0 $foo_size" /mnt/foo $ xfs_io -f -c "pwrite -S 0xb5 0 1M" /mnt/bar $ xfs_io -c "reflink /mnt/foo 0 512K $foo_size" /mnt/bar $ od -A d -t x1 /mnt/bar 0000000 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 * 0524288 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c 3c * 0786528 3c 3c 3c 3c 00 00 00 00 00 00 00 00 00 00 00 00 0786544 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 * 0790528 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 b5 * 1048576 The bytes in the range from 786532 (512Kb + 256Kb + 100 bytes) to 790527 (512Kb + 256Kb + 4Kb - 1) got corrupted, having now a value of 0x00 instead of 0xb5. This is similar to the problem we had for deduplication that got recently fixed by commit de02b9f6bb65 ("Btrfs: fix data corruption when deduplicating between different files"). Fix this by not allowing such operations to be performed and return the errno -EINVAL to user space. This is what XFS is doing as well at the VFS level. This change however now makes us return -EINVAL instead of -EOPNOTSUPP for cases where the source range maps to an inline extent and the destination range's end is smaller then the destination file's size, since the detection of inline extents is done during the actual process of dropping file extent items (at __btrfs_drop_extents()). Returning the -EINVAL error is done early on and solely based on the input parameters (offsets and length) and destination file's size. This makes us consistent with XFS and anyone else supporting cloning since this case is now checked at a higher level in the VFS and is where the -EINVAL will be returned from starting with kernel 4.20 (the VFS changed was introduced in 4.20-rc1 by commit 07d19dc9fbe9 ("vfs: avoid problematic remapping requests into partial EOF block"). So this change is more geared towards stable kernels, as it's unlikely the new VFS checks get removed intentionally. A test case for fstests follows soon, as well as an update to filter existing tests that expect -EOPNOTSUPP to accept -EINVAL as well. CC: # 4.4+ Signed-off-by: Filipe Manana Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/ioctl.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'fs/btrfs') diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 54fc470e830c..ec021bd947ba 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4293,9 +4293,17 @@ static noinline int btrfs_clone_files(struct file *file, struct file *file_src, goto out_unlock; if (len == 0) olen = len = src->i_size - off; - /* if we extend to eof, continue to block boundary */ - if (off + len == src->i_size) + /* + * If we extend to eof, continue to block boundary if and only if the + * destination end offset matches the destination file's size, otherwise + * we would be corrupting data by placing the eof block into the middle + * of a file. + */ + if (off + len == src->i_size) { + if (!IS_ALIGNED(len, bs) && destoff + len < inode->i_size) + goto out_unlock; len = ALIGN(src->i_size, bs) - off; + } if (len == 0) { ret = 0; -- cgit v1.2.3