kernel.git/fs/btrfs/send.c, branch linux-3.14.y

Btrfs: send, don't BUG_ON() when an empty symlink is found

2016-03-03T23:06:50Z

commit a879719b8c90e15c9e7fa7266d5e3c0ca962f9df upstream. When a symlink is successfully created it always has an inline extent containing the source path. However if an error happens when creating the symlink, we can leave in the subvolume's tree a symlink inode without any such inline extent item - this happens if after btrfs_symlink() calls btrfs_end_transaction() and before it calls the inode eviction handler (through the final iput() call), the transaction gets committed and a crash happens before the eviction handler gets called, or if a snapshot of the subvolume is made before the eviction handler gets called. Sadly we can't just avoid this by making btrfs_symlink() call btrfs_end_transaction() after it calls the eviction handler, because the later can commit the current transaction before it removes any items from the subvolume tree (if it encounters ENOSPC errors while reserving space for removing all the items). So make send fail more gracefully, with an -EIO error, and print a message to dmesg/syslog informing that there's an empty symlink inode, so that the user can delete the empty symlink or do something else about it. Reported-by: Stephen R. van den Berg Signed-off-by: Filipe Manana Signed-off-by: Greg Kroah-Hartman

Btrfs: send, fix data corruption due to incorrect hole detection

2014-10-30T16:38:19Z

commit 766b5e5ae78dd04a93a275690a49e23d7dcb1f39 upstream. During an incremental send, when we finish processing an inode (corresponding to a regular file) we would assume the gap between the end of the last processed file extent and the file's size corresponded to a file hole, and therefore incorrectly send a bunch of zero bytes to overwrite that region in the file. This affects only kernel 3.14. Reproducer: mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt xfs_io -f -c "falloc -k 0 268435456" /mnt/foo btrfs subvolume snapshot -r /mnt /mnt/mysnap0 xfs_io -c "pwrite -S 0x01 -b 9216 16190218 9216" /mnt/foo xfs_io -c "pwrite -S 0x02 -b 1121 198720104 1121" /mnt/foo xfs_io -c "pwrite -S 0x05 -b 9216 107887439 9216" /mnt/foo xfs_io -c "pwrite -S 0x06 -b 9216 225520207 9216" /mnt/foo xfs_io -c "pwrite -S 0x07 -b 67584 102138300 67584" /mnt/foo xfs_io -c "pwrite -S 0x08 -b 7000 94897484 7000" /mnt/foo xfs_io -c "pwrite -S 0x09 -b 113664 245083212 113664" /mnt/foo xfs_io -c "pwrite -S 0x10 -b 123 17937788 123" /mnt/foo xfs_io -c "pwrite -S 0x11 -b 39936 229573311 39936" /mnt/foo xfs_io -c "pwrite -S 0x12 -b 67584 174792222 67584" /mnt/foo xfs_io -c "pwrite -S 0x13 -b 9216 249253213 9216" /mnt/foo xfs_io -c "pwrite -S 0x16 -b 67584 150046083 67584" /mnt/foo xfs_io -c "pwrite -S 0x17 -b 39936 118246040 39936" /mnt/foo xfs_io -c "pwrite -S 0x18 -b 67584 215965442 67584" /mnt/foo xfs_io -c "pwrite -S 0x19 -b 33792 97096725 33792" /mnt/foo xfs_io -c "pwrite -S 0x20 -b 125952 166300596 125952" /mnt/foo xfs_io -c "pwrite -S 0x21 -b 123 1078957 123" /mnt/foo xfs_io -c "pwrite -S 0x25 -b 9216 212044492 9216" /mnt/foo xfs_io -c "pwrite -S 0x26 -b 7000 265037146 7000" /mnt/foo xfs_io -c "pwrite -S 0x27 -b 42757 215922685 42757" /mnt/foo xfs_io -c "pwrite -S 0x28 -b 7000 69865411 7000" /mnt/foo xfs_io -c "pwrite -S 0x29 -b 67584 67948958 67584" /mnt/foo xfs_io -c "pwrite -S 0x30 -b 39936 266967019 39936" /mnt/foo xfs_io -c "pwrite -S 0x31 -b 1121 19582453 1121" /mnt/foo xfs_io -c "pwrite -S 0x32 -b 17408 257710255 17408" /mnt/foo xfs_io -c "pwrite -S 0x33 -b 39936 3895518 39936" /mnt/foo xfs_io -c "pwrite -S 0x34 -b 125952 12045847 125952" /mnt/foo xfs_io -c "pwrite -S 0x35 -b 17408 19156379 17408" /mnt/foo xfs_io -c "pwrite -S 0x36 -b 39936 50160066 39936" /mnt/foo xfs_io -c "pwrite -S 0x37 -b 113664 9549793 113664" /mnt/foo xfs_io -c "pwrite -S 0x38 -b 105472 94391506 105472" /mnt/foo xfs_io -c "pwrite -S 0x39 -b 23552 143632863 23552" /mnt/foo xfs_io -c "pwrite -S 0x40 -b 39936 241283845 39936" /mnt/foo xfs_io -c "pwrite -S 0x41 -b 113664 199937606 113664" /mnt/foo xfs_io -c "pwrite -S 0x42 -b 67584 67380093 67584" /mnt/foo xfs_io -c "pwrite -S 0x43 -b 67584 26793129 67584" /mnt/foo xfs_io -c "pwrite -S 0x44 -b 39936 14421913 39936" /mnt/foo xfs_io -c "pwrite -S 0x45 -b 123 253097405 123" /mnt/foo xfs_io -c "pwrite -S 0x46 -b 1121 128233424 1121" /mnt/foo xfs_io -c "pwrite -S 0x47 -b 105472 91577959 105472" /mnt/foo xfs_io -c "pwrite -S 0x48 -b 1121 7245381 1121" /mnt/foo xfs_io -c "pwrite -S 0x49 -b 113664 182414694 113664" /mnt/foo xfs_io -c "pwrite -S 0x50 -b 9216 32750608 9216" /mnt/foo xfs_io -c "pwrite -S 0x51 -b 67584 266546049 67584" /mnt/foo xfs_io -c "pwrite -S 0x52 -b 67584 87969398 67584" /mnt/foo xfs_io -c "pwrite -S 0x53 -b 9216 260848797 9216" /mnt/foo xfs_io -c "pwrite -S 0x54 -b 39936 119461243 39936" /mnt/foo xfs_io -c "pwrite -S 0x55 -b 7000 200178693 7000" /mnt/foo xfs_io -c "pwrite -S 0x56 -b 9216 243316029 9216" /mnt/foo xfs_io -c "pwrite -S 0x57 -b 7000 209658229 7000" /mnt/foo xfs_io -c "pwrite -S 0x58 -b 101376 179745192 101376" /mnt/foo xfs_io -c "pwrite -S 0x59 -b 9216 64012300 9216" /mnt/foo xfs_io -c "pwrite -S 0x60 -b 125952 181705139 125952" /mnt/foo xfs_io -c "pwrite -S 0x61 -b 23552 235737348 23552" /mnt/foo xfs_io -c "pwrite -S 0x62 -b 113664 106021355 113664" /mnt/foo xfs_io -c "pwrite -S 0x63 -b 67584 135753552 67584" /mnt/foo xfs_io -c "pwrite -S 0x64 -b 23552 95730888 23552" /mnt/foo xfs_io -c "pwrite -S 0x65 -b 11 17311415 11" /mnt/foo xfs_io -c "pwrite -S 0x66 -b 33792 120695553 33792" /mnt/foo xfs_io -c "pwrite -S 0x67 -b 9216 17164631 9216" /mnt/foo xfs_io -c "pwrite -S 0x68 -b 9216 136065853 9216" /mnt/foo xfs_io -c "pwrite -S 0x69 -b 67584 37752198 67584" /mnt/foo xfs_io -c "pwrite -S 0x70 -b 101376 189717473 101376" /mnt/foo xfs_io -c "pwrite -S 0x71 -b 7000 227463698 7000" /mnt/foo xfs_io -c "pwrite -S 0x72 -b 9216 12655137 9216" /mnt/foo xfs_io -c "pwrite -S 0x73 -b 7000 7488866 7000" /mnt/foo xfs_io -c "pwrite -S 0x74 -b 113664 87813649 113664" /mnt/foo xfs_io -c "pwrite -S 0x75 -b 33792 25802183 33792" /mnt/foo xfs_io -c "pwrite -S 0x76 -b 39936 93524024 39936" /mnt/foo xfs_io -c "pwrite -S 0x77 -b 33792 113336388 33792" /mnt/foo xfs_io -c "pwrite -S 0x78 -b 105472 184955320 105472" /mnt/foo xfs_io -c "pwrite -S 0x79 -b 101376 225691598 101376" /mnt/foo xfs_io -c "pwrite -S 0x80 -b 23552 77023155 23552" /mnt/foo xfs_io -c "pwrite -S 0x81 -b 11 201888192 11" /mnt/foo xfs_io -c "pwrite -S 0x82 -b 11 115332492 11" /mnt/foo xfs_io -c "pwrite -S 0x83 -b 67584 230278015 67584" /mnt/foo xfs_io -c "pwrite -S 0x84 -b 11 120589073 11" /mnt/foo xfs_io -c "pwrite -S 0x85 -b 125952 202207819 125952" /mnt/foo xfs_io -c "pwrite -S 0x86 -b 113664 86672080 113664" /mnt/foo xfs_io -c "pwrite -S 0x87 -b 17408 208459603 17408" /mnt/foo xfs_io -c "pwrite -S 0x88 -b 7000 73372211 7000" /mnt/foo xfs_io -c "pwrite -S 0x89 -b 7000 42252122 7000" /mnt/foo xfs_io -c "pwrite -S 0x90 -b 23552 46784881 23552" /mnt/foo xfs_io -c "pwrite -S 0x91 -b 101376 63172351 101376" /mnt/foo xfs_io -c "pwrite -S 0x92 -b 23552 59341931 23552" /mnt/foo xfs_io -c "pwrite -S 0x93 -b 39936 239599283 39936" /mnt/foo xfs_io -c "pwrite -S 0x94 -b 67584 175643105 67584" /mnt/foo xfs_io -c "pwrite -S 0x97 -b 23552 105534880 23552" /mnt/foo xfs_io -c "pwrite -S 0x98 -b 113664 8236844 113664" /mnt/foo xfs_io -c "pwrite -S 0x99 -b 125952 144489686 125952" /mnt/foo xfs_io -c "pwrite -S 0xa0 -b 7000 73273112 7000" /mnt/foo xfs_io -c "pwrite -S 0xa1 -b 125952 194580243 125952" /mnt/foo xfs_io -c "pwrite -S 0xa2 -b 123 56296779 123" /mnt/foo xfs_io -c "pwrite -S 0xa3 -b 11 233066845 11" /mnt/foo xfs_io -c "pwrite -S 0xa4 -b 39936 197727090 39936" /mnt/foo xfs_io -c "pwrite -S 0xa5 -b 101376 53579812 101376" /mnt/foo xfs_io -c "pwrite -S 0xa6 -b 9216 85669738 9216" /mnt/foo xfs_io -c "pwrite -S 0xa7 -b 125952 21266322 125952" /mnt/foo xfs_io -c "pwrite -S 0xa8 -b 23552 125726568 23552" /mnt/foo xfs_io -c "pwrite -S 0xa9 -b 9216 18423680 9216" /mnt/foo xfs_io -c "pwrite -S 0xb0 -b 1121 165901483 1121" /mnt/foo btrfs subvolume snapshot -r /mnt /mnt/mysnap1 xfs_io -c "pwrite -S 0xff -b 10 16190218 10" /mnt/foo btrfs subvolume snapshot -r /mnt /mnt/mysnap2 md5sum /mnt/foo # returns 79e53f1466bfc09fd82b450689e6119e md5sum /mnt/mysnap2/foo # returns 79e53f1466bfc09fd82b450689e6119e too btrfs send /mnt/mysnap1 -f /tmp/1.snap btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/2.snap mkfs.btrfs -f /dev/sdc mount /dev/sdc /mnt btrfs receive /mnt -f /tmp/1.snap btrfs receive /mnt -f /tmp/2.snap md5sum /mnt/mysnap2/foo # returns 2bb414c5155767cedccd7063e51beabd !! A testcase for xfstests follows soon too. Signed-off-by: Filipe David Borba Manana Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman

Btrfs: send, don't error in the presence of subvols/snapshots

2014-07-01T03:12:01Z

commit 1af56070e3ef9477dbc7eba3b9ad7446979c7974 upstream. If we are doing an incremental send and the base snapshot has a directory with name X that doesn't exist anymore in the second snapshot and a new subvolume/snapshot exists in the second snapshot that has the same name as the directory (name X), the incremental send would fail with -ENOENT error. This is because it attempts to lookup for an inode with a number matching the objectid of a root, which doesn't exist. Steps to reproduce: mkfs.btrfs -f /dev/sdd mount /dev/sdd /mnt mkdir /mnt/testdir btrfs subvolume snapshot -r /mnt /mnt/mysnap1 rmdir /mnt/testdir btrfs subvolume create /mnt/testdir btrfs subvolume snapshot -r /mnt /mnt/mysnap2 btrfs send -p /mnt/mysnap1 /mnt/mysnap2 -f /tmp/send.data A test case for xfstests follows. Reported-by: Robert White Signed-off-by: Filipe David Borba Manana Signed-off-by: Chris Mason Signed-off-by: Greg Kroah-Hartman

Btrfs: use right clone root offset for compressed extents

2014-02-15T16:04:27Z

For non compressed extents, iterate_extent_inodes() gives us offsets that take into account the data offset from the file extent items, while for compressed extents it doesn't. Therefore we have to adjust them before placing them in a send clone instruction. Not doing this adjustment leads to the receiving end requesting for a wrong a file range to the clone ioctl, which results in different file content from the one in the original send root. Issue reproducible with the following excerpt from the test I made for xfstests: _scratch_mkfs _scratch_mount "-o compress-force=lzo" $XFS_IO_PROG -f -c "truncate 118811" $SCRATCH_MNT/foo $XFS_IO_PROG -c "pwrite -S 0x0d -b 39987 92267 39987" $SCRATCH_MNT/foo $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap1 $XFS_IO_PROG -c "pwrite -S 0x3e -b 80000 200000 80000" $SCRATCH_MNT/foo $BTRFS_UTIL_PROG filesystem sync $SCRATCH_MNT $XFS_IO_PROG -c "pwrite -S 0xdc -b 10000 250000 10000" $SCRATCH_MNT/foo $XFS_IO_PROG -c "pwrite -S 0xff -b 10000 300000 10000" $SCRATCH_MNT/foo # will be used for incremental send to be able to issue clone operations $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/clones_snap $BTRFS_UTIL_PROG subvolume snapshot -r $SCRATCH_MNT $SCRATCH_MNT/mysnap2 $FSSUM_PROG -A -f -w $tmp/1.fssum $SCRATCH_MNT/mysnap1 $FSSUM_PROG -A -f -w $tmp/2.fssum -x $SCRATCH_MNT/mysnap2/mysnap1 \ -x $SCRATCH_MNT/mysnap2/clones_snap $SCRATCH_MNT/mysnap2 $FSSUM_PROG -A -f -w $tmp/clones.fssum $SCRATCH_MNT/clones_snap \ -x $SCRATCH_MNT/clones_snap/mysnap1 -x $SCRATCH_MNT/clones_snap/mysnap2 $BTRFS_UTIL_PROG send $SCRATCH_MNT/mysnap1 -f $tmp/1.snap $BTRFS_UTIL_PROG send $SCRATCH_MNT/clones_snap -f $tmp/clones.snap $BTRFS_UTIL_PROG send -p $SCRATCH_MNT/mysnap1 \ -c $SCRATCH_MNT/clones_snap $SCRATCH_MNT/mysnap2 -f $tmp/2.snap _scratch_unmount _scratch_mkfs _scratch_mount $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/1.snap $FSSUM_PROG -r $tmp/1.fssum $SCRATCH_MNT/mysnap1 2>> $seqres.full $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/clones.snap $FSSUM_PROG -r $tmp/clones.fssum $SCRATCH_MNT/clones_snap 2>> $seqres.full $BTRFS_UTIL_PROG receive $SCRATCH_MNT -f $tmp/2.snap $FSSUM_PROG -r $tmp/2.fssum $SCRATCH_MNT/mysnap2 2>> $seqres.full Signed-off-by: Filipe David Borba Manana Signed-off-by: Chris Mason

Btrfs: fix assert screwup for the pending move stuff

2014-02-09T01:57:15Z

Wang noticed that he was failing btrfs/030 even though me and Filipe couldn't reproduce. Turns out this is because Wang didn't have CONFIG_BTRFS_ASSERT set, which meant that a key part of Filipe's original patch was not being built in. This appears to be a mess up with merging Filipe's patch as it does not exist in his original patch. Fix this by changing how we make sure del_waiting_dir_move asserts that it did not error and take the function out of the ifdef check. This makes btrfs/030 pass with the assert on or off. Thanks, Signed-off-by: Josef Bacik Reviewed-by: Filipe Manana Signed-off-by: Chris Mason

Btrfs: use btrfs_crc32c everywhere instead of libcrc32c

2014-02-03T17:01:27Z

After the commit titled "Btrfs: fix btrfs boot when compiled as built-in", LIBCRC32C requirement was removed from btrfs' Kconfig. This made it not possible to build a kernel with btrfs enabled (either as module or built-in) if libcrc32c is not enabled as well. So just replace all uses of libcrc32c with the equivalent function in btrfs hash.h - btrfs_crc32c. Signed-off-by: Filipe David Borba Manana Signed-off-by: Chris Mason

Btrfs: don't use ram_bytes for uncompressed inline items

2014-01-29T15:06:29Z

If we truncate an uncompressed inline item, ram_bytes isn't updated to reflect the new size. The fixe uses the size directly from the item header when reading uncompressed inlines, and also fixes truncate to update the size as it goes. Reported-by: Jens Axboe Signed-off-by: Chris Mason CC: stable@vger.kernel.org

Btrfs: fix send file hole detection leading to data corruption

2014-01-29T15:06:25Z

There was a case where file hole detection was incorrect and it would cause an incremental send to override a section of a file with zeroes. This happened in the case where between the last leaf we processed which contained a file extent item for our current inode and the leaf we're currently are at (and has a file extent item for our current inode) there are only leafs containing exclusively file extent items for our current inode, and none of them was updated since the previous send operation. The file hole detection code would incorrectly consider the file range covered by these leafs as a hole. A test case for xfstests follows soon. Signed-off-by: Filipe David Borba Manana Signed-off-by: Josef Bacik Signed-off-by: Chris Mason

Btrfs: make send's file extent item search more efficient

2014-01-29T15:06:24Z

Instead of looking for a file extent item, process it, release the path and do a btree search for the next file extent item, just process all file extent items in a leaf without intermediate btree searches. This way we save cpu and we're not blocking other tasks or affecting concurrency on the btree, because send's paths use the commit root and skip btree node/leaf locking. Signed-off-by: Filipe David Borba Manana Signed-off-by: Josef Bacik Signed-off-by: Chris Mason

Btrfs: fix infinite path build loops in incremental send

2014-01-29T15:06:22Z

The send operation processes inodes by their ascending number, and assumes that any rename/move operation can be successfully performed (sent to the caller) once all previous inodes (those with a smaller inode number than the one we're currently processing) were processed. This is not true when an incremental send had to process an hierarchical change between 2 snapshots where the parent-children relationship between directory inodes was reversed - that is, parents became children and children became parents. This situation made the path building code go into an infinite loop, which kept allocating more and more memory that eventually lead to a krealloc warning being displayed in dmesg: WARNING: CPU: 1 PID: 5705 at mm/page_alloc.c:2477 __alloc_pages_nodemask+0x365/0xad0() Modules linked in: btrfs raid6_pq xor pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) snd_hda_codec_hdmi snd_hda_codec_realtek joydev radeon snd_hda_intel snd_hda_codec snd_hwdep snd_seq_midi snd_pcm psmouse i915 snd_rawmidi serio_raw snd_seq_midi_event lpc_ich snd_seq snd_timer ttm snd_seq_device rfcomm drm_kms_helper parport_pc bnep bluetooth drm ppdev snd soundcore i2c_algo_bit snd_page_alloc binfmt_misc video lp parport r8169 mii hid_generic usbhid hid CPU: 1 PID: 5705 Comm: btrfs Tainted: G O 3.13.0-rc7-fdm-btrfs-next-18+ #3 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./Z77 Pro4, BIOS P1.50 09/04/2012 [ 5381.660441] 00000000000009ad ffff8806f6f2f4e8 ffffffff81777434 0000000000000007 [ 5381.660447] 0000000000000000 ffff8806f6f2f528 ffffffff8104a9ec ffff8807038f36f0 [ 5381.660452] 0000000000000000 0000000000000206 ffff8807038f2490 ffff8807038f36f0 [ 5381.660457] Call Trace: [ 5381.660464] [] dump_stack+0x4e/0x68 [ 5381.660471] [] warn_slowpath_common+0x8c/0xc0 [ 5381.660476] [] warn_slowpath_null+0x1a/0x20 [ 5381.660480] [] __alloc_pages_nodemask+0x365/0xad0 [ 5381.660487] [] ? local_clock+0x4f/0x60 [ 5381.660491] [] ? free_one_page+0x98/0x440 [ 5381.660495] [] ? local_clock+0x4f/0x60 [ 5381.660502] [] ? __get_free_pages+0x14/0x50 [ 5381.660508] [] ? trace_hardirqs_off_caller+0x28/0xd0 [ 5381.660515] [] alloc_pages_current+0x10f/0x1f0 [ 5381.660520] [] ? __get_free_pages+0x14/0x50 [ 5381.660524] [] __get_free_pages+0x14/0x50 [ 5381.660530] [] kmalloc_order_trace+0x3e/0x100 [ 5381.660536] [] __kmalloc_track_caller+0x220/0x230 [ 5381.660560] [] ? fs_path_ensure_buf.part.12+0x6b/0x200 [btrfs] [ 5381.660564] [] ? retint_restore_args+0xe/0xe [ 5381.660569] [] krealloc+0x6f/0xb0 [ 5381.660586] [] fs_path_ensure_buf.part.12+0x6b/0x200 [btrfs] [ 5381.660601] [] fs_path_prepare_for_add+0x98/0xb0 [btrfs] [ 5381.660615] [] fs_path_add_path+0x2c/0x60 [btrfs] [ 5381.660628] [] get_cur_path+0x7c/0x1c0 [btrfs] Even without this loop, the incremental send couldn't succeed, because it would attempt to send a rename/move operation for the lower inode before the highest inode number was renamed/move. This issue is easy to trigger with the following steps: $ mkfs.btrfs -f /dev/sdb3 $ mount /dev/sdb3 /mnt/btrfs $ mkdir -p /mnt/btrfs/a/b/c/d $ mkdir /mnt/btrfs/a/b/c2 $ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap1 $ mv /mnt/btrfs/a/b/c/d /mnt/btrfs/a/b/c2/d2 $ mv /mnt/btrfs/a/b/c /mnt/btrfs/a/b/c2/d2/cc $ btrfs subvol snapshot -r /mnt/btrfs /mnt/btrfs/snap2 $ btrfs send -p /mnt/btrfs/snap1 /mnt/btrfs/snap2 > /tmp/incremental.send The structure of the filesystem when the first snapshot is taken is: . (ino 256) |-- a (ino 257) |-- b (ino 258) |-- c (ino 259) | |-- d (ino 260) | |-- c2 (ino 261) And its structure when the second snapshot is taken is: . (ino 256) |-- a (ino 257) |-- b (ino 258) |-- c2 (ino 261) |-- d2 (ino 260) |-- cc (ino 259) Before the move/rename operation is performed for the inode 259, the move/rename for inode 260 must be performed, since 259 is now a child of 260. A test case for xfstests, with a more complex scenario, will follow soon. Signed-off-by: Filipe David Borba Manana Signed-off-by: Josef Bacik Signed-off-by: Chris Mason