linux-toradex.git/fs/btrfs/inode-item.c, branch v5.1

btrfs: replace GPL boilerplate by SPDX -- sources

2018-04-12T14:29:51+00:00

Remove GPL boilerplate text (long, short, one-line) and keep the rest,
ie. personal, company or original source copyright statements. Add the
SPDX header.

Signed-off-by: David Sterba

btrfs: Remove custom crc32c init code

2018-03-26T13:09:39+00:00

The custom crc32 init code was introduced in
14a958e678cd ("Btrfs: fix btrfs boot when compiled as built-in") to
enable using btrfs as a built-in. However, later as pointed out by
60efa5eb2e88 ("Btrfs: use late_initcall instead of module_init") this
wasn't enough and finally btrfs was switched to late_initcall which
comes after the generic crc32c implementation is initiliased. The
latter commit superseeded the former. Now that we don't have to
maintain our own code let's just remove it and switch to using the
generic implementation.

Despite touching a lot of files the patch is really simple. Here is the gist of
the changes:

1. Select LIBCRC32C rather than the low-level modules.
2. s/btrfs_crc32c/crc32c/g
3. replace hash.h with linux/crc32c.h
4. Move the btrfs namehash funcs to ctree.h and change the tree accordingly.

I've tested this with btrfs being both a module and a built-in and xfstest
doesn't complain.

Does seem to fix the longstanding problem of not automatically selectiong
the crc32c module when btrfs is used. Possibly there is a workaround in
dracut.

The modinfo confirms that now all the module dependencies are there:

before:
depends:        zstd_compress,zstd_decompress,raid6_pq,xor,zlib_deflate

after:
depends:        libcrc32c,zstd_compress,zstd_decompress,raid6_pq,xor,zlib_deflate

Signed-off-by: Nikolay Borisov 
Reviewed-by: David Sterba 
[ add more info to changelog from mails ]
Signed-off-by: David Sterba

Btrfs: fix log replay failure after unlink and link combination

2018-03-01T15:18:40+00:00

If we have a file with 2 (or more) hard links in the same directory,
remove one of the hard links, create a new file (or link an existing file)
in the same directory with the name of the removed hard link, and then
finally fsync the new file, we end up with a log that fails to replay,
causing a mount failure.

Example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ mkdir /mnt/testdir
  $ touch /mnt/testdir/foo
  $ ln /mnt/testdir/foo /mnt/testdir/bar

  $ sync

  $ unlink /mnt/testdir/bar
  $ touch /mnt/testdir/bar
  $ xfs_io -c "fsync" /mnt/testdir/bar

  

  $ mount /dev/sdb /mnt
  mount: mount(2) failed: /mnt: No such file or directory

When replaying the log, for that example, we also see the following in
dmesg/syslog:

  [71813.671307] BTRFS info (device dm-0): failed to delete reference to bar, inode 258 parent 257
  [71813.674204] ------------[ cut here ]------------
  [71813.675694] BTRFS: Transaction aborted (error -2)
  [71813.677236] WARNING: CPU: 1 PID: 13231 at fs/btrfs/inode.c:4128 __btrfs_unlink_inode+0x17b/0x355 [btrfs]
  [71813.679669] Modules linked in: btrfs xfs f2fs dm_flakey dm_mod dax ghash_clmulni_intel ppdev pcbc aesni_intel aes_x86_64 crypto_simd cryptd glue_helper evdev psmouse i2c_piix4 parport_pc i2c_core pcspkr sg serio_raw parport button sunrpc loop autofs4 ext4 crc16 mbcache jbd2 zstd_decompress zstd_compress xxhash 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 ata_generic sd_mod virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel floppy virtio e1000 scsi_mod [last unloaded: btrfs]
  [71813.679669] CPU: 1 PID: 13231 Comm: mount Tainted: G        W        4.15.0-rc9-btrfs-next-56+ #1
  [71813.679669] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
  [71813.679669] RIP: 0010:__btrfs_unlink_inode+0x17b/0x355 [btrfs]
  [71813.679669] RSP: 0018:ffffc90001cef738 EFLAGS: 00010286
  [71813.679669] RAX: 0000000000000025 RBX: ffff880217ce4708 RCX: 0000000000000001
  [71813.679669] RDX: 0000000000000000 RSI: ffffffff81c14bae RDI: 00000000ffffffff
  [71813.679669] RBP: ffffc90001cef7c0 R08: 0000000000000001 R09: 0000000000000001
  [71813.679669] R10: ffffc90001cef5e0 R11: ffffffff8343f007 R12: ffff880217d474c8
  [71813.679669] R13: 00000000fffffffe R14: ffff88021ccf1548 R15: 0000000000000101
  [71813.679669] FS:  00007f7cee84c480(0000) GS:ffff88023fc80000(0000) knlGS:0000000000000000
  [71813.679669] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [71813.679669] CR2: 00007f7cedc1abf9 CR3: 00000002354b4003 CR4: 00000000001606e0
  [71813.679669] Call Trace:
  [71813.679669]  btrfs_unlink_inode+0x17/0x41 [btrfs]
  [71813.679669]  drop_one_dir_item+0xfa/0x131 [btrfs]
  [71813.679669]  add_inode_ref+0x71e/0x851 [btrfs]
  [71813.679669]  ? __lock_is_held+0x39/0x71
  [71813.679669]  ? replay_one_buffer+0x53/0x53a [btrfs]
  [71813.679669]  replay_one_buffer+0x4a4/0x53a [btrfs]
  [71813.679669]  ? rcu_read_unlock+0x3a/0x57
  [71813.679669]  ? __lock_is_held+0x39/0x71
  [71813.679669]  walk_up_log_tree+0x101/0x1d2 [btrfs]
  [71813.679669]  walk_log_tree+0xad/0x188 [btrfs]
  [71813.679669]  btrfs_recover_log_trees+0x1fa/0x31e [btrfs]
  [71813.679669]  ? replay_one_extent+0x544/0x544 [btrfs]
  [71813.679669]  open_ctree+0x1cf6/0x2209 [btrfs]
  [71813.679669]  btrfs_mount_root+0x368/0x482 [btrfs]
  [71813.679669]  ? trace_hardirqs_on_caller+0x14c/0x1a6
  [71813.679669]  ? __lockdep_init_map+0x176/0x1c2
  [71813.679669]  ? mount_fs+0x64/0x10b
  [71813.679669]  mount_fs+0x64/0x10b
  [71813.679669]  vfs_kern_mount+0x68/0xce
  [71813.679669]  btrfs_mount+0x13e/0x772 [btrfs]
  [71813.679669]  ? trace_hardirqs_on_caller+0x14c/0x1a6
  [71813.679669]  ? __lockdep_init_map+0x176/0x1c2
  [71813.679669]  ? mount_fs+0x64/0x10b
  [71813.679669]  mount_fs+0x64/0x10b
  [71813.679669]  vfs_kern_mount+0x68/0xce
  [71813.679669]  do_mount+0x6e5/0x973
  [71813.679669]  ? memdup_user+0x3e/0x5c
  [71813.679669]  SyS_mount+0x72/0x98
  [71813.679669]  entry_SYSCALL_64_fastpath+0x1e/0x8b
  [71813.679669] RIP: 0033:0x7f7cedf150ba
  [71813.679669] RSP: 002b:00007ffca71da688 EFLAGS: 00000206
  [71813.679669] Code: 7f a0 e8 51 0c fd ff 48 8b 43 50 f0 0f ba a8 30 2c 00 00 02 72 17 41 83 fd fb 74 11 44 89 ee 48 c7 c7 7d 11 7f a0 e8 38 f5 8d e0 <0f> ff 44 89 e9 ba 20 10 00 00 eb 4d 48 8b 4d b0 48 8b 75 88 4c
  [71813.679669] ---[ end trace 83bd473fc5b4663b ]---
  [71813.854764] BTRFS: error (device dm-0) in __btrfs_unlink_inode:4128: errno=-2 No such entry
  [71813.886994] BTRFS: error (device dm-0) in btrfs_replay_log:2307: errno=-2 No such entry (Failed to recover log tree)
  [71813.903357] BTRFS error (device dm-0): cleaner transaction attach returned -30
  [71814.128078] BTRFS error (device dm-0): open_ctree failed

This happens because the log has inode reference items for both inode 258
(the first file we created) and inode 259 (the second file created), and
when processing the reference item for inode 258, we replace the
corresponding item in the subvolume tree (which has two names, "foo" and
"bar") witht he one in the log (which only has one name, "foo") without
removing the corresponding dir index keys from the parent directory.
Later, when processing the inode reference item for inode 259, which has
a name of "bar" associated to it, we notice that dir index entries exist
for that name and for a different inode, so we attempt to unlink that
name, which fails because the inode reference item for inode 258 no longer
has the name "bar" associated to it, making a call to btrfs_unlink_inode()
fail with a -ENOENT error.

Fix this by unlinking all the names in an inode reference item from a
subvolume tree that are not present in the inode reference item found in
the log tree, before overwriting it with the item from the log tree.

Signed-off-by: Filipe Manana 
Signed-off-by: David Sterba

btrfs: take an fs_info directly when the root is not used otherwise

2016-12-06T15:06:59+00:00

There are loads of functions in btrfs that accept a root parameter
but only use it to obtain an fs_info pointer.  Let's convert those to
just accept an fs_info pointer directly.

Signed-off-by: Jeff Mahoney 
Signed-off-by: David Sterba

btrfs: root->fs_info cleanup, add fs_info convenience variables

2016-12-06T15:06:59+00:00

In routines where someptr->fs_info is referenced multiple times, we
introduce a convenience variable.  This makes the code considerably
more readable.

Signed-off-by: Jeff Mahoney 
Signed-off-by: David Sterba

btrfs: rename btrfs_std_error to btrfs_handle_fs_error

2016-04-28T08:36:54+00:00

btrfs_std_error() handles errors, puts FS into readonly mode
(as of now). So its good idea to rename it to btrfs_handle_fs_error().

Signed-off-by: Anand Jain 
Reviewed-by: David Sterba 
[ edit changelog ]
Signed-off-by: David Sterba

Btrfs: consolidate btrfs_error() to btrfs_std_error()

2015-09-29T14:30:00+00:00

btrfs_error() and btrfs_std_error() does the same thing
and calls _btrfs_std_error(), so consolidate them together.
And the main motivation is that btrfs_error() is closely
named with btrfs_err(), one handles error action the other
is to log the error, so don't closely name them.

Signed-off-by: Anand Jain 
Suggested-by: David Sterba 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

Btrfs: fix fsync log replay for inodes with a mix of regular refs and extrefs

2015-01-22T02:02:05+00:00

If we have an inode with a large number of hard links, some of which may
be extrefs, turn a regular ref into an extref, fsync the inode and then
replay the fsync log (after a crash/reboot), we can endup with an fsync
log that makes the replay code always fail with -EOVERFLOW when processing
the inode's references.

This is easy to reproduce with the test case I made for xfstests. Its steps
are the following:

   _scratch_mkfs "-O extref" >> $seqres.full 2>&1
   _init_flakey
   _mount_flakey

   # Create a test file with 3001 hard links. This number is large enough to
   # make btrfs start using extrefs at some point even if the fs has the maximum
   # possible leaf/node size (64Kb).
   echo "hello world" > $SCRATCH_MNT/foo
   for i in `seq 1 3000`; do
       ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_`printf "%04d" $i`
   done

   # Make sure all metadata and data are durably persisted.
   sync

   # Now remove one link, add a new one with a new name, add another new one with
   # the same name as the one we just removed and fsync the inode.
   rm -f $SCRATCH_MNT/foo_link_0001
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3001
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_0001
   rm -f $SCRATCH_MNT/foo_link_0002
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3002
   ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link_3003
   $XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo

   # Simulate a crash/power loss. This makes sure the next mount
   # will see an fsync log and will replay that log.

   _load_flakey_table $FLAKEY_DROP_WRITES
   _unmount_flakey

   _load_flakey_table $FLAKEY_ALLOW_WRITES
   _mount_flakey

   # Check that the number of hard links is correct, we are able to remove all
   # the hard links and read the file's data. This is just to verify we don't
   # get stale file handle errors (due to dangling directory index entries that
   # point to inodes that no longer exist).
   echo "Link count: $(stat --format=%h $SCRATCH_MNT/foo)"
   [ -f $SCRATCH_MNT/foo ] || echo "Link foo is missing"
   for ((i = 1; i <= 3003; i++)); do
       name=foo_link_`printf "%04d" $i`
       if [ $i -eq 2 ]; then
           [ -f $SCRATCH_MNT/$name ] && echo "Link $name found"
       else
           [ -f $SCRATCH_MNT/$name ] || echo "Link $name is missing"
       fi
   done
   rm -f $SCRATCH_MNT/foo_link_*
   cat $SCRATCH_MNT/foo
   rm -f $SCRATCH_MNT/foo

   status=0
   exit

The fix is simply to correct the overflow condition when overwriting a
reference item because it was wrong, trying to increase the item in the
fs/subvol tree by an impossible amount. Also ensure that we don't insert
one normal ref and one ext ref for the same dentry - this happened because
processing a dir index entry from the parent in the log happened when
the normal ref item was full, which made the logic insert an extref and
later when the normal ref had enough room, it would be inserted again
when processing the ref item from the child inode in the log.

This issue has been present since the introduction of the extrefs feature
(2012).

A test case for xfstests follows soon. This test only passes if the previous
patch titled "Btrfs: fix fsync when extend references are added to an inode"
is applied too.

Signed-off-by: Filipe Manana 
Signed-off-by: Chris Mason

btrfs: kill the key type accessor helpers

2014-09-17T20:37:12+00:00

btrfs_set_key_type and btrfs_key_type are used inconsistently along with
open coded variants. Other members of btrfs_key are accessed directly
without any helpers anyway.

Signed-off-by: David Sterba 
Signed-off-by: Chris Mason

btrfs: cleanup: removed unused 'btrfs_get_inode_ref_index'

2014-01-28T21:19:39+00:00

Found by uselex.rb:
> btrfs_get_inode_ref_index: [R]: exported from:
fs/btrfs/inode-item.o fs/btrfs/btrfs.o fs/btrfs/built-in.o

Signed-off-by: Sergei Trofimovich 
Reviewed-by: David Stebra 
Signed-off-by: Wang Shilong 
Signed-off-by: Josef Bacik 
Signed-off-by: Chris Mason