linux-toradex.git/fs/ext4/inode.c, branch v3.4.16

ext4: fix fdatasync() for files with only i_size changes

2012-10-12T20:38:50+00:00

commit b71fc079b5d8f42b2a52743c8d2f1d35d655b1c5 upstream.

Code tracking when transaction needs to be committed on fdatasync(2) forgets
to handle a situation when only inode's i_size is changed. Thus in such
situations fdatasync(2) doesn't force transaction with new i_size to disk
and that can result in wrong i_size after a crash.

Fix the issue by updating inode's i_datasync_tid whenever its size is
updated.

Reported-by: Kristian Nielsen 
Signed-off-by: Jan Kara 
Signed-off-by: Greg Kroah-Hartman

ext4: fix potential deadlock in ext4_nonda_switch()

2012-10-12T20:38:49+00:00

commit 00d4e7362ed01987183e9528295de3213031309c upstream.

In ext4_nonda_switch(), if the file system is getting full we used to
call writeback_inodes_sb_if_idle().  The problem is that we can be
holding i_mutex already, and this causes a potential deadlock when
writeback_inodes_sb_if_idle() when it tries to take s_umount.  (See
lockdep output below).

As it turns out we don't need need to hold s_umount; the fact that we
are in the middle of the write(2) system call will keep the superblock
pinned.  Unfortunately writeback_inodes_sb() checks to make sure
s_umount is taken, and the VFS uses a different mechanism for making
sure the file system doesn't get unmounted out from under us.  The
simplest way of dealing with this is to just simply grab s_umount
using a trylock, and skip kicking the writeback flusher thread in the
very unlikely case that we can't take a read lock on s_umount without
blocking.

Also, we now check the cirteria for kicking the writeback thread
before we decide to whether to fall back to non-delayed writeback, so
if there are any outstanding delayed allocation writes, we try to get
them resolved as soon as possible.

   [ INFO: possible circular locking dependency detected ]
   3.6.0-rc1-00042-gce894ca #367 Not tainted
   -------------------------------------------------------
   dd/8298 is trying to acquire lock:
    (&type->s_umount_key#18){++++..}, at: [] writeback_inodes_sb_if_idle+0x28/0x46

   but task is already holding lock:
    (&sb->s_type->i_mutex_key#8){+.+...}, at: [] generic_file_aio_write+0x5f/0xd3

   which lock already depends on the new lock.

   2 locks held by dd/8298:
    #0:  (sb_writers#2){.+.+.+}, at: [] generic_file_aio_write+0x56/0xd3
    #1:  (&sb->s_type->i_mutex_key#8){+.+...}, at: [] generic_file_aio_write+0x5f/0xd3

   stack backtrace:
   Pid: 8298, comm: dd Not tainted 3.6.0-rc1-00042-gce894ca #367
   Call Trace:
    [] ? console_unlock+0x345/0x372
    [] print_circular_bug+0x190/0x19d
    [] __lock_acquire+0x86d/0xb6c
    [] ? mark_held_locks+0x5c/0x7b
    [] lock_acquire+0x66/0xb9
    [] ? writeback_inodes_sb_if_idle+0x28/0x46
    [] down_read+0x28/0x58
    [] ? writeback_inodes_sb_if_idle+0x28/0x46
    [] writeback_inodes_sb_if_idle+0x28/0x46
    [] ext4_nonda_switch+0xe1/0xf4
    [] ext4_da_write_begin+0x27/0x193
    [] generic_file_buffered_write+0xc8/0x1bb
    [] __generic_file_aio_write+0x1dd/0x205
    [] generic_file_aio_write+0x78/0xd3
    [] ext4_file_write+0x480/0x4a6
    [] ? __lock_acquire+0x41e/0xb6c
    [] ? sched_clock_cpu+0x11a/0x13e
    [] ? trace_hardirqs_off+0xb/0xd
    [] ? local_clock+0x37/0x4e
    [] do_sync_write+0x67/0x9d
    [] ? wait_on_retry_sync_kiocb+0x44/0x44
    [] vfs_write+0x7b/0xe6
    [] sys_write+0x3b/0x64
    [] syscall_call+0x7/0xb

Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: undo ext4_calc_metadata_amount if we fail to claim space

2012-08-09T15:31:41+00:00

commit 03179fe92318e7934c180d96f12eff2cb36ef7b6 upstream.

The function ext4_calc_metadata_amount() has side effects, although
it's not obvious from its function name.  So if we fail to claim
space, regardless of whether we retry to claim the space again, or
return an error, we need to undo these side effects.

Otherwise we can end up incorrectly calculating the number of metadata
blocks needed for the operation, which was responsible for an xfstests
failure for test #271 when using an ext2 file system with delalloc
enabled.

Reported-by: Brian Foster 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: don't let i_reserved_meta_blocks go negative

2012-08-09T15:31:41+00:00

commit 97795d2a5b8d3c8dc4365d4bd3404191840453ba upstream.

If we hit a condition where we have allocated metadata blocks that
were not appropriately reserved, we risk underflow of
ei->i_reserved_meta_blocks.  In turn, this can throw
sbi->s_dirtyclusters_counter significantly out of whack and undermine
the nondelalloc fallback logic in ext4_nonda_switch().  Warn if this
occurs and set i_allocated_meta_blocks to avoid this problem.

This condition is reproduced by xfstests 270 against ext2 with
delalloc enabled:

Mar 28 08:58:02 localhost kernel: [  171.526344] EXT4-fs (loop1): delayed block allocation failed for inode 14 at logical offset 64486 with max blocks 64 with error -28
Mar 28 08:58:02 localhost kernel: [  171.526346] EXT4-fs (loop1): This should not happen!! Data will be lost

270 ultimately fails with an inconsistent filesystem and requires an
fsck to repair.  The cause of the error is an underflow in
ext4_da_update_reserve_space() due to an unreserved meta block
allocation.

Signed-off-by: Brian Foster 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Greg Kroah-Hartman

ext4: do not mark superblock as dirty unnecessarily

2012-03-22T02:28:29+00:00

Commit a0375156ca1041574b5d47cc7e32f10b891151b0 cleaned up superblock
dirtying handling, but missed one place. This patch does what was
intended: if we have the journal, then we update the superblock
through the journal rather than doing this directly.

Signed-off-by: Artem Bityutskiy 
Signed-off-by: "Theodore Ts'o"

ext4: correct ext4_punch_hole return codes

2012-03-22T02:23:31+00:00

ext4_punch_hole returns -ENOTSUPP but it should be using -EOPNOTSUPP

Signed-off-by: Allison Henderson 
Signed-off-by: Lukas Czerner 
Signed-off-by: "Theodore Ts'o"

ext4: remove restrictive checks for EOFBLOCKS_FL

2012-03-22T01:47:55+00:00

We are going to remove the EOFBLOCKS_FL flag in the future, so this is
the first part of the removal. We can not remove it entirely just now,
since the e2fsck is still checking for it and it might cause headache to
some people. Instead, remove the restrictive checks now and the rest
later, when the new e2fsck code is out and common enough.

This is also needed because punch hole already breaks the EOFBLOCKS_FL
semantics, so it might cause the some troubles. So simply remove it.

Signed-off-by: Lukas Czerner 
Signed-off-by: "Theodore Ts'o"

ext4: change some printk() calls to use ext4_msg() instead

2012-03-20T03:41:49+00:00

Signed-off-by: "Theodore Ts'o"

ext4: remove trailing newlines from ext4_msg() and ext4_error() messages

2012-03-20T03:13:43+00:00

The functions ext4_msg() and ext4_error() already tack on a trailing
newline, so remove the unnecessary extra newline.

Signed-off-by: "Theodore Ts'o"

ext4: add no_printk argument validation, fix fallout

2012-03-20T03:11:43+00:00

Add argument validation to debug functions.
Use ##__VA_ARGS__.

Fix format and argument mismatches.

Signed-off-by: Joe Perches 
Signed-off-by: "Theodore Ts'o"