linux-stable.git/fs/ext4, branch v3.14.2

ext4: fix premature freeing of partial clusters split across leaf blocks

2014-04-27T00:19:06+00:00

commit ad6599ab3ac98a4474544086e048ce86ec15a4d1 upstream.

Xfstests generic/311 and shared/298 fail when run on a bigalloc file
system.  Kernel error messages produced during the tests report that
blocks to be freed are already on the to-be-freed list.  When e2fsck
is run at the end of the tests, it typically reports bad i_blocks and
bad free blocks counts.

The bug that causes these failures is located in ext4_ext_rm_leaf().
Code at the end of the function frees a partial cluster if it's not
shared with an extent remaining in the leaf.  However, if all the
extents in the leaf have been removed, the code dereferences an
invalid extent pointer (off the front of the leaf) when the check for
sharing is made.  This generally has the effect of unconditionally
freeing the partial cluster, which leads to the observed failures
when the partial cluster is shared with the last extent in the next
leaf.

Fix this by attempting to free the cluster only if extents remain in
the leaf.  Any remaining partial cluster will be freed if possible
when the next leaf is processed or when leaf removal is complete.

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

ext4: fix partial cluster handling for bigalloc file systems

2014-04-27T00:19:06+00:00

commit c06344939422bbd032ac967223a7863de57496b5 upstream.

Commit 9cb00419fa, which enables hole punching for bigalloc file
systems, exposed a bug introduced by commit 6ae06ff51e in an earlier
release.  When run on a bigalloc file system, xfstests generic/013, 068,
075, 083, 091, 100, 112, 127, 263, 269, and 270 fail with e2fsck errors
or cause kernel error messages indicating that previously freed blocks
are being freed again.

The latter commit optimizes the selection of the starting extent in
ext4_ext_rm_leaf() when hole punching by beginning with the extent
supplied in the path argument rather than with the last extent in the
leaf node (as is still done when truncating).  However, the code in
rm_leaf that initially sets partial_cluster to track cluster sharing on
extent boundaries is only guaranteed to run if rm_leaf starts with the
last node in the leaf.  Consequently, partial_cluster is not correctly
initialized when hole punching, and a cluster on the boundary of a
punched region that should be retained may instead be deallocated.

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

ext4: fix error return from ext4_ext_handle_uninitialized_extents()

2014-04-27T00:19:05+00:00

commit ce37c42919608e96ade3748fe23c3062a0a966c5 upstream.

Commit 3779473246 breaks the return of error codes from
ext4_ext_handle_uninitialized_extents() in ext4_ext_map_blocks().  A
portion of the patch assigns that function's signed integer return
value to an unsigned int.  Consequently, negatively valued error codes
are lost and can be treated as a bogus allocated block count.

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

ext4: atomically set inode->i_flags in ext4_set_inode_flags()

2014-03-31T00:02:06+00:00

Use cmpxchg() to atomically set i_flags instead of clearing out the
S_IMMUTABLE, S_APPEND, etc. flags and then setting them from the
EXT4_IMMUTABLE_FL, EXT4_APPEND_FL flags, since this opens up a race
where an immutable file has the immutable flag cleared for a brief
window of time.

Reported-by: John Sullivan 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

ext4: don't leave i_crtime.tv_sec uninitialized

2014-02-17T00:29:32+00:00

If the i_crtime field is not present in the inode, don't leave the
field uninitialized.

Fixes: ef7f38359 ("ext4: Add nanosecond timestamps")
Reported-by: Vegard Nossum 
Tested-by: Vegard Nossum 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@vger.kernel.org

ext4: fix online resize with a non-standard blocks per group setting

2014-02-16T03:42:25+00:00

The set_flexbg_block_bitmap() function assumed that the number of
blocks in a blockgroup was sb->blocksize * 8, which is normally true,
but not always!  Use EXT4_BLOCKS_PER_GROUP(sb) instead, to fix block
bitmap corruption after:

mke2fs -t ext4 -g 3072 -i 4096 /dev/vdd 1G
mount -t ext4 /dev/vdd /vdd
resize2fs /dev/vdd 8G

Signed-off-by: "Theodore Ts'o" 
Reported-by: Jon Bernard 
Cc: stable@vger.kernel.org

ext4: fix online resize with very large inode tables

2014-02-16T02:33:13+00:00

If a file system has a large number of inodes per block group, all of
the metadata blocks in a flex_bg may be larger than what can fit in a
single block group.  Unfortunately, ext4_alloc_group_tables() in
resize.c was never tested to see if it would handle this case
correctly, and there were a large number of bugs which caused the
following sequence to result in a BUG_ON:

kernel bug at fs/ext4/resize.c:409!
   ...
call trace:
 [] ext4_flex_group_add+0x1448/0x1830
 [] ext4_resize_fs+0x7b2/0xe80
 [] ext4_ioctl+0xbf0/0xf00
 [] do_vfs_ioctl+0x2dd/0x4b0
 [] ? final_putname+0x22/0x50
 [] sys_ioctl+0x81/0xa0
 [] system_call_fastpath+0x16/0x1b
code: c8 4c 89 df e8 41 96 f8 ff 44 89 e8 49 01 c4 44 29 6d d4 0
rip  [] set_flexbg_block_bitmap+0x171/0x180


This can be reproduced with the following command sequence:

   mke2fs -t ext4 -i 4096 /dev/vdd 1G
   mount -t ext4 /dev/vdd /vdd
   resize2fs /dev/vdd 8G

To fix this, we need to make sure the right thing happens when a block
group's inode table straddles two block groups, which means the
following bugs had to be fixed:

1) Not clearing the BLOCK_UNINIT flag in the second block group in
   ext4_alloc_group_tables --- the was proximate cause of the BUG_ON.

2) Incorrectly determining how many block groups contained contiguous
   free blocks in ext4_alloc_group_tables().

3) Incorrectly setting the start of the next block range to be marked
   in use after a discontinuity in setup_new_flex_group_blocks().

Signed-off-by: "Theodore Ts'o" 
Cc: stable@vger.kernel.org

ext4: don't try to modify s_flags if the the file system is read-only

2014-02-12T17:16:04+00:00

If an ext4 file system is created by some tool other than mke2fs
(perhaps by someone who has a pathalogical fear of the GPL) that
doesn't set one or the other of the EXT2_FLAGS_{UN}SIGNED_HASH flags,
and that file system is then mounted read-only, don't try to modify
the s_flags field.  Otherwise, if dm_verity is in use, the superblock
will change, causing an dm_verity failure.

Signed-off-by: "Theodore Ts'o" 
Cc: stable@vger.kernel.org

ext4: fix error paths in swap_inode_boot_loader()

2014-02-12T16:48:31+00:00

In swap_inode_boot_loader() we forgot to release ->i_mutex and resume
unlocked dio for inode and inode_bl if there is an error starting the
journal handle.  This commit fixes this issue.

Reported-by: Ahmed Tamrawi 
Cc: Andreas Dilger 
Cc: Dr. Tilmann Bubeck 
Signed-off-by: Zheng Liu 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@vger.kernel.org  # v3.10+

ext4: fix xfstest generic/299 block validity failures

2014-02-12T15:42:45+00:00

Commit a115f749c1 (ext4: remove wait for unwritten extent conversion from
ext4_truncate) exposed a bug in ext4_ext_handle_uninitialized_extents().
It can be triggered by xfstest generic/299 when run on a test file
system created without a journal.  This test continuously fallocates and
truncates files to which random dio/aio writes are simultaneously
performed by a separate process.  The test completes successfully, but
if the test filesystem is mounted with the block_validity option, a
warning message stating that a logical block has been mapped to an
illegal physical block is posted in the kernel log.

The bug occurs when an extent is being converted to the written state
by ext4_end_io_dio() and ext4_ext_handle_uninitialized_extents()
discovers a mapping for an existing uninitialized extent. Although it
sets EXT4_MAP_MAPPED in map->m_flags, it fails to set map->m_pblk to
the discovered physical block number.  Because map->m_pblk is not
otherwise initialized or set by this function or its callers, its
uninitialized value is returned to ext4_map_blocks(), where it is
stored as a bogus mapping in the extent status tree.

Since map->m_pblk can accidentally contain illegal values that are
larger than the physical size of the file system,  calls to
check_block_validity() in ext4_map_blocks() that are enabled if the
block_validity mount option is used can fail, resulting in the logged
warning message.

Signed-off-by: Eric Whitney 
Signed-off-by: "Theodore Ts'o" 
Cc: stable@vger.kernel.org  # 3.11+