linux.git/fs/ext4/super.c, branch v3.16

ext4: revert commit which was causing fs corruption after journal replays

2014-07-11T17:55:40+00:00

Commit 007649375f6af2 ("ext4: initialize multi-block allocator before
checking block descriptors") causes the block group descriptor's count
of the number of free blocks to become inconsistent with the number of
free blocks in the allocation bitmap.  This is a harmless form of fs
corruption, but it causes the kernel to potentially remount the file
system read-only, or to panic, depending on the file systems's error
behavior.

Thanks to Eric Whitney for his tireless work to reproduce and to find
the guilty commit.

Fixes: 007649375f6af2 ("ext4: initialize multi-block allocator before checking block descriptors"

Cc: stable@vger.kernel.org  # 3.15
Reported-by: David Jander 
Reported-by: Matteo Croce 
Tested-by: Eric Whitney 
Suggested-by: Eric Whitney 
Signed-off-by: Theodore Ts'o

ext4: disable synchronous transaction batching if max_batch_time==0

2014-07-05T23:18:22+00:00

The mount manpage says of the max_batch_time option,

	This optimization can be turned off entirely
	by setting max_batch_time to 0.

But the code doesn't do that.  So fix the code to do
that.

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

ext4: clarify error count warning messages

2014-07-05T22:40:52+00:00

Make it clear that values printed are times, and that it is error
since last fsck. Also add note about fsck version required.

Signed-off-by: Pavel Machek 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger 
Cc: stable@vger.kernel.org

ext4: add missing BUFFER_TRACE before ext4_journal_get_write_access

2014-05-13T02:06:43+00:00

Make them more consistently

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

ext4: remove unnecessary double parentheses

2014-05-12T16:55:07+00:00

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

ext4: make local functions static

2014-05-12T14:50:23+00:00

I have been running make namespacecheck to look for unneeded globals, and
found these in ext4.

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

ext4: find the group descriptors on a 1k-block bigalloc,meta_bg filesystem

2014-05-12T14:06:27+00:00

On a filesystem with a 1k block size, the group descriptors live in
block 2, not block 1.  If the filesystem has bigalloc,meta_bg set,
however, the calculation of the group descriptor table location does
not take this into account and returns the wrong block number.  Fix
the calculation to return the correct value for this case.

Signed-off-by: Darrick J. Wong 
Signed-off-by: "Theodore Ts'o"

ext4: add a new spinlock i_raw_lock to protect the ext4's raw inode

2014-04-21T18:37:55+00:00

To avoid potential data races, use a spinlock which protects the raw
(on-disk) inode.

Signed-off-by: "Theodore Ts'o" 
Reviewed-by: Jan Kara

ext4: rename uninitialized extents to unwritten

2014-04-21T03:45:47+00:00

Currently in ext4 there is quite a mess when it comes to naming
unwritten extents. Sometimes we call it uninitialized and sometimes we
refer to it as unwritten.

The right name for the extent which has been allocated but does not
contain any written data is _unwritten_. Other file systems are
using this name consistently, even the buffer head state refers to it as
unwritten. We need to fix this confusion in ext4.

This commit changes every reference to an uninitialized extent (meaning
allocated but unwritten) to unwritten extent. This includes comments,
function names and variable names. It even covers abbreviation of the
word uninitialized (such as uninit) and some misspellings.

This commit does not change any of the code paths at all. This has been
confirmed by comparing md5sums of the assembly code of each object file
after all the function names were stripped from it.

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

ext4: initialize multi-block allocator before checking block descriptors

2014-04-07T14:54:20+00:00

With EXT4FS_DEBUG ext4_count_free_clusters() will call
ext4_read_block_bitmap() without s_group_info initialized, so we need to
initialize multi-block allocator before.

And dependencies that must be solved, to allow this:
- multi-block allocator needs in group descriptors
- need to install s_op before initializing multi-block allocator,
  because in ext4_mb_init_backend() new inode is created.
- initialize number of group desc blocks (s_gdb_count) otherwise
  number of clusters returned by ext4_free_clusters_after_init() is not correct.
  (see ext4_bg_num_gdb_nometa())

Here is the stack backtrace:

(gdb) bt
 #0  ext4_get_group_info (group=0, sb=0xffff880079a10000) at ext4.h:2430
 #1  ext4_validate_block_bitmap (sb=sb@entry=0xffff880079a10000,
     desc=desc@entry=0xffff880056510000, block_group=block_group@entry=0,
     bh=bh@entry=0xffff88007bf2b2d8) at balloc.c:358
 #2  0xffffffff81232202 in ext4_wait_block_bitmap (sb=sb@entry=0xffff880079a10000,
     block_group=block_group@entry=0,
     bh=bh@entry=0xffff88007bf2b2d8) at balloc.c:476
 #3  0xffffffff81232eaf in ext4_read_block_bitmap (sb=sb@entry=0xffff880079a10000,
     block_group=block_group@entry=0) at balloc.c:489
 #4  0xffffffff81232fc0 in ext4_count_free_clusters (sb=sb@entry=0xffff880079a10000) at balloc.c:665
 #5  0xffffffff81259ffa in ext4_check_descriptors (first_not_zeroed=,
     sb=0xffff880079a10000) at super.c:2143
 #6  ext4_fill_super (sb=sb@entry=0xffff880079a10000, data=,
     data@entry=0x0 , silent=silent@entry=0) at super.c:3851
     ...

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