linux-toradex.git/fs/ext4/ext4_jbd2.c, branch v3.6.5

ext4: remove unnecessary argument from __ext4_handle_dirty_metadata()

2012-07-23T00:37:31+00:00

The '__ext4_handle_dirty_metadata()' does not need the 'now' argument
anymore and we can kill it.

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

ext4: remove unnecessary superblock dirtying

2012-07-23T00:33:31+00:00

This patch changes the 'ext4_handle_dirty_super()' function which
submits the superblock for I/O in the following cases:

1. When creating the first large file on a file system without
   EXT4_FEATURE_RO_COMPAT_LARGE_FILE feature.
2. When re-sizing the file-system.
3. When creating an xattr on a file-system without the
   EXT4_FEATURE_COMPAT_EXT_ATTR feature.

If the file-system has journal enabled, the superblock is written via
the journal. We do not modify this path.

If the file-system has no journal, this function, falls back to just
marking the superblock as dirty using the 's_dirt' superblock
flag. This means that it delays the actual superblock I/O submission
by 5 seconds (default setting).  Namely, the 'sync_supers()' kernel
thread will call 'ext4_write_super()' later and will actually submit
the superblock for I/O.

And this is the behavior this patch modifies: we stop using 's_dirt'
and just mark the superblock buffer as dirty right away. Indeed, all 3
cases above are extremely rare and it does not add any value to delay
the I/O submission for them.

Note: 'ext4_handle_dirty_super()' executes
'__ext4_handle_dirty_super()' with 'now = 0'. This patch basically
makes the 'now' argument unneeded and it will be deleted in one of the
next patches.

This patch also removes 's_dirt' condition on the unmount path because
we never set it anymore, so we should not test it.

Tested using xfstests for both journalled and non-journalled ext4.

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

ext4: calculate and verify superblock checksum

2012-04-29T22:29:10+00:00

Calculate and verify the superblock checksum.  Since the UUID and
block group number are embedded in each copy of the superblock, we
need only checksum the entire block.  Refactor some of the code to
eliminate open-coding of the checksum update call.

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

jbd2: add debugging information to jbd2_journal_dirty_metadata()

2011-09-04T14:18:14+00:00

Add debugging information in case jbd2_journal_dirty_metadata() is
called with a buffer_head which didn't have
jbd2_journal_get_write_access() called on it, or if the journal_head
has the wrong transaction in it.  In addition, return an error code.
This won't change anything for ocfs2, which will BUG_ON() the non-zero
exit code.

For ext4, the caller of this function is ext4_handle_dirty_metadata(),
and on seeing a non-zero return code, will call __ext4_journal_stop(),
which will print the function and line number of the (buggy) calling
function and abort the journal.  This will allow us to recover instead
of bug halting, which is better from a robustness and reliability
point of view.

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

ext4: remove unneeded ext4_journal_get_undo_access

2011-05-09T14:58:45+00:00

The block allocation code used to use jbd2_journal_get_undo_access as
a way to make changes that wouldn't show up until the commit took
place.  The new multi-block allocation code has a its own way of
preventing newly freed blocks from getting reused until the commit
takes place (it avoids updating the buddy bitmaps until the commit is
done), so we don't need to use jbd2_journal_get_undo_access(), which
has extra overhead compared to jbd2_journal_get_write_access().

There was one last vestigal use of ext4_journal_get_undo_access() in
ext4_add_groupblocks(); change it to use ext4_journal_get_write_access()
and then remove the ext4_journal_get_undo_access() support.

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

ext4: Save error information to the superblock for analysis

2010-07-27T15:56:03+00:00

Save number of file system errors, and the time function name, line
number, block number, and inode number of the first and most recent
errors reported on the file system in the superblock.

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

ext4: Pass line numbers to ext4_error() and friends

2010-07-27T15:56:40+00:00

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

ext4: Pass line number to ext4_journal_abort_handle()

2010-06-29T18:53:24+00:00

This allows the error messages to include the line number

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

ext4: clean up ext4_abort() so func is now implicit

2010-06-29T15:07:07+00:00

Use a macro definition for ext4_abort() to clean up the .c files a wee
bit.

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

ext4: Clean up s_dirt handling

2010-06-12T03:14:04+00:00

We don't need to set s_dirt in most of the ext4 code when journaling
is enabled.  In ext3/4 some of the summary statistics for # of free
inodes, blocks, and directories are calculated from the per-block
group statistics when the file system is mounted or unmounted.  As a
result the superblock doesn't have to be updated, either via the
journal or by setting s_dirt.  There are a few exceptions, most
notably when resizing the file system, where the superblock needs to
be modified --- and in that case it should be done as a journalled
operation if possible, and s_dirt set only in no-journal mode.

This patch will optimize out some unneeded disk writes when using ext4
with a journal.

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