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  1. 20 Aug, 2008 7 commits
    • Mingming Cao's avatar
      ext4: journal credit fix for the delayed allocation's writepages() function · 525f4ed8
      Mingming Cao authored 
      Previous delalloc writepages implementation started a new transaction
outside of a loop which called get_block() to do the block allocation.
Since we didn't know exactly how many blocks would need to be allocated,
the estimated journal credits required was very conservative and caused
many issues.

With the reworked delayed allocation, a new transaction is created for
each get_block(), thus we don't need to guess how many credits for the
multiple chunk of allocation.  We start every transaction with enough
credits for inserting a single exent.  When estimate the credits for
indirect blocks to allocate a chunk of blocks, we need to know the
number of data blocks to allocate.  We use the total number of reserved
delalloc datablocks; if that is too big, for non-extent files, we need
to limit the number of blocks to EXT4_MAX_TRANS_BLOCKS.

Code cleanup from Aneesh.
Signed-off-by: default avatarMingming Cao <cmm@us.ibm.com>
Reviewed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      525f4ed8
    • Aneesh Kumar K.V's avatar
      ext4: Rework the ext4_da_writepages() function · a1d6cc56
      Aneesh Kumar K.V authored 
      With the below changes we reserve credit needed to insert only one
extent resulting from a call to single get_block.  This makes sure we
don't take too much journal credits during writeout.  We also don't
limit the pages to write.  That means we loop through the dirty pages
building largest possible contiguous block request.  Then we issue a
single get_block request.  We may get less block that we requested.  If
so we would end up not mapping some of the buffer_heads.  That means
those buffer_heads are still marked delay.  Later in the writepage
callback via __mpage_writepage we redirty those pages.

We should also not limit/throttle wbc->nr_to_write in the filesystem
writepages callback. That cause wrong behaviour in
generic_sync_sb_inodes caused by wbc->nr_to_write being <= 0
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Reviewed-by: default avatarMingming Cao <cmm@us.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      a1d6cc56
    • Mingming Cao's avatar
      ext4: journal credits reservation fixes for DIO, fallocate · f3bd1f3f
      Mingming Cao authored 
      DIO and fallocate credit calculation is different than writepage, as
they do start a new journal right for each call to ext4_get_blocks_wrap().
This patch uses the helper function in DIO and fallocate case, passing
a flag indicating that the modified data are contigous thus could account
less indirect/index blocks.

This patch also fixed the journal credit reservation for direct I/O
(DIO).  Previously the estimated credits for DIO only was calculated for
non-extent files, which was not enough if the file is extent-based.

Also fixed was fallocate double-counting credits for modifying the the
superblock.
Signed-off-by: default avatarMingming Cao <cmm@us.ibm.com>
Reviewed-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      f3bd1f3f
    • Mingming Cao's avatar
      ext4: journal credits reservation fixes for extent file writepage · ee12b630
      Mingming Cao authored 
      This patch modified the writepage/write_begin credit calculation for
extent files, to use the credits caculation helper function.

The current calculation of how many index/leaf blocks should be
accounted is too conservetive, it always considered the worse case,
where the tree level is 5, and in the case of multiple chunk
allocations, it always assumed no blocks were dirtied in common across
the allocations. This path uses the accurate depth of the inode with
some extras to calculate the index blocks, and also less conservative in
the case of multiple allocation accounting.
Signed-off-by: default avatarMingming Cao <cmm@us.ibm.com>
Reviewed-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      ee12b630
    • Mingming Cao's avatar
      ext4: journal credits calulation cleanup and fix for non-extent writepage · a02908f1
      Mingming Cao authored 
      When considering how many journal credits are needed for modifying a
chunk of data, we need to account for the super block, inode block,
quota blocks and xattr block, indirect/index blocks, also, group bitmap
and group descriptor blocks for new allocation (including data and
indirect/index blocks). There are many places in ext4 do the calculation
on their own and often missed one or two meta blocks, and often they
assume single block allocation, and did not considering the multile
chunk of allocation case.

This patch is trying to cleanup current journal credit code, provides
some common helper funtion to calculate the journal credits, to be used
for writepage, writepages, DIO, fallocate, migration, defrag, and for
both nonextent and extent files.

This patch modified the writepage/write_begin credit caculation for
nonextent files, to use the new helper function. It also fixed the
problem that writepage on nonextent files did not consider the case
blocksize <pagesize, thus could possibelly need multiple block
allocation in a single transaction.
Signed-off-by: default avatarMingming Cao <cmm@us.ibm.com>
Reviewed-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      a02908f1
    • Eric Sandeen's avatar
      ext4: Fix bug where we return ENOSPC even though we have plenty of inodes · c001077f
      Eric Sandeen authored 
      The find_group_flex() function starts with best_flex as the
parent_fbg_group, which happens to have 0 inodes free.  Some of the
flex groups searched have free blocks and free inodes, but the
flex_freeb_ratio is < 10, so they're skipped.  Then when a group is
compared to the current "best" flex group, it does not have more free
blocks than "best", so it is skipped as well.

This continues until no flex group with free inodes is found which has
a proper ratio or which has more free blocks than the "best" group,
and we're left with a "best" group that has 0 inodes free, and we
return -ENOSPC.

We fix this by changing the logic so that if the current "best" flex
group has no inodes free, and the current one does have room, it is
promoted to the next "best."
Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      c001077f
    • Josef Bacik's avatar
      ext4: don't try to resize if there are no reserved gdt blocks left · 37609fd5
      Josef Bacik authored 
      When trying to resize an ext4 fs and you run out of reserved gdt blocks,
you get an error that doesn't actually tell you what went wrong, it just
says that the gdb it picked is not correct, which is the case since you
don't have any reserved gdt blocks left.  This patch adds a check to make
sure you have reserved gdt blocks to use, and if not prints out a more
relevant error.
Signed-off-by: default avatarJosef Bacik <jbacik@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Andreas Dilger <adilger@sun.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      37609fd5
  3. 16 Aug, 2008 1 commit
  5. 20 Aug, 2008 2 commits
  7. 14 Aug, 2008 1 commit
  9. 20 Aug, 2008 1 commit
  11. 13 Aug, 2008 1 commit
  13. 12 Aug, 2008 27 commits
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