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  1. 28 Apr, 2009 1 commit
    • Theodore Ts'o's avatar
      ext4: Fallback to vmalloc if kmalloc can't allocate s_flex_groups array · c5ca7c76
      Theodore Ts'o authored 
      For very large filesystems, the s_flex_groups array can get quite big.
For example, a filesystem that can be resized up to 16TB will have
8192 flex groups (assuming the default flex_bg size of 16), so the
array is 96k, which is *very* marginal for kmalloc().  On the other
hand, a 160GB filesystem without the resize_inode feature will only
require 960 bytes.  So we try to allocate the array first using
kmalloc(), and if that fails, we'll try to use vmalloc() instead.
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      c5ca7c76
  3. 12 May, 2009 2 commits
    • Aneesh Kumar K.V's avatar
      ext4: Mark the unwritten buffer_head as mapped during write_begin · 29fa89d0
      Aneesh Kumar K.V authored 
      Setting BH_Unwritten buffer_heads as BH_Mapped avoids multiple
(unnecessary) calls to get_block() during the call to the write(2)
system call.  Setting BH_Unwritten buffer heads as BH_Mapped requires
that the writepages() functions can handle BH_Unwritten buffer_heads.

After this commit, things work as follows:

ext4_ext_get_block() returns unmapped, unwritten, buffer head when
called with create = 0 for prealloc space. This makes sure we handle
the read path and non-delayed allocation case correctly.  Even though
the buffer head is marked unmapped we have valid b_blocknr and b_bdev
values in the buffer_head.

ext4_da_get_block_prep() called for block resrevation will now return
mapped, unwritten, new buffer_head for prealloc space. This avoids
multiple calls to get_block() for write to same offset. By making such
buffers as BH_New, we also assure that sub-block zeroing of buffered
writes happens correctly.
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      29fa89d0
    • Aneesh Kumar K.V's avatar
      vfs: Add BUG_ON for delayed and unwritten flags in submit_bh() · 8fb0e342
      Aneesh Kumar K.V authored 
      The BH_Delay and BH_Unwritten flags should never leak out to
submit_bh().  So add some BUG_ON() checks to submit_bh so we can get a
stack trace and determine how and why this might have happened.

(Note that only XFS and ext4 use these buffer head flags, and XFS does
not use submit_bh().  So this patch should only modify behavior for
ext4.)
Signed-off-by: default avatarAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Cc: linux-fsdevel@vger.kernel.org
      8fb0e342
  5. 13 May, 2009 1 commit
  7. 03 Jun, 2009 2 commits
  9. 02 Jun, 2009 11 commits
  11. 01 Jun, 2009 12 commits
  13. 31 May, 2009 1 commit
  15. 30 May, 2009 10 commits
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