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  1. 18 Jul, 2007 5 commits
    • Amit Arora's avatar
      Change on-disk format to support 2^15 uninitialized extents · 749269fa
      Amit Arora authored 
      This change was suggested by Andreas Dilger. 
This patch changes the EXT_MAX_LEN value and extent code which marks/checks
uninitialized extents. With this change it will be possible to have
initialized extents with 2^15 blocks (earlier the max blocks we could have
was 2^15 - 1). This way we can have better extent-to-block alignment.
Now, maximum number of blocks we can have in an initialized extent is 2^15
and in an uninitialized extent is 2^15 - 1.
Signed-off-by: default avatarAmit Arora <aarora@in.ibm.com>
      749269fa
    • Amit Arora's avatar
      write support for preallocated blocks · 56055d3a
      Amit Arora authored 
      This patch adds write support to the uninitialized extents that get
created when a preallocation is done using fallocate(). It takes care of
splitting the extents into multiple (upto three) extents and merging the
new split extents with neighbouring ones, if possible.
Signed-off-by: default avatarAmit Arora <aarora@in.ibm.com>
      56055d3a
    • Amit Arora's avatar
      fallocate support in ext4 · a2df2a63
      Amit Arora authored 
      This patch implements ->fallocate() inode operation in ext4. With this
patch users of ext4 file systems will be able to use fallocate() system
call for persistent preallocation. Current implementation only supports
preallocation for regular files (directories not supported as of date)
with extent maps. This patch does not support block-mapped files currently.
Only FALLOC_ALLOCATE and FALLOC_RESV_SPACE modes are being supported as of
now.
Signed-off-by: default avatarAmit Arora <aarora@in.ibm.com>
      a2df2a63
    • Amit Arora's avatar
      sys_fallocate() implementation on i386, x86_64 and powerpc · 97ac7350
      Amit Arora authored 
      fallocate() is a new system call being proposed here which will allow
applications to preallocate space to any file(s) in a file system.
Each file system implementation that wants to use this feature will need
to support an inode operation called ->fallocate().
Applications can use this feature to avoid fragmentation to certain
level and thus get faster access speed. With preallocation, applications
also get a guarantee of space for particular file(s) - even if later the
the system becomes full.

Currently, glibc provides an interface called posix_fallocate() which
can be used for similar cause. Though this has the advantage of working
on all file systems, but it is quite slow (since it writes zeroes to
each block that has to be preallocated). Without a doubt, file systems
can do this more efficiently within the kernel, by implementing
the proposed fallocate() system call. It is expected that
posix_fallocate() will be modified to call this new system call first
and incase the kernel/filesystem does not implement it, it should fall
back to the current implementation of writing zeroes to the new blocks.
ToDos:
1. Implementation on other architectures (other than i386, x86_64,
   and ppc). Patches for s390(x) and ia64 are already available from
   previous posts, but it was decided that they should be added later
   once fallocate is in the mainline. Hence not including those patches
   in this take.
2. Changes to glibc,
   a) to support fallocate() system call
   b) to make posix_fallocate() and posix_fallocate64() call fallocate()
Signed-off-by: default avatarAmit Arora <aarora@in.ibm.com>
      97ac7350
    • Paul Mundt's avatar
      slob: Kill off duplicate kzalloc() definition. · cb32da04
      Paul Mundt authored 
      With the slab zeroing allocations cleanups Christoph stubbed in a generic
kzalloc(), which was missed on SLOB. Follow the SLAB/SLUB changes and
kill off the __kzalloc() wrapper that SLOB was using.
Reported-by: default avatarJan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      cb32da04
  3. 17 Jul, 2007 35 commits
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