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| author | Bob Peterson <rpeterso@redhat.com> | 2008-01-11 13:44:50 -0600 |
|---|---|---|
| committer | Steven Whitehouse <swhiteho@redhat.com> | 2008-01-25 08:19:03 +0000 |
| commit | 05220535196d413db434527a3edcba79b7187df8 (patch) | |
| tree | 5811b6f1caeac55102afb993f0b1538bbe9ed2b8 /fs/gfs2/bmap.c | |
| parent | 598278bd4808ed81b0e6fa445458a7d549f72a32 (diff) | |
| download | blackbird-obmc-linux-05220535196d413db434527a3edcba79b7187df8.tar.gz blackbird-obmc-linux-05220535196d413db434527a3edcba79b7187df8.zip | |
[GFS2] gfs2_alloc_required performance
This is a small I/O performance enhancement to gfs2. (Actually, it is a rework of
an earlier version I got wrong). The idea here is to check if the write extends
past the last block in the file. If so, the function can save itself a lot of
time and trouble because it knows an allocate will be required. Benchmarks like
iozone should see better performance.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/bmap.c')
| -rw-r--r-- | fs/gfs2/bmap.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 73dfad70de66..4356cc2fb3f5 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1224,6 +1224,11 @@ int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, unsigned int shift = sdp->sd_sb.sb_bsize_shift; lblock = offset >> shift; lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift; + if (lblock_stop > ip->i_di.di_blocks) { /* writing past the + last block */ + *alloc_required = 1; + return 0; + } } for (; lblock < lblock_stop; lblock += extlen) { |
