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| author | Greg Harm <gharm@google.com> | 2011-10-31 18:41:47 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-10-31 18:41:47 -0400 |
| commit | 3c6fe77017bc6ce489f231c35fed3220b6691836 (patch) | |
| tree | b3ca4d00dcecaf146361fef04afd8135ff370a07 | |
| parent | 4af835089984ce9e24c44a51be64c5524788e973 (diff) | |
| download | linux-stable-3c6fe77017bc6ce489f231c35fed3220b6691836.tar.gz linux-stable-3c6fe77017bc6ce489f231c35fed3220b6691836.tar.bz2 linux-stable-3c6fe77017bc6ce489f231c35fed3220b6691836.zip | |
ext4: Don't normalize an falloc request if it can fit in 1 extent.
If an fallocate request fits in EXT_UNINIT_MAX_LEN, then set the
EXT4_GET_BLOCKS_NO_NORMALIZE flag. For larger fallocate requests,
let mballoc.c normalize the request.
This fixes a problem where large requests were being split into
non-contiguous extents due to commit 556b27abf73: ext4: do not
normalize block requests from fallocate.
Testing:
*) Checked that 8.x MB falloc'ed files are still laid down next to
each other (contiguously).
*) Checked that the maximum size extent (127.9MB) is allocated as 1
extent.
*) Checked that a 1GB file is somewhat contiguous (often 5-6
non-contiguous extents now).
*) Checked that a 120MB file can still be falloc'ed even if there are
no single extents large enough to hold it.
Signed-off-by: Greg Harm <gharm@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/extents.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index a5c8caaaa099..2798945a1920 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4337,10 +4337,16 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len) trace_ext4_fallocate_exit(inode, offset, max_blocks, ret); return ret; } - flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT | - EXT4_GET_BLOCKS_NO_NORMALIZE; + flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT; if (mode & FALLOC_FL_KEEP_SIZE) flags |= EXT4_GET_BLOCKS_KEEP_SIZE; + /* + * Don't normalize the request if it can fit in one extent so + * that it doesn't get unnecessarily split into multiple + * extents. + */ + if (len <= EXT_UNINIT_MAX_LEN << blkbits) + flags |= EXT4_GET_BLOCKS_NO_NORMALIZE; retry: while (ret >= 0 && ret < max_blocks) { map.m_lblk = map.m_lblk + ret; |