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| author | Alexander V. Lukyanov <lav@netis.ru> | 2011-02-22 05:33:21 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2011-02-22 05:33:21 +0300 |
| commit | 5dbd571d875d73e087c1eeb3d840cfc653a97422 (patch) | |
| tree | dfad6885fad57fb45f3e1d37d3d2d56fd6c320b0 /fs/ext4/super.c | |
| parent | 7dc576158d7e5cdff3349f78598fdb4080536342 (diff) | |
| download | linux-5dbd571d875d73e087c1eeb3d840cfc653a97422.tar.xz | |
ext4: allow inode_readahead_blks=0 (linux-2.6.37)
I cannot disable inode-read-ahead feature of ext4 (on 2.6.37):
# echo 0 > /sys/fs/ext4/sda2/inode_readahead_blks
bash: echo: write error: Invalid argument
On a server with lots of small files and random access this read-ahead makes
performance worse, and I'd like to disable it. I work around this problem
by using value of 1, but it still reads an extra block.
This patch fixes the problem by checking for zero explicitly.
Signed-off-by: Alexander V. Lukyanov <lav@netis.ru>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index ef83457fd4ea..a1ac24b6a758 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1771,7 +1771,7 @@ set_qf_format: return 0; if (option < 0 || option > (1 << 30)) return 0; - if (!is_power_of_2(option)) { + if (option && !is_power_of_2(option)) { ext4_msg(sb, KERN_ERR, "EXT4-fs: inode_readahead_blks" " must be a power of 2"); @@ -2412,7 +2412,7 @@ static ssize_t inode_readahead_blks_store(struct ext4_attr *a, if (parse_strtoul(buf, 0x40000000, &t)) return -EINVAL; - if (!is_power_of_2(t)) + if (t && !is_power_of_2(t)) return -EINVAL; sbi->s_inode_readahead_blks = t; |