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| author | Eric Sandeen <sandeen@redhat.com> | 2008-10-28 00:08:17 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2008-10-28 00:08:17 -0400 |
| commit | a996031c87e093017c0763326a08896a3a4817f4 (patch) | |
| tree | 74550b7108b1b1fd87393801de56bd9e1e8b1012 /fs | |
| parent | 8c3bf8a01c005385e9be0bc992e10abfb355278c (diff) | |
| download | op-kernel-dev-a996031c87e093017c0763326a08896a3a4817f4.zip op-kernel-dev-a996031c87e093017c0763326a08896a3a4817f4.tar.gz | |
delay capable() check in ext4_has_free_blocks()
As reported by Eric Paris, the capable() check in ext4_has_free_blocks()
sometimes causes SELinux denials.
We can rearrange the logic so that we only try to use the root-reserved
blocks when necessary, and even then we can move the capable() test
to last, to avoid the check most of the time.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext4/balloc.c | 26 |
1 files changed, 14 insertions, 12 deletions
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index e28203e..d2003cd 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -599,18 +599,13 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode, */ int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks) { - s64 free_blocks, dirty_blocks; - s64 root_blocks = 0; + s64 free_blocks, dirty_blocks, root_blocks; struct percpu_counter *fbc = &sbi->s_freeblocks_counter; struct percpu_counter *dbc = &sbi->s_dirtyblocks_counter; free_blocks = percpu_counter_read_positive(fbc); dirty_blocks = percpu_counter_read_positive(dbc); - - if (!capable(CAP_SYS_RESOURCE) && - sbi->s_resuid != current->fsuid && - (sbi->s_resgid == 0 || !in_group_p(sbi->s_resgid))) - root_blocks = ext4_r_blocks_count(sbi->s_es); + root_blocks = ext4_r_blocks_count(sbi->s_es); if (free_blocks - (nblocks + root_blocks + dirty_blocks) < EXT4_FREEBLOCKS_WATERMARK) { @@ -623,13 +618,20 @@ int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks) } } /* Check whether we have space after - * accounting for current dirty blocks + * accounting for current dirty blocks & root reserved blocks. */ - if (free_blocks < ((root_blocks + nblocks) + dirty_blocks)) - /* we don't have free space */ - return 0; + if (free_blocks >= ((root_blocks + nblocks) + dirty_blocks)) + return 1; - return 1; + /* Hm, nope. Are (enough) root reserved blocks available? */ + if (sbi->s_resuid == current->fsuid || + ((sbi->s_resgid != 0) && in_group_p(sbi->s_resgid)) || + capable(CAP_SYS_RESOURCE)) { + if (free_blocks >= (nblocks + dirty_blocks)) + return 1; + } + + return 0; } int ext4_claim_free_blocks(struct ext4_sb_info *sbi, |
