From a996031c87e093017c0763326a08896a3a4817f4 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Tue, 28 Oct 2008 00:08:17 -0400 Subject: 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 Reviewed-by: Mingming Cao Signed-off-by: "Theodore Ts'o" --- fs/ext4/balloc.c | 26 ++++++++++++++------------ 1 file changed, 14 insertions(+), 12 deletions(-) (limited to 'fs/ext4') diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index e28203ec45b..d2003cdc36a 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, -- cgit v1.2.3