From 8c3bf8a01c005385e9be0bc992e10abfb355278c Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@redhat.com>
Date: Tue, 28 Oct 2008 00:08:12 -0400
Subject: merge ext4_claim_free_blocks & ext4_has_free_blocks
Mingming pointed out that ext4_claim_free_blocks & ext4_has_free_blocks
are largely cut & pasted; they can be collapsed/merged as follows.
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>
---
fs/ext4/balloc.c | 57 ++++++++++++++++----------------------------------------
1 file changed, 16 insertions(+), 41 deletions(-)
(limited to 'fs/ext4/balloc.c')
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index b9821be709bd..e28203ec45bd 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -589,8 +589,15 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
return;
}
-int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
- s64 nblocks)
+/**
+ * ext4_has_free_blocks()
+ * @sbi: in-core super block structure.
+ * @nblocks: number of needed blocks
+ *
+ * Check if filesystem has nblocks free & available for allocation.
+ * On success return 1, return 0 on failure.
+ */
+int ext4_has_free_blocks(struct ext4_sb_info *sbi, s64 nblocks)
{
s64 free_blocks, dirty_blocks;
s64 root_blocks = 0;
@@ -620,53 +627,21 @@ int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
*/
if (free_blocks < ((root_blocks + nblocks) + dirty_blocks))
/* we don't have free space */
- return -ENOSPC;
+ return 0;
- /* Add the blocks to nblocks */
- percpu_counter_add(dbc, nblocks);
- return 0;
+ return 1;
}
-/**
- * ext4_has_free_blocks()
- * @sbi: in-core super block structure.
- * @nblocks: number of neeed blocks
- *
- * Check if filesystem has free blocks available for allocation.
- * Return the number of blocks avaible for allocation for this request
- * On success, return nblocks
- */
-ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
+int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
s64 nblocks)
{
- s64 free_blocks, dirty_blocks;
- s64 root_blocks = 0;
- 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);
-
- if (free_blocks - (nblocks + root_blocks + dirty_blocks) <
- EXT4_FREEBLOCKS_WATERMARK) {
- free_blocks = percpu_counter_sum(fbc);
- dirty_blocks = percpu_counter_sum(dbc);
- }
- if (free_blocks <= (root_blocks + dirty_blocks))
- /* we don't have free space */
+ if (ext4_has_free_blocks(sbi, nblocks)) {
+ percpu_counter_add(&sbi->s_dirtyblocks_counter, nblocks);
return 0;
-
- if (free_blocks - (root_blocks + dirty_blocks) < nblocks)
- return free_blocks - (root_blocks + dirty_blocks);
- return nblocks;
+ } else
+ return -ENOSPC;
}
-
/**
* ext4_should_retry_alloc()
* @sb: super block
--
cgit v1.2.3
From a996031c87e093017c0763326a08896a3a4817f4 Mon Sep 17 00:00:00 2001
From: Eric Sandeen <sandeen@redhat.com>
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 <sandeen@redhat.com>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
---
fs/ext4/balloc.c | 26 ++++++++++++++------------
1 file changed, 14 insertions(+), 12 deletions(-)
(limited to 'fs/ext4/balloc.c')
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index e28203ec45bd..d2003cdc36aa 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