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Date: Sun, 01 Jun 2008 14:06:53 -0700
From: Mingming Cao <cmm@...ibm.com>
To: Theodore Tso <tytso@....edu>
Cc: linux-ext4@...r.kernel.org
Subject: [PATCH] ext4: mballoc avoid use root reserved blocks for non root
allocation
ext4: mballoc avoid use root reserved blocks for non root allocation
From: Mingming Cao <cmm@...ibm.com>
mballoc allocation missed check for blocks reserved for root users. Add
ext4_has_free_blocks() check before allocation. Also modified
ext4_has_free_blocks() to support multiple block allocation request.
Signed-off-by: Mingming Cao <cmm@...ibm.com>
---
fs/ext4/balloc.c | 50 ++++++++++++++++++++++++++++++++------------------
fs/ext4/ext4.h | 2 ++
fs/ext4/mballoc.c | 7 ++++++-
3 files changed, 40 insertions(+), 19 deletions(-)
Index: linux-2.6.26-rc4/fs/ext4/mballoc.c
===================================================================
--- linux-2.6.26-rc4.orig/fs/ext4/mballoc.c 2008-06-01 13:13:53.000000000 -0700
+++ linux-2.6.26-rc4/fs/ext4/mballoc.c 2008-06-01 13:30:21.000000000 -0700
@@ -4038,6 +4038,12 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t
&(ar->len), errp);
return block;
}
+ ar->len = ext4_has_free_blocks(sbi, ar->len);
+
+ if (ar->len == 0) {
+ *errp = -ENOSPC;
+ return 0;
+ }
while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
ar->flags |= EXT4_MB_HINT_NOPREALLOC;
@@ -4066,7 +4072,6 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t
ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
if (!ext4_mb_use_preallocated(ac)) {
-
ac->ac_op = EXT4_MB_HISTORY_ALLOC;
ext4_mb_normalize_request(ac, ar);
repeat:
Index: linux-2.6.26-rc4/fs/ext4/balloc.c
===================================================================
--- linux-2.6.26-rc4.orig/fs/ext4/balloc.c 2008-06-01 13:07:44.000000000 -0700
+++ linux-2.6.26-rc4/fs/ext4/balloc.c 2008-06-01 13:30:21.000000000 -0700
@@ -1604,23 +1604,34 @@ out:
/**
* ext4_has_free_blocks()
- * @sbi: in-core super block structure.
+ * @sbi: in-core super block structure.
+ * @nblocks: number of neeed blocks
*
- * Check if filesystem has at least 1 free block available for allocation.
+ * Check if filesystem has free blocks available for allocation.
+ * Return the number of blocks avaible for allocation for this request
+ * On success, return nblocks
*/
-static int ext4_has_free_blocks(struct ext4_sb_info *sbi)
+ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
+ ext4_fsblk_t nblocks)
{
- ext4_fsblk_t free_blocks, root_blocks;
+ ext4_fsblk_t free_blocks;
+ ext4_fsblk_t root_blocks = 0;
free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter);
- root_blocks = ext4_r_blocks_count(sbi->s_es);
- if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) &&
+
+ if (!capable(CAP_SYS_RESOURCE) &&
sbi->s_resuid != current->fsuid &&
- (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) {
- return 0;
- }
- return 1;
-}
+ (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid)))
+ root_blocks = ext4_r_blocks_count(sbi->s_es);
+
+ if (free_blocks - root_blocks < FBC_BATCH)
+ free_blocks =
+ percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
+ if (free_blocks - root_blocks < nblocks )
+ return free_blocks -root_blocks;
+ return nblocks;
+ }
+
/**
* ext4_should_retry_alloc()
@@ -1636,7 +1647,7 @@ static int ext4_has_free_blocks(struct e
*/
int ext4_should_retry_alloc(struct super_block *sb, int *retries)
{
- if (!ext4_has_free_blocks(EXT4_SB(sb)) || (*retries)++ > 3)
+ if (!ext4_has_free_blocks(EXT4_SB(sb), 1) || (*retries)++ > 3)
return 0;
jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
@@ -1682,13 +1693,21 @@ ext4_fsblk_t ext4_new_blocks_old(handle_
ext4_group_t ngroups;
unsigned long num = *count;
- *errp = -ENOSPC;
sb = inode->i_sb;
if (!sb) {
+ *errp = -ENODEV;
printk("ext4_new_block: nonexistent device");
return 0;
}
+ sbi = EXT4_SB(sb);
+ *count = ext4_has_free_blocks(sbi, *count);
+ if (*count == 0) {
+ *errp = -ENOSPC;
+ return 0; /*return with ENOSPC error */
+ }
+ num = *count;
+
/*
* Check quota for allocation of this block.
*/
@@ -1712,11 +1731,6 @@ ext4_fsblk_t ext4_new_blocks_old(handle_
if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0))
my_rsv = &block_i->rsv_window_node;
- if (!ext4_has_free_blocks(sbi)) {
- *errp = -ENOSPC;
- goto out;
- }
-
/*
* First, test whether the goal block is free.
*/
Index: linux-2.6.26-rc4/fs/ext4/ext4.h
===================================================================
--- linux-2.6.26-rc4.orig/fs/ext4/ext4.h 2008-06-01 13:29:56.000000000 -0700
+++ linux-2.6.26-rc4/fs/ext4/ext4.h 2008-06-01 13:30:21.000000000 -0700
@@ -981,6 +981,8 @@ extern ext4_fsblk_t ext4_new_blocks(hand
unsigned long *count, int *errp);
extern ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
ext4_fsblk_t goal, unsigned long *count, int *errp);
+extern ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
+ ext4_fsblk_t nblocks);
extern void ext4_free_blocks (handle_t *handle, struct inode *inode,
ext4_fsblk_t block, unsigned long count, int metadata);
extern void ext4_free_blocks_sb (handle_t *handle, struct super_block *sb,
--
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