diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index 58005c01abb8bc96c708e5710ac08582cfcc8acc..1707850301d6b77a4ee5da629d51b6fc37299dc6 100644
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -1602,6 +1602,32 @@ ext4_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle,
return ret;
}
+int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
+ ext4_fsblk_t nblocks)
+{
+ s64 free_blocks;
+ ext4_fsblk_t root_blocks = 0;
+ struct percpu_counter *fbc = &sbi->s_freeblocks_counter;
+
+ free_blocks = percpu_counter_read(fbc);
+
+ 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) < EXT4_FREEBLOCKS_WATERMARK)
+ free_blocks = percpu_counter_sum(&sbi->s_freeblocks_counter);
+
+ if (free_blocks < (root_blocks + nblocks))
+ /* we don't have free space */
+ return -ENOSPC;
+
+ /* reduce fs free blocks counter */
+ percpu_counter_sub(fbc, nblocks);
+ return 0;
+}
+
/**
* ext4_has_free_blocks()
* @sbi: in-core super block structure.
@@ -1623,18 +1649,17 @@ ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
sbi->s_resuid != current->fsuid &&
(sbi->s_resgid == 0 || !in_group_p(sbi->s_resgid)))
root_blocks = ext4_r_blocks_count(sbi->s_es);
-#ifdef CONFIG_SMP
- if (free_blocks - root_blocks < FBC_BATCH)
- free_blocks =
- percpu_counter_sum(&sbi->s_freeblocks_counter);
-#endif
+
+ if (free_blocks - (nblocks + root_blocks) < EXT4_FREEBLOCKS_WATERMARK)
+ free_blocks = percpu_counter_sum_positive(&sbi->s_freeblocks_counter);
+
if (free_blocks <= root_blocks)
/* we don't have free space */
return 0;
if (free_blocks - root_blocks < nblocks)
return free_blocks - root_blocks;
return nblocks;
- }
+}
/**
@@ -1713,14 +1738,11 @@ ext4_fsblk_t ext4_old_new_blocks(handle_t *handle, struct inode *inode,
/*
* With delalloc we already reserved the blocks
*/
- *count = ext4_has_free_blocks(sbi, *count);
- }
- if (*count == 0) {
- *errp = -ENOSPC;
- return 0; /*return with ENOSPC error */
+ if (ext4_claim_free_blocks(sbi, *count)) {
+ *errp = -ENOSPC;
+ return 0; /*return with ENOSPC error */
+ }
}
- num = *count;
-
/*
* Check quota for allocation of this block.
*/
@@ -1915,9 +1937,13 @@ ext4_fsblk_t ext4_old_new_blocks(handle_t *handle, struct inode *inode,
le16_add_cpu(&gdp->bg_free_blocks_count, -num);
gdp->bg_checksum = ext4_group_desc_csum(sbi, group_no, gdp);
spin_unlock(sb_bgl_lock(sbi, group_no));
- if (!EXT4_I(inode)->i_delalloc_reserved_flag)
- percpu_counter_sub(&sbi->s_freeblocks_counter, num);
-
+ if (!EXT4_I(inode)->i_delalloc_reserved_flag && (*count != num)) {
+ /*
+ * we allocated less blocks than we
+ * claimed. Add the difference back.
+ */
+ percpu_counter_add(&sbi->s_freeblocks_counter, *count - num);
+ }
if (sbi->s_log_groups_per_flex) {
ext4_group_t flex_group = ext4_flex_group(sbi, group_no);
spin_lock(sb_bgl_lock(sbi, flex_group));
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 8c701318844dafda864d9e74f66b34a7b454ee58..0154c2d0b242957fd604b725307cd46c69c6c5b9 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -983,6 +983,8 @@ extern ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode,
unsigned long *count, int *errp);
extern ext4_fsblk_t ext4_old_new_blocks(handle_t *handle, struct inode *inode,
ext4_fsblk_t goal, unsigned long *count, int *errp);
+extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
+ ext4_fsblk_t nblocks);
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,
@@ -1207,6 +1209,17 @@ do { \
__ext4_std_error((sb), __func__, (errno)); \
} while (0)
+#ifdef CONFIG_SMP
+/* Each CPU can accumulate FBC_BATCH blocks in their local
+ * counters. So we need to make sure we have free blocks more
+ * than FBC_BATCH * nr_cpu_ids. Also add a window of 4 times.
+ */
+#define EXT4_FREEBLOCKS_WATERMARK (4 * (FBC_BATCH * nr_cpu_ids))
+#else
+#define EXT4_FREEBLOCKS_WATERMARK 0
+#endif
+
+
/*
* Inodes and files operations
*/
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b6fa0c4087e9adb3cee4eed99f443b5121b9c903..b778d5a33ea7c32f1fdebfce5c0be300f5e5b1de 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1537,13 +1537,10 @@ static int ext4_da_reserve_space(struct inode *inode, int nrblocks)
md_needed = mdblocks - EXT4_I(inode)->i_reserved_meta_blocks;
total = md_needed + nrblocks;
- if (ext4_has_free_blocks(sbi, total) < total) {
+ if (ext4_claim_free_blocks(sbi, total)) {
spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
return -ENOSPC;
}
- /* reduce fs free blocks counter */
- percpu_counter_sub(&sbi->s_freeblocks_counter, total);
-
EXT4_I(inode)->i_reserved_data_blocks += nrblocks;
EXT4_I(inode)->i_reserved_meta_blocks = mdblocks;
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 0db2ccfa0dad0491ed1d099ec956556ad1b966f3..2c10b5058a8da7d4604173310155cfb0427bc639 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2975,9 +2975,15 @@ ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
* at write_begin() time for delayed allocation
* do not double accounting
*/
- if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
- percpu_counter_sub(&sbi->s_freeblocks_counter,
- ac->ac_b_ex.fe_len);
+ if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED) &&
+ ac->ac_o_ex.fe_len != ac->ac_b_ex.fe_len) {
+ /*
+ * we allocated less blocks than we calimed
+ * Add the difference back
+ */
+ percpu_counter_add(&sbi->s_freeblocks_counter,
+ ac->ac_o_ex.fe_len - ac->ac_b_ex.fe_len);
+ }
if (sbi->s_log_groups_per_flex) {
ext4_group_t flex_group = ext4_flex_group(sbi,
@@ -4389,14 +4395,11 @@ ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
/*
* With delalloc we already reserved the blocks
*/
- ar->len = ext4_has_free_blocks(sbi, ar->len);
- }
-
- if (ar->len == 0) {
- *errp = -ENOSPC;
- return 0;
+ if (ext4_claim_free_blocks(sbi, ar->len)) {
+ *errp = -ENOSPC;
+ return 0;
+ }
}
-
while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
ar->flags |= EXT4_MB_HINT_NOPREALLOC;
ar->len--;