ext4: Make sure all the block allocation paths reserve blocks

[linux-2.6-omap-h63xx.git] / fs / ext4 / ext4.h

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 8c701318844dafda864d9e74f66b34a7b454ee58..0154c2d0b242957fd604b725307cd46c69c6c5b9 100644 (file)
--- 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
  */