ext4: Signed arithmetic fix

This patch converts some usage of ext4_fsblk_t to s64.  This is needed
so that some of the sign conversion works as expected in if loops.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
index edef002..a425e78 100644 (file)
--- a/fs/ext4/balloc.c
+++ b/fs/ext4/balloc.c
@@ -1603,10 +1603,10 @@ out:
 }
 
 int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
-                                               ext4_fsblk_t nblocks)
+                                               s64 nblocks)
 {
        s64 free_blocks, dirty_blocks;
-       ext4_fsblk_t root_blocks = 0;
+       s64 root_blocks = 0;
        struct percpu_counter *fbc = &sbi->s_freeblocks_counter;
        struct percpu_counter *dbc = &sbi->s_dirtyblocks_counter;
 
@@ -1631,7 +1631,7 @@ int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
        /* Check whether we have space after
         * accounting for current dirty blocks
         */
-       if (free_blocks < ((s64)(root_blocks + nblocks) + dirty_blocks))
+       if (free_blocks < ((root_blocks + nblocks) + dirty_blocks))
                /* we don't have free space */
                return -ENOSPC;
 
@@ -1650,10 +1650,10 @@ int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
  * On success, return nblocks
  */
 ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
-                                               ext4_fsblk_t nblocks)
+                                               s64 nblocks)
 {
-       ext4_fsblk_t free_blocks, dirty_blocks;
-       ext4_fsblk_t root_blocks = 0;
+       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;
 
@@ -1667,14 +1667,15 @@ ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
 
        if (free_blocks - (nblocks + root_blocks + dirty_blocks) <
                                                EXT4_FREEBLOCKS_WATERMARK) {
-               free_blocks  = percpu_counter_sum_positive(fbc);
-               dirty_blocks = percpu_counter_sum_positive(dbc);
+               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 */
                return 0;
+
        if (free_blocks - (root_blocks + dirty_blocks) < nblocks)
-               return free_blocks - root_blocks;
+               return free_blocks - (root_blocks + dirty_blocks);
        return nblocks;
 }
 

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 0154c2d..e13b9de 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -983,10 +983,9 @@ 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 int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
 extern ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
-                                               ext4_fsblk_t nblocks);
+                                        s64 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,