fat: skip cluster allocation on fallocated region

Skip new cluster allocation after checking i_blocks limit in _fat_get_block,
because the blocks are already allocated in fallocated region.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index a6d41fb36a98b880842ea09480a8361f2036d641..0e5bc19c67b17647b672e58adcbb6cb9063e5407 100644 (file)
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -115,7 +115,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
        struct super_block *sb = inode->i_sb;
        struct msdos_sb_info *sbi = MSDOS_SB(sb);
        unsigned long mapped_blocks;
-       sector_t phys;
+       sector_t phys, last_block;
        int err, offset;
 
        err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
@@ -135,8 +135,14 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
                return -EIO;
        }
 
+       last_block = inode->i_blocks >> (sb->s_blocksize_bits - 9);
        offset = (unsigned long)iblock & (sbi->sec_per_clus - 1);
-       if (!offset) {
+       /*
+        * allocate a cluster according to the following.
+        * 1) no more available blocks
+        * 2) not part of fallocate region
+        */
+       if (!offset && !(iblock < last_block)) {
                /* TODO: multiple cluster allocation would be desirable. */
                err = fat_add_cluster(inode);
                if (err)