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-rw-r--r--fs/fat/cache.c79
1 files changed, 54 insertions, 25 deletions
diff --git a/fs/fat/cache.c b/fs/fat/cache.c
index 93fc622..5d38492 100644
--- a/fs/fat/cache.c
+++ b/fs/fat/cache.c
@@ -301,15 +301,59 @@ static int fat_bmap_cluster(struct inode *inode, int cluster)
return dclus;
}
-int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
- unsigned long *mapped_blocks, int create)
+int fat_get_mapped_cluster(struct inode *inode, sector_t sector,
+ sector_t last_block,
+ unsigned long *mapped_blocks, sector_t *bmap)
{
struct super_block *sb = inode->i_sb;
struct msdos_sb_info *sbi = MSDOS_SB(sb);
+ int cluster, offset;
+
+ cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits);
+ offset = sector & (sbi->sec_per_clus - 1);
+ cluster = fat_bmap_cluster(inode, cluster);
+ if (cluster < 0)
+ return cluster;
+ else if (cluster) {
+ *bmap = fat_clus_to_blknr(sbi, cluster) + offset;
+ *mapped_blocks = sbi->sec_per_clus - offset;
+ if (*mapped_blocks > last_block - sector)
+ *mapped_blocks = last_block - sector;
+ }
+
+ return 0;
+}
+
+static int is_exceed_eof(struct inode *inode, sector_t sector,
+ sector_t *last_block, int create)
+{
+ struct super_block *sb = inode->i_sb;
const unsigned long blocksize = sb->s_blocksize;
const unsigned char blocksize_bits = sb->s_blocksize_bits;
+
+ *last_block = (i_size_read(inode) + (blocksize - 1)) >> blocksize_bits;
+ if (sector >= *last_block) {
+ if (!create)
+ return 1;
+
+ /*
+ * ->mmu_private can access on only allocation path.
+ * (caller must hold ->i_mutex)
+ */
+ *last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1))
+ >> blocksize_bits;
+ if (sector >= *last_block)
+ return 1;
+ }
+
+ return 0;
+}
+
+int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
+ unsigned long *mapped_blocks, int create, bool from_bmap)
+{
+ struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
sector_t last_block;
- int cluster, offset;
*phys = 0;
*mapped_blocks = 0;
@@ -321,31 +365,16 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
return 0;
}
- last_block = (i_size_read(inode) + (blocksize - 1)) >> blocksize_bits;
- if (sector >= last_block) {
- if (!create)
+ if (!from_bmap) {
+ if (is_exceed_eof(inode, sector, &last_block, create))
return 0;
-
- /*
- * ->mmu_private can access on only allocation path.
- * (caller must hold ->i_mutex)
- */
- last_block = (MSDOS_I(inode)->mmu_private + (blocksize - 1))
- >> blocksize_bits;
+ } else {
+ last_block = inode->i_blocks >>
+ (inode->i_sb->s_blocksize_bits - 9);
if (sector >= last_block)
return 0;
}
- cluster = sector >> (sbi->cluster_bits - sb->s_blocksize_bits);
- offset = sector & (sbi->sec_per_clus - 1);
- cluster = fat_bmap_cluster(inode, cluster);
- if (cluster < 0)
- return cluster;
- else if (cluster) {
- *phys = fat_clus_to_blknr(sbi, cluster) + offset;
- *mapped_blocks = sbi->sec_per_clus - offset;
- if (*mapped_blocks > last_block - sector)
- *mapped_blocks = last_block - sector;
- }
- return 0;
+ return fat_get_mapped_cluster(inode, sector, last_block, mapped_blocks,
+ phys);
}
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