return dclus;
}
+static 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;
+}
+
int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
unsigned long *mapped_blocks, int create)
{
const unsigned long blocksize = sb->s_blocksize;
const unsigned char blocksize_bits = sb->s_blocksize_bits;
sector_t last_block;
- int cluster, offset;
*phys = 0;
*mapped_blocks = 0;
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);
+}
+
+int fat_bmap2(struct inode *inode, sector_t sector,
+ unsigned long *mapped_blocks, struct buffer_head *bh_result,
+ int create, sector_t *bmap)
+{
+ struct super_block *sb = inode->i_sb;
+ sector_t last_block;
+ const unsigned long blocksize = sb->s_blocksize;
+ const unsigned char blocksize_bits = sb->s_blocksize_bits;
+
+ BUG_ON(create != 0);
+
+ *bmap = 0;
+ *mapped_blocks = 0;
+
+ last_block = (MSDOS_I(inode)->i_disksize + (blocksize - 1))
+ >> blocksize_bits;
+
+ if (sector >= last_block)
+ return 0;
+
+ return fat_get_mapped_cluster(inode, sector, last_block, mapped_blocks,
+ bmap);
}
int *fclus, int *dclus);
extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
unsigned long *mapped_blocks, int create);
+extern int fat_bmap2(struct inode *inode, sector_t sector,
+ unsigned long *mapped_blocks,
+ struct buffer_head *bh_result, int create, sector_t *bmap);
/* fat/dir.c */
extern const struct file_operations fat_dir_operations;
return ret;
}
+static int fat_get_block_bmap(struct inode *inode, sector_t iblock,
+ struct buffer_head *bh_result, int create)
+{
+ struct super_block *sb = inode->i_sb;
+ unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
+ int err;
+ sector_t bmap;
+ unsigned long mapped_blocks;
+
+ err = fat_bmap2(inode, iblock, &mapped_blocks, bh_result, create,
+ &bmap);
+ if (err)
+ return err;
+
+ if (bmap) {
+ map_bh(bh_result, sb, bmap);
+ max_blocks = min(mapped_blocks, max_blocks);
+ }
+
+ bh_result->b_size = max_blocks << sb->s_blocksize_bits;
+ return 0;
+}
+
static sector_t _fat_bmap(struct address_space *mapping, sector_t block)
{
sector_t blocknr;
/* fat_get_cluster() assumes the requested blocknr isn't truncated. */
down_read(&MSDOS_I(mapping->host)->truncate_lock);
- blocknr = generic_block_bmap(mapping, block, fat_get_block);
+ blocknr = generic_block_bmap(mapping, block, fat_get_block_bmap);
up_read(&MSDOS_I(mapping->host)->truncate_lock);
return blocknr;