fat: permit to return phy block number by fibmap in fallocated region

Make the fibmap call return the proper physical block number for any
offset request in the fallocated range.

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/cache.c b/fs/fat/cache.c
index 93fc62232ec21e795efc938edad43a22d55cac52..5d384921524d9722c96cd14c9fdcf0a3aab05851 100644 (file)
--- 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);
 }

diff --git a/fs/fat/dir.c b/fs/fat/dir.c
index 8b2127ffb226cca2ece880d41fd756624c5d3118..7def96caec5f7fc4abd82e51746bce4dce1f30ee 100644 (file)
--- a/fs/fat/dir.c
+++ b/fs/fat/dir.c
@@ -91,7 +91,7 @@ next:
 
        *bh = NULL;
        iblock = *pos >> sb->s_blocksize_bits;
-       err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0);
+       err = fat_bmap(dir, iblock, &phys, &mapped_blocks, 0, false);
        if (err || !phys)
                return -1;      /* beyond EOF or error */
 

diff --git a/fs/fat/fat.h b/fs/fat/fat.h
index eed04c0efb11393a82dd98c31b0cdcd487e739e9..4307cd4f8da096e8061b68128bf32c79ffa69daa 100644 (file)
--- a/fs/fat/fat.h
+++ b/fs/fat/fat.h
@@ -285,8 +285,11 @@ static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len)
 extern void fat_cache_inval_inode(struct inode *inode);
 extern int fat_get_cluster(struct inode *inode, int cluster,
                           int *fclus, int *dclus);
+extern int fat_get_mapped_cluster(struct inode *inode, sector_t sector,
+                                 sector_t last_block,
+                                 unsigned long *mapped_blocks, sector_t *bmap);
 extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys,
-                   unsigned long *mapped_blocks, int create);
+                   unsigned long *mapped_blocks, int create, bool from_bmap);
 
 /* fat/dir.c */
 extern const struct file_operations fat_dir_operations;

diff --git a/fs/fat/inode.c b/fs/fat/inode.c
index 0e5bc19c67b17647b672e58adcbb6cb9063e5407..a5599052116c48fcf8f5a0b0a64e9c638276a362 100644 (file)
--- a/fs/fat/inode.c
+++ b/fs/fat/inode.c
@@ -118,7 +118,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
        sector_t phys, last_block;
        int err, offset;
 
-       err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
+       err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
        if (err)
                return err;
        if (phys) {
@@ -154,7 +154,7 @@ static inline int __fat_get_block(struct inode *inode, sector_t iblock,
        *max_blocks = min(mapped_blocks, *max_blocks);
        MSDOS_I(inode)->mmu_private += *max_blocks << sb->s_blocksize_bits;
 
-       err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create);
+       err = fat_bmap(inode, iblock, &phys, &mapped_blocks, create, false);
        if (err)
                return err;
 
@@ -279,13 +279,38 @@ static ssize_t fat_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
        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;
+
+       BUG_ON(create != 0);
+
+       err = fat_bmap(inode, iblock, &bmap, &mapped_blocks, create, true);
+       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;