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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>
This commit is contained in:
Namjae Jeon 2016-01-20 14:59:46 -08:00 committed by Linus Torvalds
parent 7e0f236b5b
commit 16fab20150
4 changed files with 87 additions and 30 deletions
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79
fs/fat/cache.c
View File

@ -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);
}

2
fs/fat/dir.c
View File

@ -91,7 +91,7 @@ static int fat__get_entry(struct inode *dir, loff_t *pos,
*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 */

5
fs/fat/fat.h
View File

@ -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;

31
fs/fat/inode.c
View File

@ -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;