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Commit 16fab201 authored by Namjae Jeon's avatar Namjae Jeon Committed by Linus Torvalds
Browse files

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: default avatarNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: default avatarAmit Sahrawat <a.sahrawat@samsung.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7e0f236b

fs/fat/cache.c

+54 −25
Original line number Diff line number Diff line
@@ -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);

}

fs/fat/dir.c

+1 −1
Original line number Diff line number Diff line
@@ -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 */

fs/fat/fat.h

+4 −1
Original line number Diff line number Diff line
@@ -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;

fs/fat/inode.c

+28 −3
Original line number Diff line number Diff line
@@ -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;