Commit 306790f7 authored by Carmeli Tamir's avatar Carmeli Tamir Committed by Linus Torvalds
Browse files

fat: new inline functions to determine the FAT variant (32, 16 or 12) 

This patch introduces 3 new inline functions - is_fat12, is_fat16 and
is_fat32, and replaces every occurrence in the code in which the FS
variant (whether this is FAT12, FAT16 or FAT32) was previously checked
using msdos_sb_info->fat_bits.

Link: http://lkml.kernel.org/r/1544990640-11604-4-git-send-email-carmeli.tamir@gmail.com


Signed-off-by: default avatarCarmeli Tamir <carmeli.tamir@gmail.com>
Acked-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reviewed-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d19dc016

fs/fat/cache.c

+1 −1
Original line number Diff line number Diff line
@@ -363,7 +363,7 @@ int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, 


	*phys = 0;

	*mapped_blocks = 0;

	if ((sbi->fat_bits != 32) && (inode->i_ino == MSDOS_ROOT_INO)) {

	if (!is_fat32(sbi) && (inode->i_ino == MSDOS_ROOT_INO)) {

		if (sector < (sbi->dir_entries >> sbi->dir_per_block_bits)) {

			*phys = sector + sbi->dir_start;

			*mapped_blocks = 1;

fs/fat/dir.c

+2 −2
Original line number Diff line number Diff line
@@ -57,7 +57,7 @@ static inline void fat_dir_readahead(struct inode *dir, sector_t iblock, 
	if ((iblock & (sbi->sec_per_clus - 1)) || sbi->sec_per_clus == 1)

		return;

	/* root dir of FAT12/FAT16 */

	if ((sbi->fat_bits != 32) && (dir->i_ino == MSDOS_ROOT_INO))

	if (!is_fat32(sbi) && (dir->i_ino == MSDOS_ROOT_INO))

		return;



	bh = sb_find_get_block(sb, phys);
@@ -1313,7 +1313,7 @@ int fat_add_entries(struct inode *dir, void *slots, int nr_slots, 
		}

	}

	if (dir->i_ino == MSDOS_ROOT_INO) {

		if (sbi->fat_bits != 32)

		if (!is_fat32(sbi))

			goto error;

	} else if (MSDOS_I(dir)->i_start == 0) {

		fat_msg(sb, KERN_ERR, "Corrupted directory (i_pos %lld)",

fs/fat/fat.h

+22 −3
Original line number Diff line number Diff line
@@ -142,13 +142,32 @@ static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb) 
	return sb->s_fs_info;

}



/*

 * Functions that determine the variant of the FAT file system (i.e.,

 * whether this is FAT12, FAT16 or FAT32.

 */

static inline bool is_fat12(const struct msdos_sb_info *sbi)

{

	return sbi->fat_bits == 12;

}



static inline bool is_fat16(const struct msdos_sb_info *sbi)

{

	return sbi->fat_bits == 16;

}



static inline bool is_fat32(const struct msdos_sb_info *sbi)

{

	return sbi->fat_bits == 32;

}



/* Maximum number of clusters */

static inline u32 max_fat(struct super_block *sb)

{

	struct msdos_sb_info *sbi = MSDOS_SB(sb);



	return sbi->fat_bits == 32 ? MAX_FAT32 :

		sbi->fat_bits == 16 ? MAX_FAT16 : MAX_FAT12;

	return is_fat32(sbi) ? MAX_FAT32 :

		is_fat16(sbi) ? MAX_FAT16 : MAX_FAT12;

}



static inline struct msdos_inode_info *MSDOS_I(struct inode *inode)
@@ -266,7 +285,7 @@ static inline int fat_get_start(const struct msdos_sb_info *sbi, 
				const struct msdos_dir_entry *de)

{

	int cluster = le16_to_cpu(de->start);

	if (sbi->fat_bits == 32)

	if (is_fat32(sbi))

		cluster |= (le16_to_cpu(de->starthi) << 16);

	return cluster;

}

fs/fat/fatent.c

+7 −9
Original line number Diff line number Diff line
@@ -290,19 +290,17 @@ void fat_ent_access_init(struct super_block *sb) 


	mutex_init(&sbi->fat_lock);



	switch (sbi->fat_bits) {

	case 32:

	if (is_fat32(sbi)) {

		sbi->fatent_shift = 2;

		sbi->fatent_ops = &fat32_ops;

		break;

	case 16:

	} else if (is_fat16(sbi)) {

		sbi->fatent_shift = 1;

		sbi->fatent_ops = &fat16_ops;

		break;

	case 12:

	} else if (is_fat12(sbi)) {

		sbi->fatent_shift = -1;

		sbi->fatent_ops = &fat12_ops;

		break;

	} else {

		fat_fs_error(sb, "invalid FAT variant, %u bits", sbi->fat_bits);

	}

}
@@ -310,7 +308,7 @@ static void mark_fsinfo_dirty(struct super_block *sb) 
{

	struct msdos_sb_info *sbi = MSDOS_SB(sb);



	if (sb_rdonly(sb) || sbi->fat_bits != 32)

	if (sb_rdonly(sb) || !is_fat32(sbi))

		return;



	__mark_inode_dirty(sbi->fsinfo_inode, I_DIRTY_SYNC);
@@ -327,7 +325,7 @@ static inline int fat_ent_update_ptr(struct super_block *sb, 
	/* Is this fatent's blocks including this entry? */

	if (!fatent->nr_bhs || bhs[0]->b_blocknr != blocknr)

		return 0;

	if (sbi->fat_bits == 12) {

	if (is_fat12(sbi)) {

		if ((offset + 1) < sb->s_blocksize) {

			/* This entry is on bhs[0]. */

			if (fatent->nr_bhs == 2) {

fs/fat/inode.c

+6 −6
Original line number Diff line number Diff line
@@ -686,7 +686,7 @@ static void fat_set_state(struct super_block *sb, 


	b = (struct fat_boot_sector *) bh->b_data;



	if (sbi->fat_bits == 32) {

	if (is_fat32(sbi)) {

		if (set)

			b->fat32.state |= FAT_STATE_DIRTY;

		else
@@ -1396,7 +1396,7 @@ static int fat_read_root(struct inode *inode) 
	inode->i_mode = fat_make_mode(sbi, ATTR_DIR, S_IRWXUGO);

	inode->i_op = sbi->dir_ops;

	inode->i_fop = &fat_dir_operations;

	if (sbi->fat_bits == 32) {

	if (is_fat32(sbi)) {

		MSDOS_I(inode)->i_start = sbi->root_cluster;

		error = fat_calc_dir_size(inode);

		if (error < 0)
@@ -1423,7 +1423,7 @@ static unsigned long calc_fat_clusters(struct super_block *sb) 
	struct msdos_sb_info *sbi = MSDOS_SB(sb);



	/* Divide first to avoid overflow */

	if (sbi->fat_bits != 12) {

	if (!is_fat12(sbi)) {

		unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits;

		return ent_per_sec * sbi->fat_length;

	}
@@ -1743,7 +1743,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 
	}



	/* interpret volume ID as a little endian 32 bit integer */

	if (sbi->fat_bits == 32)

	if (is_fat32(sbi))

		sbi->vol_id = bpb.fat32_vol_id;

	else /* fat 16 or 12 */

		sbi->vol_id = bpb.fat16_vol_id;
@@ -1769,11 +1769,11 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, 


	total_clusters = (total_sectors - sbi->data_start) / sbi->sec_per_clus;



	if (sbi->fat_bits != 32)

	if (!is_fat32(sbi))

		sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12;



	/* some OSes set FAT_STATE_DIRTY and clean it on unmount. */

	if (sbi->fat_bits == 32)

	if (is_fat32(sbi))

		sbi->dirty = bpb.fat32_state & FAT_STATE_DIRTY;

	else /* fat 16 or 12 */

		sbi->dirty = bpb.fat16_state & FAT_STATE_DIRTY;

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