From 306790f75ac2fe021a900395255e468807002c42 Mon Sep 17 00:00:00 2001 From: Carmeli Tamir Date: Thu, 3 Jan 2019 15:28:00 -0800 Subject: [PATCH] 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: Carmeli Tamir Acked-by: OGAWA Hirofumi Reviewed-by: Sergey Senozhatsky Cc: Johannes Thumshirn Cc: Bart Van Assche Cc: Martin K. Petersen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fat/cache.c | 2 +- fs/fat/dir.c | 4 ++-- fs/fat/fat.h | 25 ++++++++++++++++++++++--- fs/fat/fatent.c | 16 +++++++--------- fs/fat/inode.c | 12 ++++++------ fs/fat/misc.c | 2 +- 6 files changed, 39 insertions(+), 22 deletions(-) diff --git a/fs/fat/cache.c b/fs/fat/cache.c index 78d501c1fb65..738e427e2d21 100644 --- a/fs/fat/cache.c +++ b/fs/fat/cache.c @@ -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; diff --git a/fs/fat/dir.c b/fs/fat/dir.c index c8366cb8eccd..20acaea8a7e6 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -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)", diff --git a/fs/fat/fat.h b/fs/fat/fat.h index 979bb11832f6..922a0c6ba46c 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -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; } diff --git a/fs/fat/fatent.c b/fs/fat/fatent.c index f58c0cacc531..495edeafd60a 100644 --- a/fs/fat/fatent.c +++ b/fs/fat/fatent.c @@ -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) { diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 8d0de1aac4eb..79bb0e73a65f 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -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; diff --git a/fs/fat/misc.c b/fs/fat/misc.c index fce0a76f3f1e..4fc950bb6433 100644 --- a/fs/fat/misc.c +++ b/fs/fat/misc.c @@ -64,7 +64,7 @@ int fat_clusters_flush(struct super_block *sb) struct buffer_head *bh; struct fat_boot_fsinfo *fsinfo; - if (sbi->fat_bits != 32) + if (!is_fat32(sbi)) return 0; bh = sb_bread(sb, sbi->fsinfo_sector);