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465 lines
15 KiB
465 lines
15 KiB
/* SPDX-License-Identifier: GPL-2.0 */ |
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#ifndef _FAT_H |
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#define _FAT_H |
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#include <linux/buffer_head.h> |
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#include <linux/nls.h> |
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#include <linux/hash.h> |
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#include <linux/ratelimit.h> |
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#include <linux/msdos_fs.h> |
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/* |
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* vfat shortname flags |
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*/ |
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#define VFAT_SFN_DISPLAY_LOWER 0x0001 /* convert to lowercase for display */ |
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#define VFAT_SFN_DISPLAY_WIN95 0x0002 /* emulate win95 rule for display */ |
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#define VFAT_SFN_DISPLAY_WINNT 0x0004 /* emulate winnt rule for display */ |
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#define VFAT_SFN_CREATE_WIN95 0x0100 /* emulate win95 rule for create */ |
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#define VFAT_SFN_CREATE_WINNT 0x0200 /* emulate winnt rule for create */ |
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#define FAT_ERRORS_CONT 1 /* ignore error and continue */ |
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#define FAT_ERRORS_PANIC 2 /* panic on error */ |
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#define FAT_ERRORS_RO 3 /* remount r/o on error */ |
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#define FAT_NFS_STALE_RW 1 /* NFS RW support, can cause ESTALE */ |
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#define FAT_NFS_NOSTALE_RO 2 /* NFS RO support, no ESTALE issue */ |
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struct fat_mount_options { |
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kuid_t fs_uid; |
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kgid_t fs_gid; |
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unsigned short fs_fmask; |
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unsigned short fs_dmask; |
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unsigned short codepage; /* Codepage for shortname conversions */ |
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int time_offset; /* Offset of timestamps from UTC (in minutes) */ |
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char *iocharset; /* Charset used for filename input/display */ |
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unsigned short shortname; /* flags for shortname display/create rule */ |
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unsigned char name_check; /* r = relaxed, n = normal, s = strict */ |
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unsigned char errors; /* On error: continue, panic, remount-ro */ |
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unsigned char nfs; /* NFS support: nostale_ro, stale_rw */ |
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unsigned short allow_utime;/* permission for setting the [am]time */ |
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unsigned quiet:1, /* set = fake successful chmods and chowns */ |
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showexec:1, /* set = only set x bit for com/exe/bat */ |
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sys_immutable:1, /* set = system files are immutable */ |
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dotsOK:1, /* set = hidden and system files are named '.filename' */ |
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isvfat:1, /* 0=no vfat long filename support, 1=vfat support */ |
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utf8:1, /* Use of UTF-8 character set (Default) */ |
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unicode_xlate:1, /* create escape sequences for unhandled Unicode */ |
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numtail:1, /* Does first alias have a numeric '~1' type tail? */ |
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flush:1, /* write things quickly */ |
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nocase:1, /* Does this need case conversion? 0=need case conversion*/ |
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usefree:1, /* Use free_clusters for FAT32 */ |
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tz_set:1, /* Filesystem timestamps' offset set */ |
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rodir:1, /* allow ATTR_RO for directory */ |
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discard:1, /* Issue discard requests on deletions */ |
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dos1xfloppy:1; /* Assume default BPB for DOS 1.x floppies */ |
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}; |
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#define FAT_HASH_BITS 8 |
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#define FAT_HASH_SIZE (1UL << FAT_HASH_BITS) |
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/* |
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* MS-DOS file system in-core superblock data |
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*/ |
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struct msdos_sb_info { |
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unsigned short sec_per_clus; /* sectors/cluster */ |
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unsigned short cluster_bits; /* log2(cluster_size) */ |
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unsigned int cluster_size; /* cluster size */ |
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unsigned char fats, fat_bits; /* number of FATs, FAT bits (12,16 or 32) */ |
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unsigned short fat_start; |
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unsigned long fat_length; /* FAT start & length (sec.) */ |
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unsigned long dir_start; |
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unsigned short dir_entries; /* root dir start & entries */ |
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unsigned long data_start; /* first data sector */ |
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unsigned long max_cluster; /* maximum cluster number */ |
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unsigned long root_cluster; /* first cluster of the root directory */ |
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unsigned long fsinfo_sector; /* sector number of FAT32 fsinfo */ |
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struct mutex fat_lock; |
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struct mutex nfs_build_inode_lock; |
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struct mutex s_lock; |
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unsigned int prev_free; /* previously allocated cluster number */ |
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unsigned int free_clusters; /* -1 if undefined */ |
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unsigned int free_clus_valid; /* is free_clusters valid? */ |
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struct fat_mount_options options; |
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struct nls_table *nls_disk; /* Codepage used on disk */ |
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struct nls_table *nls_io; /* Charset used for input and display */ |
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const void *dir_ops; /* Opaque; default directory operations */ |
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int dir_per_block; /* dir entries per block */ |
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int dir_per_block_bits; /* log2(dir_per_block) */ |
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unsigned int vol_id; /*volume ID*/ |
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int fatent_shift; |
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const struct fatent_operations *fatent_ops; |
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struct inode *fat_inode; |
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struct inode *fsinfo_inode; |
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struct ratelimit_state ratelimit; |
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spinlock_t inode_hash_lock; |
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struct hlist_head inode_hashtable[FAT_HASH_SIZE]; |
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spinlock_t dir_hash_lock; |
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struct hlist_head dir_hashtable[FAT_HASH_SIZE]; |
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unsigned int dirty; /* fs state before mount */ |
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struct rcu_head rcu; |
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}; |
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#define FAT_CACHE_VALID 0 /* special case for valid cache */ |
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/* |
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* MS-DOS file system inode data in memory |
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*/ |
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struct msdos_inode_info { |
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spinlock_t cache_lru_lock; |
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struct list_head cache_lru; |
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int nr_caches; |
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/* for avoiding the race between fat_free() and fat_get_cluster() */ |
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unsigned int cache_valid_id; |
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/* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */ |
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loff_t mmu_private; /* physically allocated size */ |
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int i_start; /* first cluster or 0 */ |
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int i_logstart; /* logical first cluster */ |
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int i_attrs; /* unused attribute bits */ |
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loff_t i_pos; /* on-disk position of directory entry or 0 */ |
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struct hlist_node i_fat_hash; /* hash by i_location */ |
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struct hlist_node i_dir_hash; /* hash by i_logstart */ |
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struct rw_semaphore truncate_lock; /* protect bmap against truncate */ |
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struct inode vfs_inode; |
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}; |
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struct fat_slot_info { |
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loff_t i_pos; /* on-disk position of directory entry */ |
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loff_t slot_off; /* offset for slot or de start */ |
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int nr_slots; /* number of slots + 1(de) in filename */ |
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struct msdos_dir_entry *de; |
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struct buffer_head *bh; |
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}; |
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static inline struct msdos_sb_info *MSDOS_SB(struct super_block *sb) |
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{ |
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return sb->s_fs_info; |
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} |
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/* |
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* Functions that determine the variant of the FAT file system (i.e., |
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* whether this is FAT12, FAT16 or FAT32. |
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*/ |
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static inline bool is_fat12(const struct msdos_sb_info *sbi) |
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{ |
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return sbi->fat_bits == 12; |
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} |
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static inline bool is_fat16(const struct msdos_sb_info *sbi) |
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{ |
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return sbi->fat_bits == 16; |
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} |
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static inline bool is_fat32(const struct msdos_sb_info *sbi) |
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{ |
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return sbi->fat_bits == 32; |
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} |
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/* Maximum number of clusters */ |
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static inline u32 max_fat(struct super_block *sb) |
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{ |
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struct msdos_sb_info *sbi = MSDOS_SB(sb); |
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return is_fat32(sbi) ? MAX_FAT32 : |
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is_fat16(sbi) ? MAX_FAT16 : MAX_FAT12; |
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} |
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static inline struct msdos_inode_info *MSDOS_I(struct inode *inode) |
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{ |
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return container_of(inode, struct msdos_inode_info, vfs_inode); |
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} |
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/* |
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* If ->i_mode can't hold S_IWUGO (i.e. ATTR_RO), we use ->i_attrs to |
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* save ATTR_RO instead of ->i_mode. |
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* |
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* If it's directory and !sbi->options.rodir, ATTR_RO isn't read-only |
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* bit, it's just used as flag for app. |
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*/ |
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static inline int fat_mode_can_hold_ro(struct inode *inode) |
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{ |
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struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); |
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umode_t mask; |
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if (S_ISDIR(inode->i_mode)) { |
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if (!sbi->options.rodir) |
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return 0; |
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mask = ~sbi->options.fs_dmask; |
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} else |
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mask = ~sbi->options.fs_fmask; |
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if (!(mask & S_IWUGO)) |
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return 0; |
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return 1; |
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} |
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/* Convert attribute bits and a mask to the UNIX mode. */ |
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static inline umode_t fat_make_mode(struct msdos_sb_info *sbi, |
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u8 attrs, umode_t mode) |
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{ |
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if (attrs & ATTR_RO && !((attrs & ATTR_DIR) && !sbi->options.rodir)) |
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mode &= ~S_IWUGO; |
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if (attrs & ATTR_DIR) |
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return (mode & ~sbi->options.fs_dmask) | S_IFDIR; |
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else |
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return (mode & ~sbi->options.fs_fmask) | S_IFREG; |
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} |
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/* Return the FAT attribute byte for this inode */ |
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static inline u8 fat_make_attrs(struct inode *inode) |
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{ |
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u8 attrs = MSDOS_I(inode)->i_attrs; |
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if (S_ISDIR(inode->i_mode)) |
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attrs |= ATTR_DIR; |
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if (fat_mode_can_hold_ro(inode) && !(inode->i_mode & S_IWUGO)) |
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attrs |= ATTR_RO; |
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return attrs; |
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} |
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static inline void fat_save_attrs(struct inode *inode, u8 attrs) |
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{ |
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if (fat_mode_can_hold_ro(inode)) |
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MSDOS_I(inode)->i_attrs = attrs & ATTR_UNUSED; |
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else |
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MSDOS_I(inode)->i_attrs = attrs & (ATTR_UNUSED | ATTR_RO); |
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} |
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static inline unsigned char fat_checksum(const __u8 *name) |
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{ |
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unsigned char s = name[0]; |
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s = (s<<7) + (s>>1) + name[1]; s = (s<<7) + (s>>1) + name[2]; |
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s = (s<<7) + (s>>1) + name[3]; s = (s<<7) + (s>>1) + name[4]; |
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s = (s<<7) + (s>>1) + name[5]; s = (s<<7) + (s>>1) + name[6]; |
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s = (s<<7) + (s>>1) + name[7]; s = (s<<7) + (s>>1) + name[8]; |
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s = (s<<7) + (s>>1) + name[9]; s = (s<<7) + (s>>1) + name[10]; |
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return s; |
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} |
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static inline sector_t fat_clus_to_blknr(struct msdos_sb_info *sbi, int clus) |
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{ |
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return ((sector_t)clus - FAT_START_ENT) * sbi->sec_per_clus |
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+ sbi->data_start; |
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} |
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static inline void fat_get_blknr_offset(struct msdos_sb_info *sbi, |
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loff_t i_pos, sector_t *blknr, int *offset) |
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{ |
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*blknr = i_pos >> sbi->dir_per_block_bits; |
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*offset = i_pos & (sbi->dir_per_block - 1); |
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} |
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static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi, |
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struct inode *inode) |
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{ |
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loff_t i_pos; |
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#if BITS_PER_LONG == 32 |
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spin_lock(&sbi->inode_hash_lock); |
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#endif |
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i_pos = MSDOS_I(inode)->i_pos; |
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#if BITS_PER_LONG == 32 |
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spin_unlock(&sbi->inode_hash_lock); |
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#endif |
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return i_pos; |
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} |
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static inline void fat16_towchar(wchar_t *dst, const __u8 *src, size_t len) |
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{ |
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#ifdef __BIG_ENDIAN |
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while (len--) { |
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*dst++ = src[0] | (src[1] << 8); |
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src += 2; |
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} |
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#else |
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memcpy(dst, src, len * 2); |
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#endif |
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} |
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static inline int fat_get_start(const struct msdos_sb_info *sbi, |
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const struct msdos_dir_entry *de) |
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{ |
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int cluster = le16_to_cpu(de->start); |
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if (is_fat32(sbi)) |
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cluster |= (le16_to_cpu(de->starthi) << 16); |
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return cluster; |
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} |
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static inline void fat_set_start(struct msdos_dir_entry *de, int cluster) |
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{ |
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de->start = cpu_to_le16(cluster); |
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de->starthi = cpu_to_le16(cluster >> 16); |
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} |
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static inline void fatwchar_to16(__u8 *dst, const wchar_t *src, size_t len) |
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{ |
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#ifdef __BIG_ENDIAN |
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while (len--) { |
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dst[0] = *src & 0x00FF; |
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dst[1] = (*src & 0xFF00) >> 8; |
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dst += 2; |
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src++; |
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} |
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#else |
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memcpy(dst, src, len * 2); |
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#endif |
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} |
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/* fat/cache.c */ |
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extern void fat_cache_inval_inode(struct inode *inode); |
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extern int fat_get_cluster(struct inode *inode, int cluster, |
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int *fclus, int *dclus); |
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extern int fat_get_mapped_cluster(struct inode *inode, sector_t sector, |
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sector_t last_block, |
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unsigned long *mapped_blocks, sector_t *bmap); |
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extern int fat_bmap(struct inode *inode, sector_t sector, sector_t *phys, |
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unsigned long *mapped_blocks, int create, bool from_bmap); |
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/* fat/dir.c */ |
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extern const struct file_operations fat_dir_operations; |
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extern int fat_search_long(struct inode *inode, const unsigned char *name, |
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int name_len, struct fat_slot_info *sinfo); |
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extern int fat_dir_empty(struct inode *dir); |
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extern int fat_subdirs(struct inode *dir); |
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extern int fat_scan(struct inode *dir, const unsigned char *name, |
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struct fat_slot_info *sinfo); |
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extern int fat_scan_logstart(struct inode *dir, int i_logstart, |
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struct fat_slot_info *sinfo); |
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extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, |
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struct msdos_dir_entry **de); |
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extern int fat_alloc_new_dir(struct inode *dir, struct timespec64 *ts); |
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extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, |
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struct fat_slot_info *sinfo); |
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extern int fat_remove_entries(struct inode *dir, struct fat_slot_info *sinfo); |
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/* fat/fatent.c */ |
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struct fat_entry { |
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int entry; |
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union { |
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u8 *ent12_p[2]; |
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__le16 *ent16_p; |
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__le32 *ent32_p; |
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} u; |
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int nr_bhs; |
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struct buffer_head *bhs[2]; |
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struct inode *fat_inode; |
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}; |
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static inline void fatent_init(struct fat_entry *fatent) |
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{ |
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fatent->nr_bhs = 0; |
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fatent->entry = 0; |
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fatent->u.ent32_p = NULL; |
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fatent->bhs[0] = fatent->bhs[1] = NULL; |
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fatent->fat_inode = NULL; |
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} |
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static inline void fatent_set_entry(struct fat_entry *fatent, int entry) |
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{ |
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fatent->entry = entry; |
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fatent->u.ent32_p = NULL; |
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} |
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static inline void fatent_brelse(struct fat_entry *fatent) |
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{ |
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int i; |
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fatent->u.ent32_p = NULL; |
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for (i = 0; i < fatent->nr_bhs; i++) |
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brelse(fatent->bhs[i]); |
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fatent->nr_bhs = 0; |
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fatent->bhs[0] = fatent->bhs[1] = NULL; |
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fatent->fat_inode = NULL; |
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} |
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static inline bool fat_valid_entry(struct msdos_sb_info *sbi, int entry) |
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{ |
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return FAT_START_ENT <= entry && entry < sbi->max_cluster; |
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} |
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extern void fat_ent_access_init(struct super_block *sb); |
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extern int fat_ent_read(struct inode *inode, struct fat_entry *fatent, |
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int entry); |
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extern int fat_ent_write(struct inode *inode, struct fat_entry *fatent, |
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int new, int wait); |
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extern int fat_alloc_clusters(struct inode *inode, int *cluster, |
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int nr_cluster); |
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extern int fat_free_clusters(struct inode *inode, int cluster); |
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extern int fat_count_free_clusters(struct super_block *sb); |
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extern int fat_trim_fs(struct inode *inode, struct fstrim_range *range); |
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/* fat/file.c */ |
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extern long fat_generic_ioctl(struct file *filp, unsigned int cmd, |
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unsigned long arg); |
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extern const struct file_operations fat_file_operations; |
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extern const struct inode_operations fat_file_inode_operations; |
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extern int fat_setattr(struct user_namespace *mnt_userns, struct dentry *dentry, |
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struct iattr *attr); |
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extern void fat_truncate_blocks(struct inode *inode, loff_t offset); |
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extern int fat_getattr(struct user_namespace *mnt_userns, |
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const struct path *path, struct kstat *stat, |
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u32 request_mask, unsigned int flags); |
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extern int fat_file_fsync(struct file *file, loff_t start, loff_t end, |
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int datasync); |
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/* fat/inode.c */ |
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extern int fat_block_truncate_page(struct inode *inode, loff_t from); |
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extern void fat_attach(struct inode *inode, loff_t i_pos); |
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extern void fat_detach(struct inode *inode); |
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extern struct inode *fat_iget(struct super_block *sb, loff_t i_pos); |
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extern struct inode *fat_build_inode(struct super_block *sb, |
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struct msdos_dir_entry *de, loff_t i_pos); |
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extern int fat_sync_inode(struct inode *inode); |
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extern int fat_fill_super(struct super_block *sb, void *data, int silent, |
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int isvfat, void (*setup)(struct super_block *)); |
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extern int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de); |
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extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, |
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struct inode *i2); |
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static inline unsigned long fat_dir_hash(int logstart) |
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{ |
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return hash_32(logstart, FAT_HASH_BITS); |
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} |
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extern int fat_add_cluster(struct inode *inode); |
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/* fat/misc.c */ |
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extern __printf(3, 4) __cold |
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void __fat_fs_error(struct super_block *sb, int report, const char *fmt, ...); |
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#define fat_fs_error(sb, fmt, args...) \ |
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__fat_fs_error(sb, 1, fmt , ## args) |
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#define fat_fs_error_ratelimit(sb, fmt, args...) \ |
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__fat_fs_error(sb, __ratelimit(&MSDOS_SB(sb)->ratelimit), fmt , ## args) |
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__printf(3, 4) __cold |
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void fat_msg(struct super_block *sb, const char *level, const char *fmt, ...); |
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#define fat_msg_ratelimit(sb, level, fmt, args...) \ |
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do { \ |
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if (__ratelimit(&MSDOS_SB(sb)->ratelimit)) \ |
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fat_msg(sb, level, fmt, ## args); \ |
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} while (0) |
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extern int fat_clusters_flush(struct super_block *sb); |
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extern int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster); |
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extern void fat_time_fat2unix(struct msdos_sb_info *sbi, struct timespec64 *ts, |
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__le16 __time, __le16 __date, u8 time_cs); |
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extern void fat_time_unix2fat(struct msdos_sb_info *sbi, struct timespec64 *ts, |
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__le16 *time, __le16 *date, u8 *time_cs); |
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extern int fat_truncate_time(struct inode *inode, struct timespec64 *now, |
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int flags); |
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extern int fat_update_time(struct inode *inode, struct timespec64 *now, |
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int flags); |
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extern int fat_sync_bhs(struct buffer_head **bhs, int nr_bhs); |
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int fat_cache_init(void); |
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void fat_cache_destroy(void); |
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/* fat/nfs.c */ |
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extern const struct export_operations fat_export_ops; |
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extern const struct export_operations fat_export_ops_nostale; |
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/* helper for printk */ |
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typedef unsigned long long llu; |
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#endif /* !_FAT_H */
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