478 lines
16 KiB
C
478 lines
16 KiB
C
/* 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 timespec64 i_crtime; /* File creation (birth) time */
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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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#define FAT_PRINTK_PREFIX "%sFAT-fs (%s): "
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#define fat_msg(sb, level, fmt, args...) \
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do { \
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printk_index_subsys_emit(FAT_PRINTK_PREFIX, level, fmt, ##args);\
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_fat_msg(sb, level, fmt, ##args); \
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} while (0)
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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 struct timespec64 fat_truncate_atime(const struct msdos_sb_info *sbi,
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const struct timespec64 *ts);
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extern struct timespec64 fat_truncate_mtime(const struct msdos_sb_info *sbi,
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|
const struct timespec64 *ts);
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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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|
|
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int fat_cache_init(void);
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void fat_cache_destroy(void);
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|
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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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|
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/* helper for printk */
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typedef unsigned long long llu;
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|
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#endif /* !_FAT_H */
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