diff options
Diffstat (limited to 'fs/fat')
| -rw-r--r-- | fs/fat/dir.c | 20 | ||||
| -rw-r--r-- | fs/fat/fat.h | 27 | ||||
| -rw-r--r-- | fs/fat/inode.c | 71 | ||||
| -rw-r--r-- | fs/fat/namei_msdos.c | 5 | ||||
| -rw-r--r-- | fs/fat/namei_vfat.c | 5 | ||||
| -rw-r--r-- | fs/fat/nfs.c | 150 |
6 files changed, 141 insertions, 137 deletions
diff --git a/fs/fat/dir.c b/fs/fat/dir.c index d70d8f3..55e088c 100644 --- a/fs/fat/dir.c +++ b/fs/fat/dir.c @@ -872,21 +872,23 @@ static int fat_get_short_entry(struct inode *dir, loff_t *pos, } /* - * The ".." entry can not provide the "struct fat_slot_info" informations - * for inode. So, this function provide the some informations only. + * The ".." entry can not provide the "struct fat_slot_info" information + * for inode, nor a usable i_pos. So, this function provides some information + * only. + * + * Since this function walks through the on-disk inodes within a directory, + * callers are responsible for taking any locks necessary to prevent the + * directory from changing. */ int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, - struct msdos_dir_entry **de, loff_t *i_pos) + struct msdos_dir_entry **de) { - loff_t offset; + loff_t offset = 0; - offset = 0; - *bh = NULL; + *de = NULL; while (fat_get_short_entry(dir, &offset, bh, de) >= 0) { - if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) { - *i_pos = fat_make_i_pos(dir->i_sb, *bh, *de); + if (!strncmp((*de)->name, MSDOS_DOTDOT, MSDOS_NAME)) return 0; - } } return -ENOENT; } diff --git a/fs/fat/fat.h b/fs/fat/fat.h index fb95939..ec54c3a 100644 --- a/fs/fat/fat.h +++ b/fs/fat/fat.h @@ -5,6 +5,7 @@ #include <linux/string.h> #include <linux/nls.h> #include <linux/fs.h> +#include <linux/hash.h> #include <linux/mutex.h> #include <linux/ratelimit.h> #include <linux/msdos_fs.h> @@ -46,7 +47,8 @@ struct fat_mount_options { usefree:1, /* Use free_clusters for FAT32 */ tz_utc:1, /* Filesystem timestamps are in UTC */ rodir:1, /* allow ATTR_RO for directory */ - discard:1; /* Issue discard requests on deletions */ + discard:1, /* Issue discard requests on deletions */ + nfs:1; /* Do extra work needed for NFS export */ }; #define FAT_HASH_BITS 8 @@ -88,6 +90,9 @@ struct msdos_sb_info { spinlock_t inode_hash_lock; struct hlist_head inode_hashtable[FAT_HASH_SIZE]; + + spinlock_t dir_hash_lock; + struct hlist_head dir_hashtable[FAT_HASH_SIZE]; }; #define FAT_CACHE_VALID 0 /* special case for valid cache */ @@ -110,6 +115,7 @@ struct msdos_inode_info { int i_attrs; /* unused attribute bits */ loff_t i_pos; /* on-disk position of directory entry or 0 */ struct hlist_node i_fat_hash; /* hash by i_location */ + struct hlist_node i_dir_hash; /* hash by i_logstart */ struct rw_semaphore truncate_lock; /* protect bmap against truncate */ struct inode vfs_inode; }; @@ -262,7 +268,7 @@ extern int fat_subdirs(struct inode *dir); extern int fat_scan(struct inode *dir, const unsigned char *name, struct fat_slot_info *sinfo); extern int fat_get_dotdot_entry(struct inode *dir, struct buffer_head **bh, - struct msdos_dir_entry **de, loff_t *i_pos); + struct msdos_dir_entry **de); extern int fat_alloc_new_dir(struct inode *dir, struct timespec *ts); extern int fat_add_entries(struct inode *dir, void *slots, int nr_slots, struct fat_slot_info *sinfo); @@ -341,18 +347,9 @@ extern int fat_fill_super(struct super_block *sb, void *data, int silent, extern int fat_flush_inodes(struct super_block *sb, struct inode *i1, struct inode *i2); -static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi, - struct inode *inode) +static inline unsigned long fat_dir_hash(int logstart) { - loff_t i_pos; -#if BITS_PER_LONG == 32 - spin_lock(&sbi->inode_hash_lock); -#endif - i_pos = MSDOS_I(inode)->i_pos; -#if BITS_PER_LONG == 32 - spin_unlock(&sbi->inode_hash_lock); -#endif - return i_pos; + return hash_32(logstart, FAT_HASH_BITS); } /* fat/misc.c */ @@ -382,10 +379,10 @@ void fat_cache_destroy(void); /* fat/nfs.c */ struct fid; -extern int fat_encode_fh(struct inode *inode, __u32 *fh, int *lenp, - struct inode *parent); extern struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type); +extern struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type); extern struct dentry *fat_get_parent(struct dentry *child_dir); /* helper for printk */ diff --git a/fs/fat/inode.c b/fs/fat/inode.c index 169f6eb..5741b11 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -281,15 +281,42 @@ static inline unsigned long fat_hash(loff_t i_pos) return hash_32(i_pos, FAT_HASH_BITS); } +static void dir_hash_init(struct super_block *sb) +{ + struct msdos_sb_info *sbi = MSDOS_SB(sb); + int i; + + spin_lock_init(&sbi->dir_hash_lock); + for (i = 0; i < FAT_HASH_SIZE; i++) + INIT_HLIST_HEAD(&sbi->dir_hashtable[i]); +} + void fat_attach(struct inode *inode, loff_t i_pos) { struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); - struct hlist_head *head = sbi->inode_hashtable + fat_hash(i_pos); - spin_lock(&sbi->inode_hash_lock); - MSDOS_I(inode)->i_pos = i_pos; - hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); - spin_unlock(&sbi->inode_hash_lock); + if (inode->i_ino != MSDOS_ROOT_INO) { + struct hlist_head *head = sbi->inode_hashtable + + fat_hash(i_pos); + + spin_lock(&sbi->inode_hash_lock); + MSDOS_I(inode)->i_pos = i_pos; + hlist_add_head(&MSDOS_I(inode)->i_fat_hash, head); + spin_unlock(&sbi->inode_hash_lock); + } + + /* If NFS support is enabled, cache the mapping of start cluster + * to directory inode. This is used during reconnection of + * dentries to the filesystem root. + */ + if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { + struct hlist_head *d_head = sbi->dir_hashtable; + d_head += fat_dir_hash(MSDOS_I(inode)->i_logstart); + + spin_lock(&sbi->dir_hash_lock); + hlist_add_head(&MSDOS_I(inode)->i_dir_hash, d_head); + spin_unlock(&sbi->dir_hash_lock); + } } EXPORT_SYMBOL_GPL(fat_attach); @@ -300,6 +327,12 @@ void fat_detach(struct inode *inode) MSDOS_I(inode)->i_pos = 0; hlist_del_init(&MSDOS_I(inode)->i_fat_hash); spin_unlock(&sbi->inode_hash_lock); + + if (S_ISDIR(inode->i_mode) && sbi->options.nfs) { + spin_lock(&sbi->dir_hash_lock); + hlist_del_init(&MSDOS_I(inode)->i_dir_hash); + spin_unlock(&sbi->dir_hash_lock); + } } EXPORT_SYMBOL_GPL(fat_detach); @@ -504,6 +537,7 @@ static void init_once(void *foo) ei->cache_valid_id = FAT_CACHE_VALID + 1; INIT_LIST_HEAD(&ei->cache_lru); INIT_HLIST_NODE(&ei->i_fat_hash); + INIT_HLIST_NODE(&ei->i_dir_hash); inode_init_once(&ei->vfs_inode); } @@ -562,6 +596,20 @@ static int fat_statfs(struct dentry *dentry, struct kstatfs *buf) return 0; } +static inline loff_t fat_i_pos_read(struct msdos_sb_info *sbi, + struct inode *inode) +{ + loff_t i_pos; +#if BITS_PER_LONG == 32 + spin_lock(&sbi->inode_hash_lock); +#endif + i_pos = MSDOS_I(inode)->i_pos; +#if BITS_PER_LONG == 32 + spin_unlock(&sbi->inode_hash_lock); +#endif + return i_pos; +} + static int __fat_write_inode(struct inode *inode, int wait) { struct super_block *sb = inode->i_sb; @@ -655,8 +703,8 @@ static const struct super_operations fat_sops = { }; static const struct export_operations fat_export_ops = { - .encode_fh = fat_encode_fh, .fh_to_dentry = fat_fh_to_dentry, + .fh_to_parent = fat_fh_to_parent, .get_parent = fat_get_parent, }; @@ -706,6 +754,8 @@ static int fat_show_options(struct seq_file *m, struct dentry *root) seq_puts(m, ",usefree"); if (opts->quiet) seq_puts(m, ",quiet"); + if (opts->nfs) + seq_puts(m, ",nfs"); if (opts->showexec) seq_puts(m, ",showexec"); if (opts->sys_immutable) @@ -750,7 +800,7 @@ enum { Opt_shortname_winnt, Opt_shortname_mixed, Opt_utf8_no, Opt_utf8_yes, Opt_uni_xl_no, Opt_uni_xl_yes, Opt_nonumtail_no, Opt_nonumtail_yes, Opt_obsolete, Opt_flush, Opt_tz_utc, Opt_rodir, Opt_err_cont, - Opt_err_panic, Opt_err_ro, Opt_discard, Opt_err, + Opt_err_panic, Opt_err_ro, Opt_discard, Opt_nfs, Opt_err, }; static const match_table_t fat_tokens = { @@ -779,6 +829,7 @@ static const match_table_t fat_tokens = { {Opt_err_panic, "errors=panic"}, {Opt_err_ro, "errors=remount-ro"}, {Opt_discard, "discard"}, + {Opt_nfs, "nfs"}, {Opt_obsolete, "conv=binary"}, {Opt_obsolete, "conv=text"}, {Opt_obsolete, "conv=auto"}, @@ -859,6 +910,7 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, opts->numtail = 1; opts->usefree = opts->nocase = 0; opts->tz_utc = 0; + opts->nfs = 0; opts->errors = FAT_ERRORS_RO; *debug = 0; @@ -1023,6 +1075,9 @@ static int parse_options(struct super_block *sb, char *options, int is_vfat, case Opt_discard: opts->discard = 1; break; + case Opt_nfs: + opts->nfs = 1; + break; /* obsolete mount options */ case Opt_obsolete: @@ -1313,6 +1368,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, /* set up enough so that it can read an inode */ fat_hash_init(sb); + dir_hash_init(sb); fat_ent_access_init(sb); /* @@ -1367,6 +1423,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, } error = -ENOMEM; insert_inode_hash(root_inode); + fat_attach(root_inode, 0); sb->s_root = d_make_root(root_inode); if (!sb->s_root) { fat_msg(sb, KERN_ERR, "get root inode failed"); diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c index b0e12bf..c27c630 100644 --- a/fs/fat/namei_msdos.c +++ b/fs/fat/namei_msdos.c @@ -440,7 +440,7 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name, struct inode *old_inode, *new_inode; struct fat_slot_info old_sinfo, sinfo; struct timespec ts; - loff_t dotdot_i_pos, new_i_pos; + loff_t new_i_pos; int err, old_attrs, is_dir, update_dotdot, corrupt = 0; old_sinfo.bh = sinfo.bh = dotdot_bh = NULL; @@ -456,8 +456,7 @@ static int do_msdos_rename(struct inode *old_dir, unsigned char *old_name, is_dir = S_ISDIR(old_inode->i_mode); update_dotdot = (is_dir && old_dir != new_dir); if (update_dotdot) { - if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de, - &dotdot_i_pos) < 0) { + if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) { err = -EIO; goto out; } diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c index 6a6d8c0..e535dd7 100644 --- a/fs/fat/namei_vfat.c +++ b/fs/fat/namei_vfat.c @@ -914,7 +914,7 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *old_inode, *new_inode; struct fat_slot_info old_sinfo, sinfo; struct timespec ts; - loff_t dotdot_i_pos, new_i_pos; + loff_t new_i_pos; int err, is_dir, update_dotdot, corrupt = 0; struct super_block *sb = old_dir->i_sb; @@ -929,8 +929,7 @@ static int vfat_rename(struct inode *old_dir, struct dentry *old_dentry, is_dir = S_ISDIR(old_inode->i_mode); update_dotdot = (is_dir && old_dir != new_dir); if (update_dotdot) { - if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de, - &dotdot_i_pos) < 0) { + if (fat_get_dotdot_entry(old_inode, &dotdot_bh, &dotdot_de)) { err = -EIO; goto out; } diff --git a/fs/fat/nfs.c b/fs/fat/nfs.c index 21609a1..ef4b5fa 100644 --- a/fs/fat/nfs.c +++ b/fs/fat/nfs.c @@ -14,47 +14,46 @@ #include <linux/exportfs.h> #include "fat.h" -/* - * a FAT file handle with fhtype 3 is - * 0/ i_ino - for fast, reliable lookup if still in the cache - * 1/ i_generation - to see if i_ino is still valid - * bit 0 == 0 iff directory - * 2/ i_pos(8-39) - if ino has changed, but still in cache - * 3/ i_pos(4-7)|i_logstart - to semi-verify inode found at i_pos - * 4/ i_pos(0-3)|parent->i_logstart - maybe used to hunt for the file on disc - * - * Hack for NFSv2: Maximum FAT entry number is 28bits and maximum - * i_pos is 40bits (blocknr(32) + dir offset(8)), so two 4bits - * of i_logstart is used to store the directory entry offset. +/** + * Look up a directory inode given its starting cluster. */ - -int -fat_encode_fh(struct inode *inode, __u32 *fh, int *lenp, struct inode *parent) +static struct inode *fat_dget(struct super_block *sb, int i_logstart) { - int len = *lenp; - struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb); - loff_t i_pos; + struct msdos_sb_info *sbi = MSDOS_SB(sb); + struct hlist_head *head; + struct hlist_node *_p; + struct msdos_inode_info *i; + struct inode *inode = NULL; - if (len < 5) { - *lenp = 5; - return 255; /* no room */ + head = sbi->dir_hashtable + fat_dir_hash(i_logstart); + spin_lock(&sbi->dir_hash_lock); + hlist_for_each_entry(i, _p, head, i_dir_hash) { + BUG_ON(i->vfs_inode.i_sb != sb); + if (i->i_logstart != i_logstart) + continue; + inode = igrab(&i->vfs_inode); + if (inode) + break; } - - i_pos = fat_i_pos_read(sbi, inode); - *lenp = 5; - fh[0] = inode->i_ino; - fh[1] = inode->i_generation; - fh[2] = i_pos >> 8; - fh[3] = ((i_pos & 0xf0) << 24) | MSDOS_I(inode)->i_logstart; - fh[4] = (i_pos & 0x0f) << 28; - if (parent) - fh[4] |= MSDOS_I(parent)->i_logstart; - return 3; + spin_unlock(&sbi->dir_hash_lock); + return inode; } -static int fat_is_valid_fh(int fh_len, int fh_type) +static struct inode *fat_nfs_get_inode(struct super_block *sb, + u64 ino, u32 generation) { - return ((fh_len >= 5) && (fh_type == 3)); + struct inode *inode; + + if ((ino < MSDOS_ROOT_INO) || (ino == MSDOS_FSINFO_INO)) + return NULL; + + inode = ilookup(sb, ino); + if (inode && generation && (inode->i_generation != generation)) { + iput(inode); + inode = NULL; + } + + return inode; } /** @@ -64,57 +63,19 @@ static int fat_is_valid_fh(int fh_len, int fh_type) struct dentry *fat_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len, int fh_type) { - struct inode *inode = NULL; - u32 *fh = fid->raw; - loff_t i_pos; - unsigned long i_ino; - __u32 i_generation; - int i_logstart; - - if (!fat_is_valid_fh(fh_len, fh_type)) - return NULL; - - i_ino = fh[0]; - i_generation = fh[1]; - i_logstart = fh[3] & 0x0fffffff; - - /* Try i_ino lookup first - fastest and most reliable */ - inode = ilookup(sb, i_ino); - if (inode && (inode->i_generation != i_generation)) { - iput(inode); - inode = NULL; - } - if (!inode) { - i_pos = (loff_t)fh[2] << 8; - i_pos |= ((fh[3] >> 24) & 0xf0) | (fh[4] >> 28); - - /* try 2 - see if i_pos is in F-d-c - * require i_logstart to be the same - * Will fail if you truncate and then re-write - */ - - inode = fat_iget(sb, i_pos); - if (inode && MSDOS_I(inode)->i_logstart != i_logstart) { - iput(inode); - inode = NULL; - } - } + return generic_fh_to_dentry(sb, fid, fh_len, fh_type, + fat_nfs_get_inode); +} - /* - * For now, do nothing if the inode is not found. - * - * What we could do is: - * - * - follow the file starting at fh[4], and record the ".." entry, - * and the name of the fh[2] entry. - * - then follow the ".." file finding the next step up. - * - * This way we build a path to the root of the tree. If this works, we - * lookup the path and so get this inode into the cache. Finally try - * the fat_iget lookup again. If that fails, then we are totally out - * of luck. But all that is for another day - */ - return d_obtain_alias(inode); +/* + * Find the parent for a file specified by NFS handle. + * This requires that the handle contain the i_ino of the parent. + */ +struct dentry *fat_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + return generic_fh_to_parent(sb, fid, fh_len, fh_type, + fat_nfs_get_inode); } /* @@ -128,24 +89,13 @@ struct dentry *fat_get_parent(struct dentry *child_dir) struct super_block *sb = child_dir->d_sb; struct buffer_head *bh = NULL; struct msdos_dir_entry *de; - loff_t i_pos; - struct dentry *parent; - struct inode *inode; - int err; + struct inode *parent_inode = NULL; - lock_super(sb); - - err = fat_get_dotdot_entry(child_dir->d_inode, &bh, &de, &i_pos); - if (err) { - parent = ERR_PTR(err); - goto out; + if (!fat_get_dotdot_entry(child_dir->d_inode, &bh, &de)) { + int parent_logstart = fat_get_start(MSDOS_SB(sb), de); + parent_inode = fat_dget(sb, parent_logstart); } - inode = fat_build_inode(sb, de, i_pos); - - parent = d_obtain_alias(inode); -out: brelse(bh); - unlock_super(sb); - return parent; + return d_obtain_alias(parent_inode); } |
