diff options
Diffstat (limited to 'fs/dcache.c')
| -rw-r--r-- | fs/dcache.c | 163 |
1 files changed, 96 insertions, 67 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index 03d58b2d4fa3..60046ae23d51 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1436,7 +1436,7 @@ int d_set_mounted(struct dentry *dentry) { struct dentry *p; int ret = -ENOENT; - write_seqlock(&rename_lock); + read_seqlock_excl(&rename_lock); for (p = dentry->d_parent; !IS_ROOT(p); p = p->d_parent) { /* Need exclusion wrt. d_invalidate() */ spin_lock(&p->d_lock); @@ -1456,7 +1456,7 @@ int d_set_mounted(struct dentry *dentry) } spin_unlock(&dentry->d_lock); out: - write_sequnlock(&rename_lock); + read_sequnlock_excl(&rename_lock); return ret; } @@ -1731,14 +1731,14 @@ static struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name) dentry->d_inode = NULL; dentry->d_parent = dentry; dentry->d_sb = sb; - dentry->d_op = NULL; + dentry->d_op = sb->__s_d_op; + dentry->d_flags = sb->s_d_flags; dentry->d_fsdata = NULL; INIT_HLIST_BL_NODE(&dentry->d_hash); INIT_LIST_HEAD(&dentry->d_lru); INIT_HLIST_HEAD(&dentry->d_children); INIT_HLIST_NODE(&dentry->d_u.d_alias); INIT_HLIST_NODE(&dentry->d_sib); - d_set_d_op(dentry, dentry->d_sb->s_d_op); if (dentry->d_op && dentry->d_op->d_init) { err = dentry->d_op->d_init(dentry); @@ -1821,8 +1821,9 @@ struct dentry *d_alloc_pseudo(struct super_block *sb, const struct qstr *name) struct dentry *dentry = __d_alloc(sb, name); if (likely(dentry)) { dentry->d_flags |= DCACHE_NORCU; - if (!sb->s_d_op) - d_set_d_op(dentry, &anon_ops); + /* d_op_flags(&anon_ops) is 0 */ + if (!dentry->d_op) + dentry->d_op = &anon_ops; } return dentry; } @@ -1837,35 +1838,50 @@ struct dentry *d_alloc_name(struct dentry *parent, const char *name) } EXPORT_SYMBOL(d_alloc_name); -void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) +#define DCACHE_OP_FLAGS \ + (DCACHE_OP_HASH | DCACHE_OP_COMPARE | DCACHE_OP_REVALIDATE | \ + DCACHE_OP_WEAK_REVALIDATE | DCACHE_OP_DELETE | DCACHE_OP_PRUNE | \ + DCACHE_OP_REAL) + +static unsigned int d_op_flags(const struct dentry_operations *op) { + unsigned int flags = 0; + if (op) { + if (op->d_hash) + flags |= DCACHE_OP_HASH; + if (op->d_compare) + flags |= DCACHE_OP_COMPARE; + if (op->d_revalidate) + flags |= DCACHE_OP_REVALIDATE; + if (op->d_weak_revalidate) + flags |= DCACHE_OP_WEAK_REVALIDATE; + if (op->d_delete) + flags |= DCACHE_OP_DELETE; + if (op->d_prune) + flags |= DCACHE_OP_PRUNE; + if (op->d_real) + flags |= DCACHE_OP_REAL; + } + return flags; +} + +static void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) +{ + unsigned int flags = d_op_flags(op); WARN_ON_ONCE(dentry->d_op); - WARN_ON_ONCE(dentry->d_flags & (DCACHE_OP_HASH | - DCACHE_OP_COMPARE | - DCACHE_OP_REVALIDATE | - DCACHE_OP_WEAK_REVALIDATE | - DCACHE_OP_DELETE | - DCACHE_OP_REAL)); + WARN_ON_ONCE(dentry->d_flags & DCACHE_OP_FLAGS); dentry->d_op = op; - if (!op) - return; - if (op->d_hash) - dentry->d_flags |= DCACHE_OP_HASH; - if (op->d_compare) - dentry->d_flags |= DCACHE_OP_COMPARE; - if (op->d_revalidate) - dentry->d_flags |= DCACHE_OP_REVALIDATE; - if (op->d_weak_revalidate) - dentry->d_flags |= DCACHE_OP_WEAK_REVALIDATE; - if (op->d_delete) - dentry->d_flags |= DCACHE_OP_DELETE; - if (op->d_prune) - dentry->d_flags |= DCACHE_OP_PRUNE; - if (op->d_real) - dentry->d_flags |= DCACHE_OP_REAL; - -} -EXPORT_SYMBOL(d_set_d_op); + if (flags) + dentry->d_flags |= flags; +} + +void set_default_d_op(struct super_block *s, const struct dentry_operations *ops) +{ + unsigned int flags = d_op_flags(ops); + s->__s_d_op = ops; + s->s_d_flags = (s->s_d_flags & ~DCACHE_OP_FLAGS) | flags; +} +EXPORT_SYMBOL(set_default_d_op); static unsigned d_flags_for_inode(struct inode *inode) { @@ -2530,13 +2546,19 @@ struct dentry *d_alloc_parallel(struct dentry *parent, unsigned int hash = name->hash; struct hlist_bl_head *b = in_lookup_hash(parent, hash); struct hlist_bl_node *node; - struct dentry *new = d_alloc(parent, name); + struct dentry *new = __d_alloc(parent->d_sb, name); struct dentry *dentry; unsigned seq, r_seq, d_seq; if (unlikely(!new)) return ERR_PTR(-ENOMEM); + new->d_flags |= DCACHE_PAR_LOOKUP; + spin_lock(&parent->d_lock); + new->d_parent = dget_dlock(parent); + hlist_add_head(&new->d_sib, &parent->d_children); + spin_unlock(&parent->d_lock); + retry: rcu_read_lock(); seq = smp_load_acquire(&parent->d_inode->i_dir_seq); @@ -2620,8 +2642,6 @@ retry: return dentry; } rcu_read_unlock(); - /* we can't take ->d_lock here; it's OK, though. */ - new->d_flags |= DCACHE_PAR_LOOKUP; new->d_wait = wq; hlist_bl_add_head(&new->d_u.d_in_lookup_hash, b); hlist_bl_unlock(b); @@ -2667,7 +2687,8 @@ EXPORT_SYMBOL(__d_lookup_unhash_wake); /* inode->i_lock held if inode is non-NULL */ -static inline void __d_add(struct dentry *dentry, struct inode *inode) +static inline void __d_add(struct dentry *dentry, struct inode *inode, + const struct dentry_operations *ops) { wait_queue_head_t *d_wait; struct inode *dir = NULL; @@ -2678,6 +2699,8 @@ static inline void __d_add(struct dentry *dentry, struct inode *inode) n = start_dir_add(dir); d_wait = __d_lookup_unhash(dentry); } + if (unlikely(ops)) + d_set_d_op(dentry, ops); if (inode) { unsigned add_flags = d_flags_for_inode(inode); hlist_add_head(&dentry->d_u.d_alias, &inode->i_dentry); @@ -2709,7 +2732,7 @@ void d_add(struct dentry *entry, struct inode *inode) security_d_instantiate(entry, inode); spin_lock(&inode->i_lock); } - __d_add(entry, inode); + __d_add(entry, inode, NULL); } EXPORT_SYMBOL(d_add); @@ -2774,10 +2797,10 @@ static void copy_name(struct dentry *dentry, struct dentry *target) * @target: new dentry * @exchange: exchange the two dentries * - * Update the dcache to reflect the move of a file name. Negative - * dcache entries should not be moved in this way. Caller must hold - * rename_lock, the i_mutex of the source and target directories, - * and the sb->s_vfs_rename_mutex if they differ. See lock_rename(). + * Update the dcache to reflect the move of a file name. Negative dcache + * entries should not be moved in this way. Caller must hold rename_lock, the + * i_rwsem of the source and target directories (exclusively), and the sb-> + * s_vfs_rename_mutex if they differ. See lock_rename(). */ static void __d_move(struct dentry *dentry, struct dentry *target, bool exchange) @@ -2923,7 +2946,7 @@ struct dentry *d_ancestor(struct dentry *p1, struct dentry *p2) * This helper attempts to cope with remotely renamed directories * * It assumes that the caller is already holding - * dentry->d_parent->d_inode->i_mutex, and rename_lock + * dentry->d_parent->d_inode->i_rwsem, and rename_lock * * Note: If ever the locking in lock_rename() changes, then please * remember to update this too... @@ -2961,30 +2984,8 @@ out_err: return ret; } -/** - * d_splice_alias - splice a disconnected dentry into the tree if one exists - * @inode: the inode which may have a disconnected dentry - * @dentry: a negative dentry which we want to point to the inode. - * - * If inode is a directory and has an IS_ROOT alias, then d_move that in - * place of the given dentry and return it, else simply d_add the inode - * to the dentry and return NULL. - * - * If a non-IS_ROOT directory is found, the filesystem is corrupt, and - * we should error out: directories can't have multiple aliases. - * - * This is needed in the lookup routine of any filesystem that is exportable - * (via knfsd) so that we can build dcache paths to directories effectively. - * - * If a dentry was found and moved, then it is returned. Otherwise NULL - * is returned. This matches the expected return value of ->lookup. - * - * Cluster filesystems may call this function with a negative, hashed dentry. - * In that case, we know that the inode will be a regular file, and also this - * will only occur during atomic_open. So we need to check for the dentry - * being already hashed only in the final case. - */ -struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) +struct dentry *d_splice_alias_ops(struct inode *inode, struct dentry *dentry, + const struct dentry_operations *ops) { if (IS_ERR(inode)) return ERR_CAST(inode); @@ -3030,9 +3031,37 @@ struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) } } out: - __d_add(dentry, inode); + __d_add(dentry, inode, ops); return NULL; } + +/** + * d_splice_alias - splice a disconnected dentry into the tree if one exists + * @inode: the inode which may have a disconnected dentry + * @dentry: a negative dentry which we want to point to the inode. + * + * If inode is a directory and has an IS_ROOT alias, then d_move that in + * place of the given dentry and return it, else simply d_add the inode + * to the dentry and return NULL. + * + * If a non-IS_ROOT directory is found, the filesystem is corrupt, and + * we should error out: directories can't have multiple aliases. + * + * This is needed in the lookup routine of any filesystem that is exportable + * (via knfsd) so that we can build dcache paths to directories effectively. + * + * If a dentry was found and moved, then it is returned. Otherwise NULL + * is returned. This matches the expected return value of ->lookup. + * + * Cluster filesystems may call this function with a negative, hashed dentry. + * In that case, we know that the inode will be a regular file, and also this + * will only occur during atomic_open. So we need to check for the dentry + * being already hashed only in the final case. + */ +struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) +{ + return d_splice_alias_ops(inode, dentry, NULL); +} EXPORT_SYMBOL(d_splice_alias); /* |