diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 69b1497b0029e778210a8003496e9ba25261a6ba..2dce2334737d3bce48fa77c0f83adadc5bd21d7d 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -52,6 +52,7 @@ struct autofs_info { int flags; + struct list_head active; struct list_head expiring; struct autofs_sb_info *sbi; @@ -113,6 +114,7 @@ struct autofs_sb_info { spinlock_t fs_lock; struct autofs_wait_queue *queues; /* Wait queue pointer */ spinlock_t lookup_lock; + struct list_head active_list; struct list_head expiring_list; }; diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c index 94bfc154d7a2a5ac9fcc69279a692d885cb6ee51..e3e70994ab463d62914f7417a11b213e4276f8b7 100644 --- a/fs/autofs4/inode.c +++ b/fs/autofs4/inode.c @@ -24,8 +24,10 @@ static void ino_lnkfree(struct autofs_info *ino) { - kfree(ino->u.symlink); - ino->u.symlink = NULL; + if (ino->u.symlink) { + kfree(ino->u.symlink); + ino->u.symlink = NULL; + } } struct autofs_info *autofs4_init_ino(struct autofs_info *ino, @@ -41,16 +43,18 @@ struct autofs_info *autofs4_init_ino(struct autofs_info *ino, if (ino == NULL) return NULL; - ino->flags = 0; - ino->mode = mode; - ino->inode = NULL; - ino->dentry = NULL; - ino->size = 0; - - INIT_LIST_HEAD(&ino->expiring); + if (!reinit) { + ino->flags = 0; + ino->inode = NULL; + ino->dentry = NULL; + ino->size = 0; + INIT_LIST_HEAD(&ino->active); + INIT_LIST_HEAD(&ino->expiring); + atomic_set(&ino->count, 0); + } + ino->mode = mode; ino->last_used = jiffies; - atomic_set(&ino->count, 0); ino->sbi = sbi; @@ -339,6 +343,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) spin_lock_init(&sbi->fs_lock); sbi->queues = NULL; spin_lock_init(&sbi->lookup_lock); + INIT_LIST_HEAD(&sbi->active_list); INIT_LIST_HEAD(&sbi->expiring_list); s->s_blocksize = 1024; s->s_blocksize_bits = 10; diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 53dabe8d5b8bd85015e56a71f744190b5301a600..dbb70d5a48827f0516db8a1455bea8b4a29b6cbb 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -473,6 +473,8 @@ void autofs4_dentry_release(struct dentry *de) if (sbi) { spin_lock(&sbi->lookup_lock); + if (!list_empty(&inf->active)) + list_del(&inf->active); if (!list_empty(&inf->expiring)) list_del(&inf->expiring); spin_unlock(&sbi->lookup_lock); @@ -497,6 +499,58 @@ static struct dentry_operations autofs4_dentry_operations = { .d_release = autofs4_dentry_release, }; +static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name) +{ + unsigned int len = name->len; + unsigned int hash = name->hash; + const unsigned char *str = name->name; + struct list_head *p, *head; + + spin_lock(&dcache_lock); + spin_lock(&sbi->lookup_lock); + head = &sbi->active_list; + list_for_each(p, head) { + struct autofs_info *ino; + struct dentry *dentry; + struct qstr *qstr; + + ino = list_entry(p, struct autofs_info, active); + dentry = ino->dentry; + + spin_lock(&dentry->d_lock); + + /* Already gone? */ + if (atomic_read(&dentry->d_count) == 0) + goto next; + + qstr = &dentry->d_name; + + if (dentry->d_name.hash != hash) + goto next; + if (dentry->d_parent != parent) + goto next; + + if (qstr->len != len) + goto next; + if (memcmp(qstr->name, str, len)) + goto next; + + if (d_unhashed(dentry)) { + dget(dentry); + spin_unlock(&dentry->d_lock); + spin_unlock(&sbi->lookup_lock); + spin_unlock(&dcache_lock); + return dentry; + } +next: + spin_unlock(&dentry->d_lock); + } + spin_unlock(&sbi->lookup_lock); + spin_unlock(&dcache_lock); + + return NULL; +} + static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name) { unsigned int len = name->len; @@ -553,7 +607,8 @@ static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct autofs_sb_info *sbi; - struct dentry *expiring; + struct autofs_info *ino; + struct dentry *expiring, *unhashed; int oz_mode; DPRINTK("name = %.*s", @@ -571,12 +626,12 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s expiring = autofs4_lookup_expiring(sbi, dentry->d_parent, &dentry->d_name); if (expiring) { - struct autofs_info *ino = autofs4_dentry_ino(expiring); /* * If we are racing with expire the request might not * be quite complete but the directory has been removed * so it must have been successful, so just wait for it. */ + ino = autofs4_dentry_ino(expiring); while (ino && (ino->flags & AUTOFS_INF_EXPIRING)) { DPRINTK("wait for incomplete expire %p name=%.*s", expiring, expiring->d_name.len, @@ -591,21 +646,41 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s dput(expiring); } - /* - * Mark the dentry incomplete but don't hash it. We do this - * to serialize our inode creation operations (symlink and - * mkdir) which prevents deadlock during the callback to - * the daemon. Subsequent user space lookups for the same - * dentry are placed on the wait queue while the daemon - * itself is allowed passage unresticted so the create - * operation itself can then hash the dentry. Finally, - * we check for the hashed dentry and return the newly - * hashed dentry. - */ - dentry->d_op = &autofs4_root_dentry_operations; + unhashed = autofs4_lookup_active(sbi, dentry->d_parent, &dentry->d_name); + if (unhashed) + dentry = unhashed; + else { + /* + * Mark the dentry incomplete but don't hash it. We do this + * to serialize our inode creation operations (symlink and + * mkdir) which prevents deadlock during the callback to + * the daemon. Subsequent user space lookups for the same + * dentry are placed on the wait queue while the daemon + * itself is allowed passage unresticted so the create + * operation itself can then hash the dentry. Finally, + * we check for the hashed dentry and return the newly + * hashed dentry. + */ + dentry->d_op = &autofs4_root_dentry_operations; + + /* + * And we need to ensure that the same dentry is used for + * all following lookup calls until it is hashed so that + * the dentry flags are persistent throughout the request. + */ + ino = autofs4_init_ino(NULL, sbi, 0555); + if (!ino) + return ERR_PTR(-ENOMEM); + + dentry->d_fsdata = ino; + ino->dentry = dentry; + + spin_lock(&sbi->lookup_lock); + list_add(&ino->active, &sbi->active_list); + spin_unlock(&sbi->lookup_lock); - dentry->d_fsdata = NULL; - d_instantiate(dentry, NULL); + d_instantiate(dentry, NULL); + } if (!oz_mode) { spin_lock(&dentry->d_lock); @@ -630,12 +705,16 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s if (sigismember (sigset, SIGKILL) || sigismember (sigset, SIGQUIT) || sigismember (sigset, SIGINT)) { + if (unhashed) + dput(unhashed); return ERR_PTR(-ERESTARTNOINTR); } } - spin_lock(&dentry->d_lock); - dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; - spin_unlock(&dentry->d_lock); + if (!oz_mode) { + spin_lock(&dentry->d_lock); + dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; + spin_unlock(&dentry->d_lock); + } } /* @@ -659,9 +738,15 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s else dentry = ERR_PTR(-ENOENT); + if (unhashed) + dput(unhashed); + return dentry; } + if (unhashed) + return unhashed; + return NULL; } @@ -682,20 +767,30 @@ static int autofs4_dir_symlink(struct inode *dir, return -EACCES; ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); - if (ino == NULL) - return -ENOSPC; + if (!ino) + return -ENOMEM; - ino->size = strlen(symname); - ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL); + spin_lock(&sbi->lookup_lock); + if (!list_empty(&ino->active)) + list_del_init(&ino->active); + spin_unlock(&sbi->lookup_lock); - if (cp == NULL) { - kfree(ino); - return -ENOSPC; + cp = kmalloc(ino->size + 1, GFP_KERNEL); + if (!cp) { + if (!dentry->d_fsdata) + kfree(ino); + return -ENOMEM; } strcpy(cp, symname); inode = autofs4_get_inode(dir->i_sb, ino); + if (!inode) { + kfree(cp); + if (!dentry->d_fsdata) + kfree(ino); + return -ENOMEM; + } d_add(dentry, inode); if (dir == dir->i_sb->s_root->d_inode) @@ -711,6 +806,8 @@ static int autofs4_dir_symlink(struct inode *dir, atomic_inc(&p_ino->count); ino->inode = inode; + ino->size = strlen(symname); + ino->u.symlink = cp; dir->i_mtime = CURRENT_TIME; return 0; @@ -755,7 +852,8 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) spin_lock(&dcache_lock); spin_lock(&sbi->lookup_lock); - list_add(&ino->expiring, &sbi->expiring_list); + if (list_empty(&ino->expiring)) + list_add(&ino->expiring, &sbi->expiring_list); spin_unlock(&sbi->lookup_lock); spin_lock(&dentry->d_lock); __d_drop(dentry); @@ -783,7 +881,8 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) return -ENOTEMPTY; } spin_lock(&sbi->lookup_lock); - list_add(&ino->expiring, &sbi->expiring_list); + if (list_empty(&ino->expiring)) + list_add(&ino->expiring, &sbi->expiring_list); spin_unlock(&sbi->lookup_lock); spin_lock(&dentry->d_lock); __d_drop(dentry); @@ -819,10 +918,20 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) dentry, dentry->d_name.len, dentry->d_name.name); ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); - if (ino == NULL) - return -ENOSPC; + if (!ino) + return -ENOMEM; + + spin_lock(&sbi->lookup_lock); + if (!list_empty(&ino->active)) + list_del_init(&ino->active); + spin_unlock(&sbi->lookup_lock); inode = autofs4_get_inode(dir->i_sb, ino); + if (!inode) { + if (!dentry->d_fsdata) + kfree(ino); + return -ENOMEM; + } d_add(dentry, inode); if (dir == dir->i_sb->s_root->d_inode)