autofs4: always use lookup for lookup
We need to be able to cope with the directory mutex being held during ->d_revalidate() in some cases, but not all cases, and not necessarily by us. Because we need to release the mutex when we call back to the daemon to do perform a mount we must be sure that it is us who holds the mutex so we must redirect mount requests to ->lookup() if the mutex is held. Signed-off-by: Ian Kent <raven@themaw.net> Cc: Sage Weil <sage@newdream.net> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Andreas Dilger <adilger@sun.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Yehuda Saheh <yehuda@newdream.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ian Kent
Linus Torvalds
parent
cb4b492ac7
commit
213614d583
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@ -60,6 +60,11 @@ do { \
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current->pid, __func__, ##args); \
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} while (0)
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struct rehash_entry {
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struct task_struct *task;
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struct list_head list;
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};
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/* Unified info structure. This is pointed to by both the dentry and
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inode structures. Each file in the filesystem has an instance of this
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structure. It holds a reference to the dentry, so dentries are never
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@ -76,6 +81,7 @@ struct autofs_info {
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struct list_head active;
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int active_count;
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struct list_head rehash_list;
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struct list_head expiring;
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@ -98,6 +104,7 @@ struct autofs_info {
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#define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
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#define AUTOFS_INF_MOUNTPOINT (1<<1) /* mountpoint status for direct expire */
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#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
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#define AUTOFS_INF_REHASH (1<<3) /* dentry in transit to ->lookup() */
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struct autofs_wait_queue {
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wait_queue_head_t queue;
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@ -279,6 +279,7 @@ struct dentry *autofs4_expire_direct(struct super_block *sb,
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root->d_mounted--;
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}
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ino->flags |= AUTOFS_INF_EXPIRING;
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autofs4_add_expiring(root);
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init_completion(&ino->expire_complete);
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spin_unlock(&sbi->fs_lock);
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return root;
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@ -406,6 +407,7 @@ found:
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expired, (int)expired->d_name.len, expired->d_name.name);
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ino = autofs4_dentry_ino(expired);
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ino->flags |= AUTOFS_INF_EXPIRING;
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autofs4_add_expiring(expired);
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init_completion(&ino->expire_complete);
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spin_unlock(&sbi->fs_lock);
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spin_lock(&dcache_lock);
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@ -433,7 +435,7 @@ int autofs4_expire_wait(struct dentry *dentry)
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DPRINTK("expire done status=%d", status);
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if (d_unhashed(dentry))
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if (d_unhashed(dentry) && IS_DEADDIR(dentry->d_inode))
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return -EAGAIN;
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return status;
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@ -473,6 +475,7 @@ int autofs4_expire_run(struct super_block *sb,
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spin_lock(&sbi->fs_lock);
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ino = autofs4_dentry_ino(dentry);
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ino->flags &= ~AUTOFS_INF_EXPIRING;
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autofs4_del_expiring(dentry);
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complete_all(&ino->expire_complete);
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spin_unlock(&sbi->fs_lock);
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@ -503,6 +506,7 @@ int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
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ino->flags &= ~AUTOFS_INF_MOUNTPOINT;
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}
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ino->flags &= ~AUTOFS_INF_EXPIRING;
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autofs4_del_expiring(dentry);
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complete_all(&ino->expire_complete);
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spin_unlock(&sbi->fs_lock);
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dput(dentry);
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@ -49,6 +49,7 @@ struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
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ino->dentry = NULL;
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ino->size = 0;
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INIT_LIST_HEAD(&ino->active);
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INIT_LIST_HEAD(&ino->rehash_list);
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ino->active_count = 0;
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INIT_LIST_HEAD(&ino->expiring);
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atomic_set(&ino->count, 0);
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@ -104,6 +104,99 @@ static void autofs4_del_active(struct dentry *dentry)
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return;
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}
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static void autofs4_add_rehash_entry(struct autofs_info *ino,
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struct rehash_entry *entry)
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{
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entry->task = current;
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INIT_LIST_HEAD(&entry->list);
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list_add(&entry->list, &ino->rehash_list);
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return;
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}
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static void autofs4_remove_rehash_entry(struct autofs_info *ino)
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{
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struct list_head *head = &ino->rehash_list;
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struct rehash_entry *entry;
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list_for_each_entry(entry, head, list) {
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if (entry->task == current) {
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list_del(&entry->list);
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kfree(entry);
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break;
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}
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}
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return;
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}
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static void autofs4_remove_rehash_entrys(struct autofs_info *ino)
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{
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struct autofs_sb_info *sbi = ino->sbi;
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struct rehash_entry *entry, *next;
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struct list_head *head;
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spin_lock(&sbi->fs_lock);
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spin_lock(&sbi->lookup_lock);
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if (!(ino->flags & AUTOFS_INF_REHASH)) {
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spin_unlock(&sbi->lookup_lock);
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spin_unlock(&sbi->fs_lock);
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return;
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}
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ino->flags &= ~AUTOFS_INF_REHASH;
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head = &ino->rehash_list;
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list_for_each_entry_safe(entry, next, head, list) {
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list_del(&entry->list);
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kfree(entry);
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}
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spin_unlock(&sbi->lookup_lock);
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spin_unlock(&sbi->fs_lock);
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dput(ino->dentry);
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return;
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}
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static void autofs4_revalidate_drop(struct dentry *dentry,
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struct rehash_entry *entry)
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{
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struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
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struct autofs_info *ino = autofs4_dentry_ino(dentry);
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/*
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* Add to the active list so we can pick this up in
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* ->lookup(). Also add an entry to a rehash list so
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* we know when there are no dentrys in flight so we
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* know when we can rehash the dentry.
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*/
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spin_lock(&sbi->lookup_lock);
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if (list_empty(&ino->active))
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list_add(&ino->active, &sbi->active_list);
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autofs4_add_rehash_entry(ino, entry);
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spin_unlock(&sbi->lookup_lock);
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if (!(ino->flags & AUTOFS_INF_REHASH)) {
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ino->flags |= AUTOFS_INF_REHASH;
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dget(dentry);
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spin_lock(&dentry->d_lock);
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__d_drop(dentry);
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spin_unlock(&dentry->d_lock);
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}
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return;
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}
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static void autofs4_revalidate_rehash(struct dentry *dentry)
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{
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struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
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struct autofs_info *ino = autofs4_dentry_ino(dentry);
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if (ino->flags & AUTOFS_INF_REHASH) {
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spin_lock(&sbi->lookup_lock);
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autofs4_remove_rehash_entry(ino);
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if (list_empty(&ino->rehash_list)) {
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spin_unlock(&sbi->lookup_lock);
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ino->flags &= ~AUTOFS_INF_REHASH;
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d_rehash(dentry);
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dput(ino->dentry);
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} else
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spin_unlock(&sbi->lookup_lock);
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}
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return;
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}
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static unsigned int autofs4_need_mount(unsigned int flags)
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{
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unsigned int res = 0;
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@ -143,7 +236,7 @@ out:
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return dcache_dir_open(inode, file);
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}
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static int try_to_fill_dentry(struct dentry *dentry, int flags)
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static int try_to_fill_dentry(struct dentry *dentry)
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{
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struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
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struct autofs_info *ino = autofs4_dentry_ino(dentry);
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@ -156,55 +249,17 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
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* Wait for a pending mount, triggering one if there
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* isn't one already
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*/
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if (dentry->d_inode == NULL) {
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DPRINTK("waiting for mount name=%.*s",
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dentry->d_name.len, dentry->d_name.name);
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DPRINTK("waiting for mount name=%.*s",
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dentry->d_name.len, dentry->d_name.name);
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status = autofs4_wait(sbi, dentry, NFY_MOUNT);
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status = autofs4_wait(sbi, dentry, NFY_MOUNT);
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DPRINTK("mount done status=%d", status);
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DPRINTK("mount done status=%d", status);
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/* Turn this into a real negative dentry? */
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if (status == -ENOENT) {
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spin_lock(&sbi->fs_lock);
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ino->flags &= ~AUTOFS_INF_PENDING;
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spin_unlock(&sbi->fs_lock);
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return status;
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} else if (status) {
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/* Return a negative dentry, but leave it "pending" */
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return status;
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}
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/* Trigger mount for path component or follow link */
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} else if (ino->flags & AUTOFS_INF_PENDING ||
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autofs4_need_mount(flags) ||
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current->link_count) {
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DPRINTK("waiting for mount name=%.*s",
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dentry->d_name.len, dentry->d_name.name);
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/* Update expiry counter */
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ino->last_used = jiffies;
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spin_lock(&sbi->fs_lock);
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ino->flags |= AUTOFS_INF_PENDING;
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spin_unlock(&sbi->fs_lock);
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status = autofs4_wait(sbi, dentry, NFY_MOUNT);
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DPRINTK("mount done status=%d", status);
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if (status) {
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spin_lock(&sbi->fs_lock);
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ino->flags &= ~AUTOFS_INF_PENDING;
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spin_unlock(&sbi->fs_lock);
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return status;
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}
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}
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/* Initialize expiry counter after successful mount */
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if (ino)
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ino->last_used = jiffies;
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spin_lock(&sbi->fs_lock);
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ino->flags &= ~AUTOFS_INF_PENDING;
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spin_unlock(&sbi->fs_lock);
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return 0;
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return status;
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}
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/* For autofs direct mounts the follow link triggers the mount */
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@ -258,10 +313,16 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
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*/
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if (ino->flags & AUTOFS_INF_PENDING ||
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(!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
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ino->flags |= AUTOFS_INF_PENDING;
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spin_unlock(&dcache_lock);
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spin_unlock(&sbi->fs_lock);
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status = try_to_fill_dentry(dentry, 0);
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status = try_to_fill_dentry(dentry);
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spin_lock(&sbi->fs_lock);
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ino->flags &= ~AUTOFS_INF_PENDING;
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spin_unlock(&sbi->fs_lock);
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if (status)
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goto out_error;
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@ -300,18 +361,47 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
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{
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struct inode *dir = dentry->d_parent->d_inode;
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struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
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int oz_mode = autofs4_oz_mode(sbi);
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struct autofs_info *ino = autofs4_dentry_ino(dentry);
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struct rehash_entry *entry;
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int flags = nd ? nd->flags : 0;
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int status = 1;
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unsigned int mutex_aquired;
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DPRINTK("name = %.*s oz_mode = %d",
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dentry->d_name.len, dentry->d_name.name, oz_mode);
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/* Daemon never causes a mount to trigger */
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if (autofs4_oz_mode(sbi))
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return 1;
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entry = kmalloc(sizeof(struct rehash_entry), GFP_KERNEL);
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if (!entry)
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return -ENOMEM;
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mutex_aquired = mutex_trylock(&dir->i_mutex);
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/* Pending dentry */
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spin_lock(&sbi->fs_lock);
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spin_lock(&dcache_lock);
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/* Pending dentry */
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if (autofs4_ispending(dentry)) {
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/* The daemon never causes a mount to trigger */
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spin_unlock(&sbi->fs_lock);
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int status;
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if (oz_mode)
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return 1;
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/*
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* We can only unhash and send this to ->lookup() if
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* the directory mutex is held over d_revalidate() and
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* ->lookup(). This prevents the VFS from incorrectly
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* seeing the dentry as non-existent.
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*/
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ino->flags |= AUTOFS_INF_PENDING;
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if (!mutex_aquired) {
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autofs4_revalidate_drop(dentry, entry);
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spin_unlock(&dcache_lock);
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spin_unlock(&sbi->fs_lock);
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return 0;
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}
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spin_unlock(&dcache_lock);
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spin_unlock(&sbi->fs_lock);
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mutex_unlock(&dir->i_mutex);
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kfree(entry);
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/*
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* If the directory has gone away due to an expire
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@ -325,45 +415,82 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
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* A zero status is success otherwise we have a
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* negative error code.
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*/
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status = try_to_fill_dentry(dentry, flags);
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status = try_to_fill_dentry(dentry);
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spin_lock(&sbi->fs_lock);
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ino->flags &= ~AUTOFS_INF_PENDING;
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spin_unlock(&sbi->fs_lock);
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if (status == 0)
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return 1;
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return status;
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}
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spin_unlock(&sbi->fs_lock);
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/* Negative dentry.. invalidate if "old" */
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if (dentry->d_inode == NULL)
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return 0;
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/* Check for a non-mountpoint directory with no contents */
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spin_lock(&dcache_lock);
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if (S_ISDIR(dentry->d_inode->i_mode) &&
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!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
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DPRINTK("dentry=%p %.*s, emptydir",
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dentry, dentry->d_name.len, dentry->d_name.name);
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spin_unlock(&dcache_lock);
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/* The daemon never causes a mount to trigger */
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if (oz_mode)
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return 1;
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if (autofs4_need_mount(flags) || current->link_count) {
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int status;
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/*
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* A zero status is success otherwise we have a
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* negative error code.
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*/
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status = try_to_fill_dentry(dentry, flags);
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if (status == 0)
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return 1;
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/*
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* We can only unhash and send this to ->lookup() if
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* the directory mutex is held over d_revalidate() and
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* ->lookup(). This prevents the VFS from incorrectly
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* seeing the dentry as non-existent.
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*/
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ino->flags |= AUTOFS_INF_PENDING;
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if (!mutex_aquired) {
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autofs4_revalidate_drop(dentry, entry);
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spin_unlock(&dcache_lock);
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spin_unlock(&sbi->fs_lock);
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return 0;
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}
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spin_unlock(&dcache_lock);
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spin_unlock(&sbi->fs_lock);
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mutex_unlock(&dir->i_mutex);
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kfree(entry);
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return status;
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/*
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* A zero status is success otherwise we have a
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* negative error code.
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*/
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status = try_to_fill_dentry(dentry);
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spin_lock(&sbi->fs_lock);
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ino->flags &= ~AUTOFS_INF_PENDING;
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spin_unlock(&sbi->fs_lock);
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if (status == 0)
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return 1;
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return status;
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}
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}
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spin_unlock(&dcache_lock);
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spin_unlock(&sbi->fs_lock);
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if (mutex_aquired)
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mutex_unlock(&dir->i_mutex);
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kfree(entry);
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return 1;
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}
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static void autofs4_free_rehash_entrys(struct autofs_info *inf)
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{
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struct list_head *head = &inf->rehash_list;
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struct rehash_entry *entry, *next;
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list_for_each_entry_safe(entry, next, head, list) {
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list_del(&entry->list);
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kfree(entry);
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}
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}
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void autofs4_dentry_release(struct dentry *de)
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{
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struct autofs_info *inf;
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@ -382,6 +509,8 @@ void autofs4_dentry_release(struct dentry *de)
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list_del(&inf->active);
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if (!list_empty(&inf->expiring))
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list_del(&inf->expiring);
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if (!list_empty(&inf->rehash_list))
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autofs4_free_rehash_entrys(inf);
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spin_unlock(&sbi->lookup_lock);
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}
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@ -414,6 +543,7 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
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const unsigned char *str = name->name;
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struct list_head *p, *head;
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||||
|
||||
restart:
|
||||
spin_lock(&dcache_lock);
|
||||
spin_lock(&sbi->lookup_lock);
|
||||
head = &sbi->active_list;
|
||||
|
|
@ -431,6 +561,19 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
|
|||
if (atomic_read(&active->d_count) == 0)
|
||||
goto next;
|
||||
|
||||
if (active->d_inode && IS_DEADDIR(active->d_inode)) {
|
||||
if (!list_empty(&ino->rehash_list)) {
|
||||
dget(active);
|
||||
spin_unlock(&active->d_lock);
|
||||
spin_unlock(&sbi->lookup_lock);
|
||||
spin_unlock(&dcache_lock);
|
||||
autofs4_remove_rehash_entrys(ino);
|
||||
dput(active);
|
||||
goto restart;
|
||||
}
|
||||
goto next;
|
||||
}
|
||||
|
||||
qstr = &active->d_name;
|
||||
|
||||
if (active->d_name.hash != hash)
|
||||
|
|
@ -443,13 +586,11 @@ static struct dentry *autofs4_lookup_active(struct dentry *dentry)
|
|||
if (memcmp(qstr->name, str, len))
|
||||
goto next;
|
||||
|
||||
if (d_unhashed(active)) {
|
||||
dget(active);
|
||||
spin_unlock(&active->d_lock);
|
||||
spin_unlock(&sbi->lookup_lock);
|
||||
spin_unlock(&dcache_lock);
|
||||
return active;
|
||||
}
|
||||
dget(active);
|
||||
spin_unlock(&active->d_lock);
|
||||
spin_unlock(&sbi->lookup_lock);
|
||||
spin_unlock(&dcache_lock);
|
||||
return active;
|
||||
next:
|
||||
spin_unlock(&active->d_lock);
|
||||
}
|
||||
|
|
@ -498,13 +639,11 @@ static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
|
|||
if (memcmp(qstr->name, str, len))
|
||||
goto next;
|
||||
|
||||
if (d_unhashed(expiring)) {
|
||||
dget(expiring);
|
||||
spin_unlock(&expiring->d_lock);
|
||||
spin_unlock(&sbi->lookup_lock);
|
||||
spin_unlock(&dcache_lock);
|
||||
return expiring;
|
||||
}
|
||||
dget(expiring);
|
||||
spin_unlock(&expiring->d_lock);
|
||||
spin_unlock(&sbi->lookup_lock);
|
||||
spin_unlock(&dcache_lock);
|
||||
return expiring;
|
||||
next:
|
||||
spin_unlock(&expiring->d_lock);
|
||||
}
|
||||
|
|
@ -514,6 +653,48 @@ next:
|
|||
return NULL;
|
||||
}
|
||||
|
||||
static struct autofs_info *init_new_dentry(struct autofs_sb_info *sbi,
|
||||
struct dentry *dentry, int oz_mode)
|
||||
{
|
||||
struct autofs_info *ino;
|
||||
|
||||
/*
|
||||
* 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;
|
||||
|
||||
/*
|
||||
* Only set the mount pending flag for new dentrys not created
|
||||
* by the daemon.
|
||||
*/
|
||||
if (!oz_mode)
|
||||
ino->flags |= AUTOFS_INF_PENDING;
|
||||
|
||||
d_instantiate(dentry, NULL);
|
||||
|
||||
return ino;
|
||||
}
|
||||
|
||||
/* Lookups in the root directory */
|
||||
static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
|
||||
{
|
||||
|
|
@ -521,6 +702,7 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
|
|||
struct autofs_info *ino;
|
||||
struct dentry *expiring, *active;
|
||||
int oz_mode;
|
||||
int status = 0;
|
||||
|
||||
DPRINTK("name = %.*s",
|
||||
dentry->d_name.len, dentry->d_name.name);
|
||||
|
|
@ -535,44 +717,26 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
|
|||
DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
|
||||
current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
|
||||
|
||||
spin_lock(&sbi->fs_lock);
|
||||
active = autofs4_lookup_active(dentry);
|
||||
if (active) {
|
||||
dentry = active;
|
||||
ino = autofs4_dentry_ino(dentry);
|
||||
/* If this came from revalidate, rehash it */
|
||||
autofs4_revalidate_rehash(dentry);
|
||||
spin_unlock(&sbi->fs_lock);
|
||||
} 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;
|
||||
|
||||
autofs4_add_active(dentry);
|
||||
|
||||
d_instantiate(dentry, NULL);
|
||||
spin_unlock(&sbi->fs_lock);
|
||||
ino = init_new_dentry(sbi, dentry, oz_mode);
|
||||
if (IS_ERR(ino))
|
||||
return (struct dentry *) ino;
|
||||
}
|
||||
|
||||
autofs4_add_active(dentry);
|
||||
|
||||
if (!oz_mode) {
|
||||
mutex_unlock(&dir->i_mutex);
|
||||
expiring = autofs4_lookup_expiring(dentry);
|
||||
mutex_unlock(&dir->i_mutex);
|
||||
if (expiring) {
|
||||
/*
|
||||
* If we are racing with expire the request might not
|
||||
|
|
@ -580,23 +744,22 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
|
|||
* so it must have been successful, so just wait for it.
|
||||
*/
|
||||
autofs4_expire_wait(expiring);
|
||||
autofs4_del_expiring(expiring);
|
||||
dput(expiring);
|
||||
}
|
||||
|
||||
spin_lock(&sbi->fs_lock);
|
||||
ino->flags |= AUTOFS_INF_PENDING;
|
||||
spin_unlock(&sbi->fs_lock);
|
||||
if (dentry->d_op && dentry->d_op->d_revalidate)
|
||||
(dentry->d_op->d_revalidate)(dentry, nd);
|
||||
status = try_to_fill_dentry(dentry);
|
||||
mutex_lock(&dir->i_mutex);
|
||||
spin_lock(&sbi->fs_lock);
|
||||
ino->flags &= ~AUTOFS_INF_PENDING;
|
||||
spin_unlock(&sbi->fs_lock);
|
||||
}
|
||||
|
||||
autofs4_del_active(dentry);
|
||||
|
||||
/*
|
||||
* If we are still pending, check if we had to handle
|
||||
* If we had a mount fail, check if we had to handle
|
||||
* a signal. If so we can force a restart..
|
||||
*/
|
||||
if (ino->flags & AUTOFS_INF_PENDING) {
|
||||
if (status) {
|
||||
/* See if we were interrupted */
|
||||
if (signal_pending(current)) {
|
||||
sigset_t *sigset = ¤t->pending.signal;
|
||||
|
|
@ -608,43 +771,46 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
|
|||
return ERR_PTR(-ERESTARTNOINTR);
|
||||
}
|
||||
}
|
||||
if (!oz_mode) {
|
||||
spin_lock(&sbi->fs_lock);
|
||||
ino->flags &= ~AUTOFS_INF_PENDING;
|
||||
spin_unlock(&sbi->fs_lock);
|
||||
}
|
||||
|
||||
/*
|
||||
* User space can (and has done in the past) remove and re-create
|
||||
* this directory during the callback. This can leave us with an
|
||||
* unhashed dentry, but a successful mount! So we need to
|
||||
* perform another cached lookup in case the dentry now exists.
|
||||
*/
|
||||
if (!oz_mode && !have_submounts(dentry)) {
|
||||
struct dentry *new;
|
||||
new = d_lookup(dentry->d_parent, &dentry->d_name);
|
||||
if (new) {
|
||||
if (active)
|
||||
dput(active);
|
||||
return new;
|
||||
} else {
|
||||
if (!status)
|
||||
status = -ENOENT;
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* If this dentry is unhashed, then we shouldn't honour this
|
||||
* lookup. Returning ENOENT here doesn't do the right thing
|
||||
* for all system calls, but it should be OK for the operations
|
||||
* we permit from an autofs.
|
||||
* If we had a mount failure, return status to user space.
|
||||
* If the mount succeeded and we used a dentry from the active queue
|
||||
* return it.
|
||||
*/
|
||||
if (!oz_mode && d_unhashed(dentry)) {
|
||||
/*
|
||||
* A user space application can (and has done in the past)
|
||||
* remove and re-create this directory during the callback.
|
||||
* This can leave us with an unhashed dentry, but a
|
||||
* successful mount! So we need to perform another
|
||||
* cached lookup in case the dentry now exists.
|
||||
*/
|
||||
struct dentry *parent = dentry->d_parent;
|
||||
struct dentry *new = d_lookup(parent, &dentry->d_name);
|
||||
if (new != NULL)
|
||||
dentry = new;
|
||||
else
|
||||
dentry = ERR_PTR(-ENOENT);
|
||||
|
||||
if (status) {
|
||||
dentry = ERR_PTR(status);
|
||||
if (active)
|
||||
dput(active);
|
||||
|
||||
return dentry;
|
||||
} else {
|
||||
/*
|
||||
* Valid successful mount, return active dentry or NULL
|
||||
* for a new dentry.
|
||||
*/
|
||||
if (active)
|
||||
return active;
|
||||
}
|
||||
|
||||
if (active)
|
||||
return active;
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
|
|
@ -668,8 +834,6 @@ static int autofs4_dir_symlink(struct inode *dir,
|
|||
if (!ino)
|
||||
return -ENOMEM;
|
||||
|
||||
autofs4_del_active(dentry);
|
||||
|
||||
ino->size = strlen(symname);
|
||||
cp = kmalloc(ino->size + 1, GFP_KERNEL);
|
||||
if (!cp) {
|
||||
|
|
@ -746,7 +910,6 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
|
|||
dir->i_mtime = CURRENT_TIME;
|
||||
|
||||
spin_lock(&dcache_lock);
|
||||
autofs4_add_expiring(dentry);
|
||||
spin_lock(&dentry->d_lock);
|
||||
__d_drop(dentry);
|
||||
spin_unlock(&dentry->d_lock);
|
||||
|
|
@ -772,7 +935,6 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
|
|||
spin_unlock(&dcache_lock);
|
||||
return -ENOTEMPTY;
|
||||
}
|
||||
autofs4_add_expiring(dentry);
|
||||
spin_lock(&dentry->d_lock);
|
||||
__d_drop(dentry);
|
||||
spin_unlock(&dentry->d_lock);
|
||||
|
|
@ -810,8 +972,6 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
|
|||
if (!ino)
|
||||
return -ENOMEM;
|
||||
|
||||
autofs4_del_active(dentry);
|
||||
|
||||
inode = autofs4_get_inode(dir->i_sb, ino);
|
||||
if (!inode) {
|
||||
if (!dentry->d_fsdata)
|
||||
|
|
|
|||
Loading…
Reference in New Issue