static int autofs4_dir_mkdir(struct inode *,struct dentry *,int);
static int autofs4_root_ioctl(struct inode *, struct file *,unsigned int,unsigned long);
static int autofs4_dir_open(struct inode *inode, struct file *file);
-static int autofs4_dir_close(struct inode *inode, struct file *file);
-static int autofs4_dir_readdir(struct file * filp, void * dirent, filldir_t filldir);
static int autofs4_root_readdir(struct file * filp, void * dirent, filldir_t filldir);
static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
static void *autofs4_follow_link(struct dentry *, struct nameidata *);
+#define TRIGGER_FLAGS (LOOKUP_CONTINUE | LOOKUP_DIRECTORY)
+#define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE)
+
const struct file_operations autofs4_root_operations = {
.open = dcache_dir_open,
.release = dcache_dir_close,
const struct file_operations autofs4_dir_operations = {
.open = autofs4_dir_open,
- .release = autofs4_dir_close,
+ .release = dcache_dir_close,
.read = generic_read_dir,
- .readdir = autofs4_dir_readdir,
+ .readdir = dcache_readdir,
};
const struct inode_operations autofs4_indirect_root_inode_operations = {
static int autofs4_dir_open(struct inode *inode, struct file *file)
{
struct dentry *dentry = file->f_path.dentry;
- struct vfsmount *mnt = file->f_path.mnt;
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
- struct dentry *cursor;
- int status;
-
- status = dcache_dir_open(inode, file);
- if (status)
- goto out;
-
- cursor = file->private_data;
- cursor->d_fsdata = NULL;
DPRINTK("file=%p dentry=%p %.*s",
file, dentry, dentry->d_name.len, dentry->d_name.name);
if (autofs4_oz_mode(sbi))
goto out;
- if (autofs4_ispending(dentry)) {
- DPRINTK("dentry busy");
- dcache_dir_close(inode, file);
- status = -EBUSY;
- goto out;
- }
-
- status = -ENOENT;
- if (!d_mountpoint(dentry) && dentry->d_op && dentry->d_op->d_revalidate) {
- struct nameidata nd;
- int empty, ret;
-
- /* In case there are stale directory dentrys from a failed mount */
- spin_lock(&dcache_lock);
- empty = list_empty(&dentry->d_subdirs);
+ /*
+ * An empty directory in an autofs file system is always a
+ * mount point. The daemon must have failed to mount this
+ * during lookup so it doesn't exist. This can happen, for
+ * example, if user space returns an incorrect status for a
+ * mount request. Otherwise we're doing a readdir on the
+ * autofs file system so just let the libfs routines handle
+ * it.
+ */
+ spin_lock(&dcache_lock);
+ if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
spin_unlock(&dcache_lock);
-
- if (!empty)
- d_invalidate(dentry);
-
- nd.flags = LOOKUP_DIRECTORY;
- ret = (dentry->d_op->d_revalidate)(dentry, &nd);
-
- if (ret <= 0) {
- if (ret < 0)
- status = ret;
- dcache_dir_close(inode, file);
- goto out;
- }
- }
-
- if (d_mountpoint(dentry)) {
- struct file *fp = NULL;
- struct path fp_path = { .dentry = dentry, .mnt = mnt };
-
- path_get(&fp_path);
-
- if (!autofs4_follow_mount(&fp_path.mnt, &fp_path.dentry)) {
- path_put(&fp_path);
- dcache_dir_close(inode, file);
- goto out;
- }
-
- fp = dentry_open(fp_path.dentry, fp_path.mnt, file->f_flags);
- status = PTR_ERR(fp);
- if (IS_ERR(fp)) {
- dcache_dir_close(inode, file);
- goto out;
- }
- cursor->d_fsdata = fp;
- }
- return 0;
-out:
- return status;
-}
-
-static int autofs4_dir_close(struct inode *inode, struct file *file)
-{
- struct dentry *dentry = file->f_path.dentry;
- struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
- struct dentry *cursor = file->private_data;
- int status = 0;
-
- DPRINTK("file=%p dentry=%p %.*s",
- file, dentry, dentry->d_name.len, dentry->d_name.name);
-
- if (autofs4_oz_mode(sbi))
- goto out;
-
- if (autofs4_ispending(dentry)) {
- DPRINTK("dentry busy");
- status = -EBUSY;
- goto out;
- }
-
- if (d_mountpoint(dentry)) {
- struct file *fp = cursor->d_fsdata;
- if (!fp) {
- status = -ENOENT;
- goto out;
- }
- filp_close(fp, current->files);
- }
-out:
- dcache_dir_close(inode, file);
- return status;
-}
-
-static int autofs4_dir_readdir(struct file *file, void *dirent, filldir_t filldir)
-{
- struct dentry *dentry = file->f_path.dentry;
- struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
- struct dentry *cursor = file->private_data;
- int status;
-
- DPRINTK("file=%p dentry=%p %.*s",
- file, dentry, dentry->d_name.len, dentry->d_name.name);
-
- if (autofs4_oz_mode(sbi))
- goto out;
-
- if (autofs4_ispending(dentry)) {
- DPRINTK("dentry busy");
- return -EBUSY;
+ return -ENOENT;
}
+ spin_unlock(&dcache_lock);
- if (d_mountpoint(dentry)) {
- struct file *fp = cursor->d_fsdata;
-
- if (!fp)
- return -ENOENT;
-
- if (!fp->f_op || !fp->f_op->readdir)
- goto out;
-
- status = vfs_readdir(fp, filldir, dirent);
- file->f_pos = fp->f_pos;
- if (status)
- autofs4_copy_atime(file, fp);
- return status;
- }
out:
- return dcache_readdir(file, dirent, filldir);
+ return dcache_dir_open(inode, file);
}
static int try_to_fill_dentry(struct dentry *dentry, int flags)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
- struct dentry *new;
int status;
/* Block on any pending expiry here; invalidate the dentry
return status;
}
/* Trigger mount for path component or follow link */
- } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) ||
+ } else if (flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) ||
current->link_count) {
DPRINTK("waiting for mount name=%.*s",
dentry->d_name.len, dentry->d_name.name);
dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
- /*
- * The dentry that is passed in from lookup may not be the one
- * we end up using, as mkdir can create a new one. If this
- * happens, and another process tries the lookup at the same time,
- * it will set the PENDING flag on this new dentry, but add itself
- * to our waitq. Then, if after the lookup succeeds, the first
- * process that requested the mount performs another lookup of the
- * same directory, it will show up as still pending! So, we need
- * to redo the lookup here and clear pending on that dentry.
- */
- if (d_unhashed(dentry)) {
- new = d_lookup(dentry->d_parent, &dentry->d_name);
- if (new) {
- spin_lock(&new->d_lock);
- new->d_flags &= ~DCACHE_AUTOFS_PENDING;
- spin_unlock(&new->d_lock);
- dput(new);
- }
- }
-
return 0;
}
nd->flags);
/* If it's our master or we shouldn't trigger a mount we're done */
- lookup_type = nd->flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY);
+ lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS);
if (oz_mode || !lookup_type)
goto done;
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);
.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;
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",
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,
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;
- dentry->d_fsdata = NULL;
- d_instantiate(dentry, NULL);
+ spin_lock(&sbi->lookup_lock);
+ list_add(&ino->active, &sbi->active_list);
+ spin_unlock(&sbi->lookup_lock);
+
+ d_instantiate(dentry, NULL);
+ }
if (!oz_mode) {
spin_lock(&dentry->d_lock);
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
spin_unlock(&dentry->d_lock);
- }
-
- if (dentry->d_op && dentry->d_op->d_revalidate) {
- mutex_unlock(&dir->i_mutex);
- (dentry->d_op->d_revalidate)(dentry, nd);
- mutex_lock(&dir->i_mutex);
+ if (dentry->d_op && dentry->d_op->d_revalidate) {
+ mutex_unlock(&dir->i_mutex);
+ (dentry->d_op->d_revalidate)(dentry, nd);
+ mutex_lock(&dir->i_mutex);
+ }
}
/*
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);
+ }
}
/*
else
dentry = ERR_PTR(-ENOENT);
+ if (unhashed)
+ dput(unhashed);
+
return dentry;
}
+ if (unhashed)
+ return unhashed;
+
return NULL;
}
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;
+ ino->size = strlen(symname);
+ 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)
atomic_inc(&p_ino->count);
ino->inode = inode;
+ ino->u.symlink = cp;
dir->i_mtime = CURRENT_TIME;
return 0;
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);
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);
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)
projects / linux-2.6-omap-h63xx.git / blobdiff