#endif
static int autofs4_dir_open(struct inode *inode, struct file *file);
static struct dentry *autofs4_lookup(struct inode *,struct dentry *, struct nameidata *);
-
-#define TRIGGER_FLAGS (LOOKUP_CONTINUE | LOOKUP_DIRECTORY)
-#define TRIGGER_INTENTS (LOOKUP_OPEN | LOOKUP_CREATE)
+static struct vfsmount *autofs4_d_automount(struct path *);
+static int autofs4_d_manage(struct dentry *, bool, bool);
const struct file_operations autofs4_root_operations = {
.open = dcache_dir_open,
.llseek = dcache_dir_lseek,
};
-const struct inode_operations autofs4_indirect_root_inode_operations = {
+const struct inode_operations autofs4_dir_inode_operations = {
.lookup = autofs4_lookup,
.unlink = autofs4_dir_unlink,
.symlink = autofs4_dir_symlink,
.rmdir = autofs4_dir_rmdir,
};
-const struct inode_operations autofs4_direct_root_inode_operations = {
- .lookup = autofs4_lookup,
- .unlink = autofs4_dir_unlink,
- .mkdir = autofs4_dir_mkdir,
- .rmdir = autofs4_dir_rmdir,
-};
-
-const struct inode_operations autofs4_dir_inode_operations = {
- .lookup = autofs4_lookup,
- .unlink = autofs4_dir_unlink,
- .symlink = autofs4_dir_symlink,
- .mkdir = autofs4_dir_mkdir,
- .rmdir = autofs4_dir_rmdir,
+const struct dentry_operations autofs4_dentry_operations = {
+ .d_automount = autofs4_d_automount,
+ .d_manage = autofs4_d_manage,
+ .d_release = autofs4_dentry_release,
};
static void autofs4_add_active(struct dentry *dentry)
return;
}
-static unsigned int autofs4_need_mount(unsigned int flags)
-{
- unsigned int res = 0;
- if (flags & (TRIGGER_FLAGS | TRIGGER_INTENTS))
- res = 1;
- return res;
-}
-
static int autofs4_dir_open(struct inode *inode, struct file *file)
{
struct dentry *dentry = file->f_path.dentry;
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);
- int status;
-
- DPRINTK("dentry=%p %.*s ino=%p",
- dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
-
- /*
- * Wait for a pending mount, triggering one if there
- * isn't one already
- */
- if (dentry->d_inode == NULL) {
- DPRINTK("waiting for mount name=%.*s",
- dentry->d_name.len, dentry->d_name.name);
-
- status = autofs4_wait(sbi, dentry, NFY_MOUNT);
-
- DPRINTK("mount done status=%d", status);
-
- /* Turn this into a real negative dentry? */
- if (status == -ENOENT) {
- spin_lock(&sbi->fs_lock);
- ino->flags &= ~AUTOFS_INF_PENDING;
- spin_unlock(&sbi->fs_lock);
- return status;
- } else if (status) {
- /* Return a negative dentry, but leave it "pending" */
- return status;
- }
- /* Trigger mount for path component or follow link */
- } else if (ino->flags & AUTOFS_INF_PENDING ||
- autofs4_need_mount(flags)) {
- DPRINTK("waiting for mount name=%.*s",
- dentry->d_name.len, dentry->d_name.name);
-
- spin_lock(&sbi->fs_lock);
- ino->flags |= AUTOFS_INF_PENDING;
- spin_unlock(&sbi->fs_lock);
- status = autofs4_wait(sbi, dentry, NFY_MOUNT);
-
- DPRINTK("mount done status=%d", status);
-
- if (status) {
- spin_lock(&sbi->fs_lock);
- ino->flags &= ~AUTOFS_INF_PENDING;
- spin_unlock(&sbi->fs_lock);
- return status;
- }
- }
-
- /* Initialize expiry counter after successful mount */
- ino->last_used = jiffies;
-
- spin_lock(&sbi->fs_lock);
- ino->flags &= ~AUTOFS_INF_PENDING;
- spin_unlock(&sbi->fs_lock);
-
- return 0;
-}
-
-/* For autofs direct mounts the follow link triggers the mount */
-static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
-{
- struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
- struct autofs_info *ino = autofs4_dentry_ino(dentry);
- int oz_mode = autofs4_oz_mode(sbi);
- unsigned int lookup_type;
- int status;
-
- DPRINTK("dentry=%p %.*s oz_mode=%d nd->flags=%d",
- dentry, dentry->d_name.len, dentry->d_name.name, oz_mode,
- nd->flags);
- /*
- * For an expire of a covered direct or offset mount we need
- * to break out of follow_down_one() at the autofs mount trigger
- * (d_mounted--), so we can see the expiring flag, and manage
- * the blocking and following here until the expire is completed.
- */
- if (oz_mode) {
- spin_lock(&sbi->fs_lock);
- if (ino->flags & AUTOFS_INF_EXPIRING) {
- spin_unlock(&sbi->fs_lock);
- /* Follow down to our covering mount. */
- if (!follow_down_one(&nd->path))
- goto done;
- goto follow;
- }
- spin_unlock(&sbi->fs_lock);
- goto done;
- }
-
- /* If an expire request is pending everyone must wait. */
- autofs4_expire_wait(dentry);
-
- /* We trigger a mount for almost all flags */
- lookup_type = autofs4_need_mount(nd->flags);
- spin_lock(&sbi->fs_lock);
- spin_lock(&autofs4_lock);
- spin_lock(&dentry->d_lock);
- if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) {
- spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
- spin_unlock(&sbi->fs_lock);
- goto follow;
- }
-
- /*
- * If the dentry contains directories then it is an autofs
- * multi-mount with no root mount offset. So don't try to
- * mount it again.
- */
- if (ino->flags & AUTOFS_INF_PENDING ||
- (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
- spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
- spin_unlock(&sbi->fs_lock);
-
- status = try_to_fill_dentry(dentry, nd->flags);
- if (status)
- goto out_error;
-
- goto follow;
- }
- spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
- spin_unlock(&sbi->fs_lock);
-follow:
- /*
- * If there is no root mount it must be an autofs
- * multi-mount with no root offset so we don't need
- * to follow it.
- */
- if (d_managed(dentry)) {
- status = follow_down(&nd->path, false);
- if (status < 0)
- goto out_error;
- }
-
-done:
- return NULL;
-
-out_error:
- path_put(&nd->path);
- return ERR_PTR(status);
-}
-
-/*
- * Revalidate is called on every cache lookup. Some of those
- * cache lookups may actually happen while the dentry is not
- * yet completely filled in, and revalidate has to delay such
- * lookups..
- */
-static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
-{
- struct inode *dir;
- struct autofs_sb_info *sbi;
- int oz_mode;
- int flags = nd ? nd->flags : 0;
- int status = 1;
-
- if (flags & LOOKUP_RCU)
- return -ECHILD;
-
- dir = dentry->d_parent->d_inode;
- sbi = autofs4_sbi(dir->i_sb);
- oz_mode = autofs4_oz_mode(sbi);
-
- /* Pending dentry */
- spin_lock(&sbi->fs_lock);
- if (autofs4_ispending(dentry)) {
- /* The daemon never causes a mount to trigger */
- spin_unlock(&sbi->fs_lock);
-
- if (oz_mode)
- return 1;
-
- /*
- * If the directory has gone away due to an expire
- * we have been called as ->d_revalidate() and so
- * we need to return false and proceed to ->lookup().
- */
- if (autofs4_expire_wait(dentry) == -EAGAIN)
- return 0;
-
- /*
- * A zero status is success otherwise we have a
- * negative error code.
- */
- status = try_to_fill_dentry(dentry, flags);
- if (status == 0)
- return 1;
-
- return status;
- }
- spin_unlock(&sbi->fs_lock);
-
- /* Negative dentry.. invalidate if "old" */
- if (dentry->d_inode == NULL)
- return 0;
-
- /* Check for a non-mountpoint directory with no contents */
- spin_lock(&autofs4_lock);
- spin_lock(&dentry->d_lock);
- if (S_ISDIR(dentry->d_inode->i_mode) &&
- !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
- DPRINTK("dentry=%p %.*s, emptydir",
- dentry, dentry->d_name.len, dentry->d_name.name);
- spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
-
- /* The daemon never causes a mount to trigger */
- if (oz_mode)
- return 1;
-
- /*
- * A zero status is success otherwise we have a
- * negative error code.
- */
- status = try_to_fill_dentry(dentry, flags);
- if (status == 0)
- return 1;
-
- return status;
- }
- spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
-
- return 1;
-}
-
void autofs4_dentry_release(struct dentry *de)
{
struct autofs_info *inf;
DPRINTK("releasing %p", de);
inf = autofs4_dentry_ino(de);
- de->d_fsdata = NULL;
-
if (inf) {
struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);
-
if (sbi) {
spin_lock(&sbi->lookup_lock);
if (!list_empty(&inf->active))
list_del(&inf->expiring);
spin_unlock(&sbi->lookup_lock);
}
-
- inf->dentry = NULL;
- inf->inode = NULL;
-
autofs4_free_ino(inf);
}
}
-/* For dentries of directories in the root dir */
-static const struct dentry_operations autofs4_root_dentry_operations = {
- .d_release = autofs4_dentry_release,
-};
-
-/* For other dentries */
-static const struct dentry_operations autofs4_dentry_operations = {
- .d_automount = autofs4_d_automount,
- .d_manage = autofs4_d_manage,
- .d_release = autofs4_dentry_release,
-};
-
static struct dentry *autofs4_lookup_active(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
return path->dentry;
}
-struct vfsmount *autofs4_d_automount(struct path *path)
+static struct vfsmount *autofs4_d_automount(struct path *path)
{
struct dentry *dentry = path->dentry;
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
return NULL;
}
-int autofs4_d_manage(struct dentry *dentry, bool mounting_here)
+int autofs4_d_manage(struct dentry *dentry, bool mounting_here, bool rcu_walk)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
return 0;
}
+ /* We need to sleep, so we need pathwalk to be in ref-mode */
+ if (rcu_walk)
+ return -ECHILD;
+
/* Wait for pending expires */
do_expire_wait(dentry);
sbi = autofs4_sbi(dir->i_sb);
DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
- current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
+ current->pid, task_pgrp_nr(current), sbi->catatonic,
+ autofs4_oz_mode(sbi));
active = autofs4_lookup_active(dentry);
if (active) {
return active;
} else {
- d_set_d_op(dentry, &autofs4_root_dentry_operations);
-
/*
* A dentry that is not within the root can never trigger a
* mount operation, unless the directory already exists, so we
return ERR_PTR(-ENOENT);
/* Mark entries in the root as mount triggers */
- if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent)) {
- d_set_d_op(dentry, &autofs4_dentry_operations);
+ if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent))
__managed_dentry_set_managed(dentry);
- }
- ino = autofs4_init_ino(NULL, sbi, 0555);
+ ino = autofs4_init_ino(NULL, sbi);
if (!ino)
return ERR_PTR(-ENOMEM);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
struct autofs_info *p_ino;
struct inode *inode;
+ size_t size = strlen(symname);
char *cp;
DPRINTK("%s <- %.*s", symname,
if (!autofs4_oz_mode(sbi))
return -EACCES;
- ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555);
- if (!ino)
- return -ENOMEM;
+ BUG_ON(!ino);
+
+ autofs4_init_ino(ino, sbi);
autofs4_del_active(dentry);
- ino->size = strlen(symname);
- cp = kmalloc(ino->size + 1, GFP_KERNEL);
- if (!cp) {
- if (!dentry->d_fsdata)
- kfree(ino);
+ cp = kmalloc(size + 1, GFP_KERNEL);
+ if (!cp)
return -ENOMEM;
- }
strcpy(cp, symname);
- inode = autofs4_get_inode(dir->i_sb, ino);
+ inode = autofs4_get_inode(dir->i_sb, S_IFLNK | 0555);
if (!inode) {
kfree(cp);
if (!dentry->d_fsdata)
kfree(ino);
return -ENOMEM;
}
+ inode->i_private = cp;
+ inode->i_size = size;
d_add(dentry, inode);
- dentry->d_fsdata = ino;
- ino->dentry = dget(dentry);
+ dget(dentry);
atomic_inc(&ino->count);
p_ino = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && dentry->d_parent != dentry)
atomic_inc(&p_ino->count);
- ino->inode = inode;
- ino->u.symlink = cp;
dir->i_mtime = CURRENT_TIME;
return 0;
return 0;
}
+/*
+ * Version 4 of autofs provides a pseudo direct mount implementation
+ * that relies on directories at the leaves of a directory tree under
+ * an indirect mount to trigger mounts. To allow for this we need to
+ * set the DMANAGED_AUTOMOUNT and DMANAGED_TRANSIT flags on the leaves
+ * of the directory tree. There is no need to clear the automount flag
+ * following a mount or restore it after an expire because these mounts
+ * are always covered. However, it is neccessary to ensure that these
+ * flags are clear on non-empty directories to avoid unnecessary calls
+ * during path walks.
+ */
+static void autofs_set_leaf_automount_flags(struct dentry *dentry)
+{
+ struct dentry *parent;
+
+ /* root and dentrys in the root are already handled */
+ if (IS_ROOT(dentry->d_parent))
+ return;
+
+ managed_dentry_set_managed(dentry);
+
+ parent = dentry->d_parent;
+ /* only consider parents below dentrys in the root */
+ if (IS_ROOT(parent->d_parent))
+ return;
+ managed_dentry_clear_managed(parent);
+ return;
+}
+
+static void autofs_clear_leaf_automount_flags(struct dentry *dentry)
+{
+ struct list_head *d_child;
+ struct dentry *parent;
+
+ /* flags for dentrys in the root are handled elsewhere */
+ if (IS_ROOT(dentry->d_parent))
+ return;
+
+ managed_dentry_clear_managed(dentry);
+
+ parent = dentry->d_parent;
+ /* only consider parents below dentrys in the root */
+ if (IS_ROOT(parent->d_parent))
+ return;
+ d_child = &dentry->d_u.d_child;
+ /* Set parent managed if it's becoming empty */
+ if (d_child->next == &parent->d_subdirs &&
+ d_child->prev == &parent->d_subdirs)
+ managed_dentry_set_managed(parent);
+ return;
+}
+
static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
spin_unlock(&dentry->d_lock);
spin_unlock(&autofs4_lock);
+ if (sbi->version < 5)
+ autofs_clear_leaf_automount_flags(dentry);
+
if (atomic_dec_and_test(&ino->count)) {
p_ino = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && dentry->d_parent != dentry)
DPRINTK("dentry %p, creating %.*s",
dentry, dentry->d_name.len, dentry->d_name.name);
- ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555);
- if (!ino)
- return -ENOMEM;
+ BUG_ON(!ino);
+
+ autofs4_init_ino(ino, sbi);
autofs4_del_active(dentry);
- inode = autofs4_get_inode(dir->i_sb, ino);
- if (!inode) {
- if (!dentry->d_fsdata)
- kfree(ino);
+ inode = autofs4_get_inode(dir->i_sb, S_IFDIR | 0555);
+ if (!inode)
return -ENOMEM;
- }
d_add(dentry, inode);
- dentry->d_fsdata = ino;
- ino->dentry = dget(dentry);
+ if (sbi->version < 5)
+ autofs_set_leaf_automount_flags(dentry);
+
+ dget(dentry);
atomic_inc(&ino->count);
p_ino = autofs4_dentry_ino(dentry->d_parent);
if (p_ino && dentry->d_parent != dentry)
atomic_inc(&p_ino->count);
- ino->inode = inode;
inc_nlink(dir);
dir->i_mtime = CURRENT_TIME;
int is_autofs4_dentry(struct dentry *dentry)
{
return dentry && dentry->d_inode &&
- (dentry->d_op == &autofs4_root_dentry_operations ||
- dentry->d_op == &autofs4_dentry_operations) &&
+ dentry->d_op == &autofs4_dentry_operations &&
dentry->d_fsdata != NULL;
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff