* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (23 commits)
sanitize vfsmount refcounting changes
fix old umount_tree() breakage
autofs4: Merge the remaining dentry ops tables
Unexport do_add_mount() and add in follow_automount(), not ->d_automount()
Allow d_manage() to be used in RCU-walk mode
Remove a further kludge from __do_follow_link()
autofs4: Bump version
autofs4: Add v4 pseudo direct mount support
autofs4: Fix wait validation
autofs4: Clean up autofs4_free_ino()
autofs4: Clean up dentry operations
autofs4: Clean up inode operations
autofs4: Remove unused code
autofs4: Add d_manage() dentry operation
autofs4: Add d_automount() dentry operation
Remove the automount through follow_link() kludge code from pathwalk
CIFS: Use d_automount() rather than abusing follow_link()
NFS: Use d_automount() rather than abusing follow_link()
AFS: Use d_automount() rather than abusing follow_link()
Add an AT_NO_AUTOMOUNT flag to suppress terminal automount
...
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen);
+ struct vfsmount *(*d_automount)(struct path *path);
+ int (*d_manage)(struct dentry *, bool);
locking rules:
rename_lock ->d_lock may block rcu-walk
d_release: no no yes no
d_iput: no no yes no
d_dname: no no no no
+d_automount: no no yes no
+d_manage: no no yes (ref-walk) maybe
--------------------------- inode_operations ---------------------------
prototypes:
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)(struct dentry *, char *, int);
+ struct vfsmount *(*d_automount)(struct path *);
+ int (*d_manage)(struct dentry *, bool, bool);
};
d_revalidate: called when the VFS needs to revalidate a dentry. This
at the end of the buffer, and returns a pointer to the first char.
dynamic_dname() helper function is provided to take care of this.
+ d_automount: called when an automount dentry is to be traversed (optional).
+ This should create a new VFS mount record and return the record to the
+ caller. The caller is supplied with a path parameter giving the
+ automount directory to describe the automount target and the parent
+ VFS mount record to provide inheritable mount parameters. NULL should
+ be returned if someone else managed to make the automount first. If
+ the vfsmount creation failed, then an error code should be returned.
+ If -EISDIR is returned, then the directory will be treated as an
+ ordinary directory and returned to pathwalk to continue walking.
+
+ If a vfsmount is returned, the caller will attempt to mount it on the
+ mountpoint and will remove the vfsmount from its expiration list in
+ the case of failure. The vfsmount should be returned with 2 refs on
+ it to prevent automatic expiration - the caller will clean up the
+ additional ref.
+
+ This function is only used if DCACHE_NEED_AUTOMOUNT is set on the
+ dentry. This is set by __d_instantiate() if S_AUTOMOUNT is set on the
+ inode being added.
+
+ d_manage: called to allow the filesystem to manage the transition from a
+ dentry (optional). This allows autofs, for example, to hold up clients
+ waiting to explore behind a 'mountpoint' whilst letting the daemon go
+ past and construct the subtree there. 0 should be returned to let the
+ calling process continue. -EISDIR can be returned to tell pathwalk to
+ use this directory as an ordinary directory and to ignore anything
+ mounted on it and not to check the automount flag. Any other error
+ code will abort pathwalk completely.
+
+ If the 'mounting_here' parameter is true, then namespace_sem is being
+ held by the caller and the function should not initiate any mounts or
+ unmounts that it will then wait for.
+
+ If the 'rcu_walk' parameter is true, then the caller is doing a
+ pathwalk in RCU-walk mode. Sleeping is not permitted in this mode,
+ and the caller can be asked to leave it and call again by returing
+ -ECHILD.
+
+ This function is only used if DCACHE_MANAGE_TRANSIT is set on the
+ dentry being transited from.
+
Example :
static char *pipefs_dname(struct dentry *dent, char *buffer, int buflen)
static void __exit cleanup_mtdchar(void)
{
unregister_mtd_user(&mtdchar_notifier);
- mntput_long(mtd_inode_mnt);
+ mntput(mtd_inode_mnt);
unregister_filesystem(&mtd_inodefs_type);
__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
}
}
path.mnt = mnt;
path_get(&path);
- if (!follow_down(&path)) {
+ if (!follow_down_one(&path)) {
path_put(&path);
DPRINTK(("autofs: not expirable\
(not a mounted directory): %s\n", ent->name));
continue;
}
- while (d_mountpoint(path.dentry) && follow_down(&path))
- ;
+ follow_down(&path, false); // TODO: need to check error
umount_ok = may_umount(path.mnt);
path_put(&path);
.d_revalidate = afs_d_revalidate,
.d_delete = afs_d_delete,
.d_release = afs_d_release,
+ .d_automount = afs_d_automount,
};
#define AFS_DIR_HASHTBL_SIZE 128
inode->i_generation = 0;
set_bit(AFS_VNODE_PSEUDODIR, &vnode->flags);
- inode->i_flags |= S_NOATIME;
+ set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
+ inode->i_flags |= S_AUTOMOUNT | S_NOATIME;
unlock_new_inode(inode);
_leave(" = %p", inode);
return inode;
extern const struct inode_operations afs_autocell_inode_operations;
extern const struct file_operations afs_mntpt_file_operations;
+extern struct vfsmount *afs_d_automount(struct path *);
extern int afs_mntpt_check_symlink(struct afs_vnode *, struct key *);
extern void afs_mntpt_kill_timer(void);
struct dentry *dentry,
struct nameidata *nd);
static int afs_mntpt_open(struct inode *inode, struct file *file);
-static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd);
static void afs_mntpt_expiry_timed_out(struct work_struct *work);
const struct file_operations afs_mntpt_file_operations = {
const struct inode_operations afs_mntpt_inode_operations = {
.lookup = afs_mntpt_lookup,
- .follow_link = afs_mntpt_follow_link,
.readlink = page_readlink,
.getattr = afs_getattr,
};
const struct inode_operations afs_autocell_inode_operations = {
- .follow_link = afs_mntpt_follow_link,
.getattr = afs_getattr,
};
_debug("symlink is a mountpoint");
spin_lock(&vnode->lock);
set_bit(AFS_VNODE_MOUNTPOINT, &vnode->flags);
+ vnode->vfs_inode.i_flags |= S_AUTOMOUNT;
spin_unlock(&vnode->lock);
}
}
/*
- * follow a link from a mountpoint directory, thus causing it to be mounted
+ * handle an automount point
*/
-static void *afs_mntpt_follow_link(struct dentry *dentry, struct nameidata *nd)
+struct vfsmount *afs_d_automount(struct path *path)
{
struct vfsmount *newmnt;
- int err;
- _enter("%p{%s},{%s:%p{%s},}",
- dentry,
- dentry->d_name.name,
- nd->path.mnt->mnt_devname,
- dentry,
- nd->path.dentry->d_name.name);
-
- dput(nd->path.dentry);
- nd->path.dentry = dget(dentry);
-
- newmnt = afs_mntpt_do_automount(nd->path.dentry);
- if (IS_ERR(newmnt)) {
- path_put(&nd->path);
- return (void *)newmnt;
- }
+ _enter("{%s,%s}", path->mnt->mnt_devname, path->dentry->d_name.name);
- mntget(newmnt);
- err = do_add_mount(newmnt, &nd->path, MNT_SHRINKABLE, &afs_vfsmounts);
- switch (err) {
- case 0:
- path_put(&nd->path);
- nd->path.mnt = newmnt;
- nd->path.dentry = dget(newmnt->mnt_root);
- queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
- afs_mntpt_expiry_timeout * HZ);
- break;
- case -EBUSY:
- /* someone else made a mount here whilst we were busy */
- while (d_mountpoint(nd->path.dentry) &&
- follow_down(&nd->path))
- ;
- err = 0;
- default:
- mntput(newmnt);
- break;
- }
+ newmnt = afs_mntpt_do_automount(path->dentry);
+ if (IS_ERR(newmnt))
+ return newmnt;
- _leave(" = %d", err);
- return ERR_PTR(err);
+ mntget(newmnt); /* prevent immediate expiration */
+ mnt_set_expiry(newmnt, &afs_vfsmounts);
+ queue_delayed_work(afs_wq, &afs_mntpt_expiry_timer,
+ afs_mntpt_expiry_timeout * HZ);
+ _leave(" = %p {%s}", newmnt, newmnt->mnt_devname);
+ return newmnt;
}
/*
return 0;
err_mntput:
- mntput_long(anon_inode_mnt);
+ mntput(anon_inode_mnt);
err_unregister_filesystem:
unregister_filesystem(&anon_inode_fs_type);
err_exit:
};
#define AUTOFS_INF_EXPIRING (1<<0) /* dentry is in the process of expiring */
-#define AUTOFS_INF_MOUNTPOINT (1<<1) /* mountpoint status for direct expire */
#define AUTOFS_INF_PENDING (1<<2) /* dentry pending mount */
struct autofs_wait_queue {
return 0;
}
-static inline void autofs4_copy_atime(struct file *src, struct file *dst)
-{
- dst->f_path.dentry->d_inode->i_atime =
- src->f_path.dentry->d_inode->i_atime;
- return;
-}
-
struct inode *autofs4_get_inode(struct super_block *, struct autofs_info *);
void autofs4_free_ino(struct autofs_info *);
extern const struct inode_operations autofs4_symlink_inode_operations;
extern const struct inode_operations autofs4_dir_inode_operations;
-extern const struct inode_operations autofs4_root_inode_operations;
-extern const struct inode_operations autofs4_indirect_root_inode_operations;
-extern const struct inode_operations autofs4_direct_root_inode_operations;
extern const struct file_operations autofs4_dir_operations;
extern const struct file_operations autofs4_root_operations;
+extern const struct dentry_operations autofs4_dentry_operations;
+
+/* VFS automount flags management functions */
+
+static inline void __managed_dentry_set_automount(struct dentry *dentry)
+{
+ dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
+}
+
+static inline void managed_dentry_set_automount(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_set_automount(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+
+static inline void __managed_dentry_clear_automount(struct dentry *dentry)
+{
+ dentry->d_flags &= ~DCACHE_NEED_AUTOMOUNT;
+}
+
+static inline void managed_dentry_clear_automount(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_clear_automount(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+
+static inline void __managed_dentry_set_transit(struct dentry *dentry)
+{
+ dentry->d_flags |= DCACHE_MANAGE_TRANSIT;
+}
+
+static inline void managed_dentry_set_transit(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_set_transit(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+
+static inline void __managed_dentry_clear_transit(struct dentry *dentry)
+{
+ dentry->d_flags &= ~DCACHE_MANAGE_TRANSIT;
+}
+
+static inline void managed_dentry_clear_transit(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_clear_transit(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+
+static inline void __managed_dentry_set_managed(struct dentry *dentry)
+{
+ dentry->d_flags |= (DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
+}
+
+static inline void managed_dentry_set_managed(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_set_managed(dentry);
+ spin_unlock(&dentry->d_lock);
+}
+
+static inline void __managed_dentry_clear_managed(struct dentry *dentry)
+{
+ dentry->d_flags &= ~(DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT);
+}
+
+static inline void managed_dentry_clear_managed(struct dentry *dentry)
+{
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_clear_managed(dentry);
+ spin_unlock(&dentry->d_lock);
+}
/* Initializing function */
int autofs4_wait_release(struct autofs_sb_info *,autofs_wqt_t,int);
void autofs4_catatonic_mode(struct autofs_sb_info *);
-static inline int autofs4_follow_mount(struct path *path)
-{
- int res = 0;
-
- while (d_mountpoint(path->dentry)) {
- int followed = follow_down(path);
- if (!followed)
- break;
- res = 1;
- }
- return res;
-}
-
static inline u32 autofs4_get_dev(struct autofs_sb_info *sbi)
{
return new_encode_dev(sbi->sb->s_dev);
err = have_submounts(path.dentry);
- if (follow_down(&path))
+ if (follow_down_one(&path))
magic = path.mnt->mnt_sb->s_magic;
}
if (ino == NULL)
return 0;
- /* No point expiring a pending mount */
- if (ino->flags & AUTOFS_INF_PENDING)
- return 0;
-
if (!do_now) {
/* Too young to die */
if (!timeout || time_after(ino->last_used + timeout, now))
path_get(&path);
- if (!follow_down(&path))
+ if (!follow_down_one(&path))
goto done;
if (is_autofs4_dentry(path.dentry)) {
unsigned long timeout;
struct dentry *root = dget(sb->s_root);
int do_now = how & AUTOFS_EXP_IMMEDIATE;
+ struct autofs_info *ino;
if (!root)
return NULL;
timeout = sbi->exp_timeout;
spin_lock(&sbi->fs_lock);
+ ino = autofs4_dentry_ino(root);
+ /* No point expiring a pending mount */
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ spin_unlock(&sbi->fs_lock);
+ return NULL;
+ }
+ managed_dentry_set_transit(root);
if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
struct autofs_info *ino = autofs4_dentry_ino(root);
- if (d_mountpoint(root)) {
- ino->flags |= AUTOFS_INF_MOUNTPOINT;
- spin_lock(&root->d_lock);
- root->d_flags &= ~DCACHE_MOUNTED;
- spin_unlock(&root->d_lock);
- }
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
return root;
}
+ managed_dentry_clear_transit(root);
spin_unlock(&sbi->fs_lock);
dput(root);
while ((dentry = get_next_positive_dentry(dentry, root))) {
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
+ /* No point expiring a pending mount */
+ if (ino->flags & AUTOFS_INF_PENDING)
+ goto cont;
+ managed_dentry_set_transit(dentry);
/*
* Case 1: (i) indirect mount or top level pseudo direct mount
}
}
next:
+ managed_dentry_clear_transit(dentry);
+cont:
spin_unlock(&sbi->fs_lock);
}
return NULL;
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
ino->flags &= ~AUTOFS_INF_EXPIRING;
+ if (!d_unhashed(dentry))
+ managed_dentry_clear_transit(dentry);
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
ret = autofs4_wait(sbi, dentry, NFY_EXPIRE);
spin_lock(&sbi->fs_lock);
- if (ino->flags & AUTOFS_INF_MOUNTPOINT) {
- spin_lock(&sb->s_root->d_lock);
- /*
- * If we haven't been expired away, then reset
- * mounted status.
- */
- if (mnt->mnt_parent != mnt)
- sb->s_root->d_flags |= DCACHE_MOUNTED;
- spin_unlock(&sb->s_root->d_lock);
- ino->flags &= ~AUTOFS_INF_MOUNTPOINT;
- }
ino->flags &= ~AUTOFS_INF_EXPIRING;
+ spin_lock(&dentry->d_lock);
+ if (ret)
+ __managed_dentry_clear_transit(dentry);
+ else {
+ if ((IS_ROOT(dentry) ||
+ (autofs_type_indirect(sbi->type) &&
+ IS_ROOT(dentry->d_parent))) &&
+ !(dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
+ __managed_dentry_set_automount(dentry);
+ }
+ spin_unlock(&dentry->d_lock);
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
dput(dentry);
if (!reinit) {
ino->flags = 0;
- ino->inode = NULL;
ino->dentry = NULL;
ino->size = 0;
INIT_LIST_HEAD(&ino->active);
void autofs4_free_ino(struct autofs_info *ino)
{
- struct autofs_info *p_ino;
-
if (ino->dentry) {
ino->dentry->d_fsdata = NULL;
- if (ino->dentry->d_inode) {
- struct dentry *parent = ino->dentry->d_parent;
- if (atomic_dec_and_test(&ino->count)) {
- p_ino = autofs4_dentry_ino(parent);
- if (p_ino && parent != ino->dentry)
- atomic_dec(&p_ino->count);
- }
- dput(ino->dentry);
- }
ino->dentry = NULL;
}
if (ino->free)
return ino;
}
-static const struct dentry_operations autofs4_sb_dentry_operations = {
- .d_release = autofs4_dentry_release,
-};
-
int autofs4_fill_super(struct super_block *s, void *data, int silent)
{
struct inode * root_inode;
s->s_blocksize_bits = 10;
s->s_magic = AUTOFS_SUPER_MAGIC;
s->s_op = &autofs4_sops;
+ s->s_d_op = &autofs4_dentry_operations;
s->s_time_gran = 1;
/*
goto fail_iput;
pipe = NULL;
- d_set_d_op(root, &autofs4_sb_dentry_operations);
root->d_fsdata = ino;
/* Can this call block? */
goto fail_dput;
}
+ if (autofs_type_trigger(sbi->type))
+ __managed_dentry_set_managed(root);
+
root_inode->i_fop = &autofs4_root_operations;
- root_inode->i_op = autofs_type_trigger(sbi->type) ?
- &autofs4_direct_root_inode_operations :
- &autofs4_indirect_root_inode_operations;
+ root_inode->i_op = &autofs4_dir_inode_operations;
/* Couldn't this be tested earlier? */
if (sbi->max_proto < AUTOFS_MIN_PROTO_VERSION ||
if (inode == NULL)
return NULL;
- inf->inode = inode;
inode->i_mode = inf->mode;
if (sb->s_root) {
inode->i_uid = sb->s_root->d_inode->i_uid;
#endif
static int autofs4_dir_open(struct inode *inode, struct file *file);
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)
+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,
- .follow_link = autofs4_follow_link,
-};
-
-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() 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(&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_mountpoint(dentry)) {
- if (!autofs4_follow_mount(&nd->path)) {
- status = -ENOENT;
- 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_revalidate = autofs4_revalidate,
- .d_release = autofs4_dentry_release,
-};
-
-/* For other dentries */
-static const struct dentry_operations autofs4_dentry_operations = {
- .d_revalidate = autofs4_revalidate,
- .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 NULL;
}
+static int autofs4_mount_wait(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ int status;
+
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ DPRINTK("waiting for mount name=%.*s",
+ dentry->d_name.len, dentry->d_name.name);
+ status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+ DPRINTK("mount wait done status=%d", status);
+ ino->last_used = jiffies;
+ return status;
+ }
+ return 0;
+}
+
+static int do_expire_wait(struct dentry *dentry)
+{
+ struct dentry *expiring;
+
+ expiring = autofs4_lookup_expiring(dentry);
+ if (!expiring)
+ return autofs4_expire_wait(dentry);
+ else {
+ /*
+ * 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, just wait for it.
+ */
+ autofs4_expire_wait(expiring);
+ autofs4_del_expiring(expiring);
+ dput(expiring);
+ }
+ return 0;
+}
+
+static struct dentry *autofs4_mountpoint_changed(struct path *path)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+
+ /*
+ * If this is an indirect mount the dentry could have gone away
+ * as a result of an expire and a new one created.
+ */
+ if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
+ struct dentry *parent = dentry->d_parent;
+ struct dentry *new = d_lookup(parent, &dentry->d_name);
+ if (!new)
+ return NULL;
+ dput(path->dentry);
+ path->dentry = new;
+ }
+ return path->dentry;
+}
+
+static struct vfsmount *autofs4_d_automount(struct path *path)
+{
+ struct dentry *dentry = path->dentry;
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ int status;
+
+ DPRINTK("dentry=%p %.*s",
+ dentry, dentry->d_name.len, dentry->d_name.name);
+
+ /*
+ * Someone may have manually umounted this or it was a submount
+ * that has gone away.
+ */
+ spin_lock(&dentry->d_lock);
+ if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
+ if (!(dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
+ (dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
+ __managed_dentry_set_transit(path->dentry);
+ }
+ spin_unlock(&dentry->d_lock);
+
+ /* The daemon never triggers a mount. */
+ if (autofs4_oz_mode(sbi))
+ return NULL;
+
+ /*
+ * If an expire request is pending everyone must wait.
+ * If the expire fails we're still mounted so continue
+ * the follow and return. A return of -EAGAIN (which only
+ * happens with indirect mounts) means the expire completed
+ * and the directory was removed, so just go ahead and try
+ * the mount.
+ */
+ status = do_expire_wait(dentry);
+ if (status && status != -EAGAIN)
+ return NULL;
+
+ /* Callback to the daemon to perform the mount or wait */
+ spin_lock(&sbi->fs_lock);
+ if (ino->flags & AUTOFS_INF_PENDING) {
+ spin_unlock(&sbi->fs_lock);
+ status = autofs4_mount_wait(dentry);
+ if (status)
+ return ERR_PTR(status);
+ spin_lock(&sbi->fs_lock);
+ goto done;
+ }
+
+ /*
+ * If the dentry is a symlink it's equivalent to a directory
+ * having d_mountpoint() true, so there's no need to call back
+ * to the daemon.
+ */
+ if (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode))
+ goto done;
+ if (!d_mountpoint(dentry)) {
+ /*
+ * It's possible that user space hasn't removed directories
+ * after umounting a rootless multi-mount, although it
+ * should. For v5 have_submounts() is sufficient to handle
+ * this because the leaves of the directory tree under the
+ * mount never trigger mounts themselves (they have an autofs
+ * trigger mount mounted on them). But v4 pseudo direct mounts
+ * do need the leaves to to trigger mounts. In this case we
+ * have no choice but to use the list_empty() check and
+ * require user space behave.
+ */
+ if (sbi->version > 4) {
+ if (have_submounts(dentry))
+ goto done;
+ } else {
+ spin_lock(&dentry->d_lock);
+ if (!list_empty(&dentry->d_subdirs)) {
+ spin_unlock(&dentry->d_lock);
+ goto done;
+ }
+ spin_unlock(&dentry->d_lock);
+ }
+ ino->flags |= AUTOFS_INF_PENDING;
+ spin_unlock(&sbi->fs_lock);
+ status = autofs4_mount_wait(dentry);
+ if (status)
+ return ERR_PTR(status);
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_PENDING;
+ }
+done:
+ if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
+ /*
+ * Any needed mounting has been completed and the path updated
+ * so turn this into a normal dentry so we don't continually
+ * call ->d_automount() and ->d_manage().
+ */
+ spin_lock(&dentry->d_lock);
+ __managed_dentry_clear_transit(dentry);
+ /*
+ * Only clear DMANAGED_AUTOMOUNT for rootless multi-mounts and
+ * symlinks as in all other cases the dentry will be covered by
+ * an actual mount so ->d_automount() won't be called during
+ * the follow.
+ */
+ if ((!d_mountpoint(dentry) &&
+ !list_empty(&dentry->d_subdirs)) ||
+ (dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)))
+ __managed_dentry_clear_automount(dentry);
+ spin_unlock(&dentry->d_lock);
+ }
+ spin_unlock(&sbi->fs_lock);
+
+ /* Mount succeeded, check if we ended up with a new dentry */
+ dentry = autofs4_mountpoint_changed(path);
+ if (!dentry)
+ return ERR_PTR(-ENOENT);
+
+ return NULL;
+}
+
+int autofs4_d_manage(struct dentry *dentry, bool mounting_here, bool rcu_walk)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+
+ DPRINTK("dentry=%p %.*s",
+ dentry, dentry->d_name.len, dentry->d_name.name);
+
+ /* The daemon never waits. */
+ if (autofs4_oz_mode(sbi) || mounting_here) {
+ if (!d_mountpoint(dentry))
+ return -EISDIR;
+ 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);
+
+ /*
+ * This dentry may be under construction so wait on mount
+ * completion.
+ */
+ return autofs4_mount_wait(dentry);
+}
+
/* Lookups in the root directory */
static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
struct autofs_sb_info *sbi;
struct autofs_info *ino;
- struct dentry *expiring, *active;
- int oz_mode;
+ struct dentry *active;
- DPRINTK("name = %.*s",
- dentry->d_name.len, dentry->d_name.name);
+ DPRINTK("name = %.*s", dentry->d_name.len, dentry->d_name.name);
/* File name too long to exist */
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
sbi = autofs4_sbi(dir->i_sb);
- oz_mode = autofs4_oz_mode(sbi);
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, oz_mode);
active = autofs4_lookup_active(dentry);
if (active) {
- dentry = active;
- ino = autofs4_dentry_ino(dentry);
+ return active;
} 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.
+ * A dentry that is not within the root can never trigger a
+ * mount operation, unless the directory already exists, so we
+ * can return fail immediately. The daemon however does need
+ * to create directories within the file system.
*/
- d_set_d_op(dentry, &autofs4_root_dentry_operations);
+ if (!autofs4_oz_mode(sbi) && !IS_ROOT(dentry->d_parent))
+ return ERR_PTR(-ENOENT);
+
+ /* Mark entries in the root as mount triggers */
+ if (autofs_type_indirect(sbi->type) && IS_ROOT(dentry->d_parent))
+ __managed_dentry_set_managed(dentry);
- /*
- * 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);
d_instantiate(dentry, NULL);
}
-
- if (!oz_mode) {
- mutex_unlock(&dir->i_mutex);
- expiring = autofs4_lookup_expiring(dentry);
- if (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.
- */
- 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);
- mutex_lock(&dir->i_mutex);
- }
-
- /*
- * If we are still pending, check if we had to handle
- * a signal. If so we can force a restart..
- */
- if (ino->flags & AUTOFS_INF_PENDING) {
- /* See if we were interrupted */
- if (signal_pending(current)) {
- sigset_t *sigset = ¤t->pending.signal;
- if (sigismember (sigset, SIGKILL) ||
- sigismember (sigset, SIGQUIT) ||
- sigismember (sigset, SIGINT)) {
- if (active)
- dput(active);
- return ERR_PTR(-ERESTARTNOINTR);
- }
- }
- if (!oz_mode) {
- spin_lock(&sbi->fs_lock);
- ino->flags &= ~AUTOFS_INF_PENDING;
- spin_unlock(&sbi->fs_lock);
- }
- }
-
- /*
- * 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 (!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 (active)
- dput(active);
-
- return dentry;
- }
-
- if (active)
- return active;
-
return NULL;
}
}
d_add(dentry, inode);
- if (dir == dir->i_sb->s_root->d_inode)
- d_set_d_op(dentry, &autofs4_root_dentry_operations);
- else
- d_set_d_op(dentry, &autofs4_dentry_operations);
-
dentry->d_fsdata = ino;
ino->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;
}
+/*
+ * 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)
}
d_add(dentry, inode);
- if (dir == dir->i_sb->s_root->d_inode)
- d_set_d_op(dentry, &autofs4_root_dentry_operations);
- else
- d_set_d_op(dentry, &autofs4_dentry_operations);
+ if (sbi->version < 5)
+ autofs_set_leaf_automount_flags(dentry);
dentry->d_fsdata = ino;
ino->dentry = dget(dentry);
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;
}
* completed while we waited on the mutex ...
*/
if (notify == NFY_MOUNT) {
+ struct dentry *new = NULL;
+ int valid = 1;
+
/*
* If the dentry was successfully mounted while we slept
* on the wait queue mutex we can return success. If it
* a multi-mount with no mount at it's base) we can
* continue on and create a new request.
*/
+ if (!IS_ROOT(dentry)) {
+ if (dentry->d_inode && d_unhashed(dentry)) {
+ struct dentry *parent = dentry->d_parent;
+ new = d_lookup(parent, &dentry->d_name);
+ if (new)
+ dentry = new;
+ }
+ }
if (have_submounts(dentry))
- return 0;
+ valid = 0;
+
+ if (new)
+ dput(new);
+ return valid;
}
return 1;
}
-static int add_mount_helper(struct vfsmount *newmnt, struct nameidata *nd,
- struct list_head *mntlist)
-{
- /* stolen from afs code */
- int err;
-
- mntget(newmnt);
- err = do_add_mount(newmnt, &nd->path, nd->path.mnt->mnt_flags | MNT_SHRINKABLE, mntlist);
- switch (err) {
- case 0:
- path_put(&nd->path);
- nd->path.mnt = newmnt;
- nd->path.dentry = dget(newmnt->mnt_root);
- schedule_delayed_work(&cifs_dfs_automount_task,
- cifs_dfs_mountpoint_expiry_timeout);
- break;
- case -EBUSY:
- /* someone else made a mount here whilst we were busy */
- while (d_mountpoint(nd->path.dentry) &&
- follow_down(&nd->path))
- ;
- err = 0;
- default:
- mntput(newmnt);
- break;
- }
- return err;
-}
-
static void dump_referral(const struct dfs_info3_param *ref)
{
cFYI(1, "DFS: ref path: %s", ref->path_name);
ref->path_consumed);
}
-
-static void*
-cifs_dfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
+/*
+ * Create a vfsmount that we can automount
+ */
+static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
{
struct dfs_info3_param *referrals = NULL;
unsigned int num_referrals = 0;
struct cifs_sb_info *cifs_sb;
struct cifsSesInfo *ses;
- char *full_path = NULL;
+ char *full_path;
int xid, i;
- int rc = 0;
- struct vfsmount *mnt = ERR_PTR(-ENOENT);
+ int rc;
+ struct vfsmount *mnt;
struct tcon_link *tlink;
cFYI(1, "in %s", __func__);
- BUG_ON(IS_ROOT(dentry));
+ BUG_ON(IS_ROOT(mntpt));
xid = GetXid();
- dput(nd->path.dentry);
- nd->path.dentry = dget(dentry);
-
/*
* The MSDFS spec states that paths in DFS referral requests and
* responses must be prefixed by a single '\' character instead of
* the double backslashes usually used in the UNC. This function
* gives us the latter, so we must adjust the result.
*/
- full_path = build_path_from_dentry(dentry);
- if (full_path == NULL) {
- rc = -ENOMEM;
- goto out_err;
- }
+ mnt = ERR_PTR(-ENOMEM);
+ full_path = build_path_from_dentry(mntpt);
+ if (full_path == NULL)
+ goto free_xid;
- cifs_sb = CIFS_SB(dentry->d_inode->i_sb);
+ cifs_sb = CIFS_SB(mntpt->d_inode->i_sb);
tlink = cifs_sb_tlink(cifs_sb);
+ mnt = ERR_PTR(-EINVAL);
if (IS_ERR(tlink)) {
- rc = PTR_ERR(tlink);
- goto out_err;
+ mnt = ERR_CAST(tlink);
+ goto free_full_path;
}
ses = tlink_tcon(tlink)->ses;
cifs_put_tlink(tlink);
+ mnt = ERR_PTR(-ENOENT);
for (i = 0; i < num_referrals; i++) {
int len;
- dump_referral(referrals+i);
+ dump_referral(referrals + i);
/* connect to a node */
len = strlen(referrals[i].node_name);
if (len < 2) {
cERROR(1, "%s: Net Address path too short: %s",
__func__, referrals[i].node_name);
- rc = -EINVAL;
- goto out_err;
+ mnt = ERR_PTR(-EINVAL);
+ break;
}
mnt = cifs_dfs_do_refmount(cifs_sb,
full_path, referrals + i);
cFYI(1, "%s: cifs_dfs_do_refmount:%s , mnt:%p", __func__,
referrals[i].node_name, mnt);
-
- /* complete mount procedure if we accured submount */
if (!IS_ERR(mnt))
- break;
+ goto success;
}
- /* we need it cause for() above could exit without valid submount */
- rc = PTR_ERR(mnt);
- if (IS_ERR(mnt))
- goto out_err;
-
- rc = add_mount_helper(mnt, nd, &cifs_dfs_automount_list);
+ /* no valid submounts were found; return error from get_dfs_path() by
+ * preference */
+ if (rc != 0)
+ mnt = ERR_PTR(rc);
-out:
- FreeXid(xid);
+success:
free_dfs_info_array(referrals, num_referrals);
+free_full_path:
kfree(full_path);
+free_xid:
+ FreeXid(xid);
cFYI(1, "leaving %s" , __func__);
- return ERR_PTR(rc);
-out_err:
- path_put(&nd->path);
- goto out;
+ return mnt;
+}
+
+/*
+ * Attempt to automount the referral
+ */
+struct vfsmount *cifs_dfs_d_automount(struct path *path)
+{
+ struct vfsmount *newmnt;
+
+ cFYI(1, "in %s", __func__);
+
+ newmnt = cifs_dfs_do_automount(path->dentry);
+ if (IS_ERR(newmnt)) {
+ cFYI(1, "leaving %s [automount failed]" , __func__);
+ return newmnt;
+ }
+
+ mntget(newmnt); /* prevent immediate expiration */
+ mnt_set_expiry(newmnt, &cifs_dfs_automount_list);
+ schedule_delayed_work(&cifs_dfs_automount_task,
+ cifs_dfs_mountpoint_expiry_timeout);
+ cFYI(1, "leaving %s [ok]" , __func__);
+ return newmnt;
}
const struct inode_operations cifs_dfs_referral_inode_operations = {
- .follow_link = cifs_dfs_follow_mountpoint,
};
-
extern const struct dentry_operations cifs_dentry_ops;
extern const struct dentry_operations cifs_ci_dentry_ops;
+#ifdef CONFIG_CIFS_DFS_UPCALL
+extern struct vfsmount *cifs_dfs_d_automount(struct path *path);
+#else
+#define cifs_dfs_d_automount NULL
+#endif
+
/* Functions related to symlinks */
extern void *cifs_follow_link(struct dentry *direntry, struct nameidata *nd);
extern void cifs_put_link(struct dentry *direntry,
const struct dentry_operations cifs_dentry_ops = {
.d_revalidate = cifs_d_revalidate,
+ .d_automount = cifs_dfs_d_automount,
/* d_delete: cifs_d_delete, */ /* not needed except for debugging */
};
.d_revalidate = cifs_d_revalidate,
.d_hash = cifs_ci_hash,
.d_compare = cifs_ci_compare,
+ .d_automount = cifs_dfs_d_automount,
};
#include "fscache.h"
-static void cifs_set_ops(struct inode *inode, const bool is_dfs_referral)
+static void cifs_set_ops(struct inode *inode)
{
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
break;
case S_IFDIR:
#ifdef CONFIG_CIFS_DFS_UPCALL
- if (is_dfs_referral) {
+ if (IS_AUTOMOUNT(inode)) {
inode->i_op = &cifs_dfs_referral_inode_operations;
} else {
#else /* NO DFS support, treat as a directory */
}
spin_unlock(&inode->i_lock);
- cifs_set_ops(inode, fattr->cf_flags & CIFS_FATTR_DFS_REFERRAL);
+ if (fattr->cf_flags & CIFS_FATTR_DFS_REFERRAL)
+ inode->i_flags |= S_AUTOMOUNT;
+ cifs_set_ops(inode);
}
void
static void __d_instantiate(struct dentry *dentry, struct inode *inode)
{
spin_lock(&dentry->d_lock);
- if (inode)
+ if (inode) {
+ if (unlikely(IS_AUTOMOUNT(inode)))
+ dentry->d_flags |= DCACHE_NEED_AUTOMOUNT;
list_add(&dentry->d_alias, &inode->i_dentry);
+ }
dentry->d_inode = inode;
dentry_rcuwalk_barrier(dentry);
spin_unlock(&dentry->d_lock);
#include <linux/path.h>
#include <linux/slab.h>
#include <linux/fs_struct.h>
+#include "internal.h"
+
+static inline void path_get_longterm(struct path *path)
+{
+ path_get(path);
+ mnt_make_longterm(path->mnt);
+}
+
+static inline void path_put_longterm(struct path *path)
+{
+ mnt_make_shortterm(path->mnt);
+ path_put(path);
+}
/*
* Replace the fs->{rootmnt,root} with {mnt,dentry}. Put the old values.
write_seqcount_begin(&fs->seq);
old_root = fs->root;
fs->root = *path;
- path_get_long(path);
+ path_get_longterm(path);
write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
if (old_root.dentry)
- path_put_long(&old_root);
+ path_put_longterm(&old_root);
}
/*
write_seqcount_begin(&fs->seq);
old_pwd = fs->pwd;
fs->pwd = *path;
- path_get_long(path);
+ path_get_longterm(path);
write_seqcount_end(&fs->seq);
spin_unlock(&fs->lock);
if (old_pwd.dentry)
- path_put_long(&old_pwd);
+ path_put_longterm(&old_pwd);
}
void chroot_fs_refs(struct path *old_root, struct path *new_root)
write_seqcount_begin(&fs->seq);
if (fs->root.dentry == old_root->dentry
&& fs->root.mnt == old_root->mnt) {
- path_get_long(new_root);
+ path_get_longterm(new_root);
fs->root = *new_root;
count++;
}
if (fs->pwd.dentry == old_root->dentry
&& fs->pwd.mnt == old_root->mnt) {
- path_get_long(new_root);
+ path_get_longterm(new_root);
fs->pwd = *new_root;
count++;
}
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
while (count--)
- path_put_long(old_root);
+ path_put_longterm(old_root);
}
void free_fs_struct(struct fs_struct *fs)
{
- path_put_long(&fs->root);
- path_put_long(&fs->pwd);
+ path_put_longterm(&fs->root);
+ path_put_longterm(&fs->pwd);
kmem_cache_free(fs_cachep, fs);
}
spin_lock(&old->lock);
fs->root = old->root;
- path_get_long(&fs->root);
+ path_get_longterm(&fs->root);
fs->pwd = old->pwd;
- path_get_long(&fs->pwd);
+ path_get_longterm(&fs->pwd);
spin_unlock(&old->lock);
}
return fs;
extern void release_mounts(struct list_head *);
extern void umount_tree(struct vfsmount *, int, struct list_head *);
extern struct vfsmount *copy_tree(struct vfsmount *, struct dentry *, int);
+extern int do_add_mount(struct vfsmount *, struct path *, int);
+extern void mnt_clear_expiry(struct vfsmount *);
+
+extern void mnt_make_longterm(struct vfsmount *);
+extern void mnt_make_shortterm(struct vfsmount *);
extern void __init mnt_init(void);
}
EXPORT_SYMBOL(path_get);
-/**
- * path_get_long - get a long reference to a path
- * @path: path to get the reference to
- *
- * Given a path increment the reference count to the dentry and the vfsmount.
- */
-void path_get_long(struct path *path)
-{
- mntget_long(path->mnt);
- dget(path->dentry);
-}
-
/**
* path_put - put a reference to a path
* @path: path to put the reference to
}
EXPORT_SYMBOL(path_put);
-/**
- * path_put_long - put a long reference to a path
- * @path: path to put the reference to
- *
- * Given a path decrement the reference count to the dentry and the vfsmount.
- */
-void path_put_long(struct path *path)
-{
- dput(path->dentry);
- mntput_long(path->mnt);
-}
-
/**
* nameidata_drop_rcu - drop this nameidata out of rcu-walk
* @nd: nameidata pathwalk data to drop
touch_atime(link->mnt, dentry);
nd_set_link(nd, NULL);
- if (link->mnt != nd->path.mnt) {
- path_to_nameidata(link, nd);
- nd->inode = nd->path.dentry->d_inode;
- dget(dentry);
- }
- mntget(link->mnt);
+ if (link->mnt == nd->path.mnt)
+ mntget(link->mnt);
nd->last_type = LAST_BIND;
*p = dentry->d_inode->i_op->follow_link(dentry, nd);
}
/*
- * serialization is taken care of in namespace.c
+ * Perform an automount
+ * - return -EISDIR to tell follow_managed() to stop and return the path we
+ * were called with.
*/
-static void __follow_mount_rcu(struct nameidata *nd, struct path *path,
- struct inode **inode)
+static int follow_automount(struct path *path, unsigned flags,
+ bool *need_mntput)
{
- while (d_mountpoint(path->dentry)) {
- struct vfsmount *mounted;
- mounted = __lookup_mnt(path->mnt, path->dentry, 1);
- if (!mounted)
- return;
- path->mnt = mounted;
- path->dentry = mounted->mnt_root;
- nd->seq = read_seqcount_begin(&path->dentry->d_seq);
- *inode = path->dentry->d_inode;
+ struct vfsmount *mnt;
+ int err;
+
+ if (!path->dentry->d_op || !path->dentry->d_op->d_automount)
+ return -EREMOTE;
+
+ /* We don't want to mount if someone supplied AT_NO_AUTOMOUNT
+ * and this is the terminal part of the path.
+ */
+ if ((flags & LOOKUP_NO_AUTOMOUNT) && !(flags & LOOKUP_CONTINUE))
+ return -EISDIR; /* we actually want to stop here */
+
+ /* We want to mount if someone is trying to open/create a file of any
+ * type under the mountpoint, wants to traverse through the mountpoint
+ * or wants to open the mounted directory.
+ *
+ * We don't want to mount if someone's just doing a stat and they've
+ * set AT_SYMLINK_NOFOLLOW - unless they're stat'ing a directory and
+ * appended a '/' to the name.
+ */
+ if (!(flags & LOOKUP_FOLLOW) &&
+ !(flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY |
+ LOOKUP_OPEN | LOOKUP_CREATE)))
+ return -EISDIR;
+
+ current->total_link_count++;
+ if (current->total_link_count >= 40)
+ return -ELOOP;
+
+ mnt = path->dentry->d_op->d_automount(path);
+ if (IS_ERR(mnt)) {
+ /*
+ * The filesystem is allowed to return -EISDIR here to indicate
+ * it doesn't want to automount. For instance, autofs would do
+ * this so that its userspace daemon can mount on this dentry.
+ *
+ * However, we can only permit this if it's a terminal point in
+ * the path being looked up; if it wasn't then the remainder of
+ * the path is inaccessible and we should say so.
+ */
+ if (PTR_ERR(mnt) == -EISDIR && (flags & LOOKUP_CONTINUE))
+ return -EREMOTE;
+ return PTR_ERR(mnt);
}
-}
-static int __follow_mount(struct path *path)
-{
- int res = 0;
- while (d_mountpoint(path->dentry)) {
- struct vfsmount *mounted = lookup_mnt(path);
- if (!mounted)
- break;
+ if (!mnt) /* mount collision */
+ return 0;
+
+ /* The new mount record should have at least 2 refs to prevent it being
+ * expired before we get a chance to add it
+ */
+ BUG_ON(mnt_get_count(mnt) < 2);
+
+ if (mnt->mnt_sb == path->mnt->mnt_sb &&
+ mnt->mnt_root == path->dentry) {
+ mnt_clear_expiry(mnt);
+ mntput(mnt);
+ mntput(mnt);
+ return -ELOOP;
+ }
+
+ /* We need to add the mountpoint to the parent. The filesystem may
+ * have placed it on an expiry list, and so we need to make sure it
+ * won't be expired under us if do_add_mount() fails (do_add_mount()
+ * will eat a reference unconditionally).
+ */
+ mntget(mnt);
+ err = do_add_mount(mnt, path, path->mnt->mnt_flags | MNT_SHRINKABLE);
+ switch (err) {
+ case -EBUSY:
+ /* Someone else made a mount here whilst we were busy */
+ err = 0;
+ default:
+ mnt_clear_expiry(mnt);
+ mntput(mnt);
+ mntput(mnt);
+ return err;
+ case 0:
+ mntput(mnt);
dput(path->dentry);
- if (res)
+ if (*need_mntput)
mntput(path->mnt);
- path->mnt = mounted;
- path->dentry = dget(mounted->mnt_root);
- res = 1;
+ path->mnt = mnt;
+ path->dentry = dget(mnt->mnt_root);
+ *need_mntput = true;
+ return 0;
}
- return res;
}
-static void follow_mount(struct path *path)
+/*
+ * Handle a dentry that is managed in some way.
+ * - Flagged for transit management (autofs)
+ * - Flagged as mountpoint
+ * - Flagged as automount point
+ *
+ * This may only be called in refwalk mode.
+ *
+ * Serialization is taken care of in namespace.c
+ */
+static int follow_managed(struct path *path, unsigned flags)
{
- while (d_mountpoint(path->dentry)) {
- struct vfsmount *mounted = lookup_mnt(path);
- if (!mounted)
- break;
- dput(path->dentry);
- mntput(path->mnt);
- path->mnt = mounted;
- path->dentry = dget(mounted->mnt_root);
+ unsigned managed;
+ bool need_mntput = false;
+ int ret;
+
+ /* Given that we're not holding a lock here, we retain the value in a
+ * local variable for each dentry as we look at it so that we don't see
+ * the components of that value change under us */
+ while (managed = ACCESS_ONCE(path->dentry->d_flags),
+ managed &= DCACHE_MANAGED_DENTRY,
+ unlikely(managed != 0)) {
+ /* Allow the filesystem to manage the transit without i_mutex
+ * being held. */
+ if (managed & DCACHE_MANAGE_TRANSIT) {
+ BUG_ON(!path->dentry->d_op);
+ BUG_ON(!path->dentry->d_op->d_manage);
+ ret = path->dentry->d_op->d_manage(path->dentry,
+ false, false);
+ if (ret < 0)
+ return ret == -EISDIR ? 0 : ret;
+ }
+
+ /* Transit to a mounted filesystem. */
+ if (managed & DCACHE_MOUNTED) {
+ struct vfsmount *mounted = lookup_mnt(path);
+ if (mounted) {
+ dput(path->dentry);
+ if (need_mntput)
+ mntput(path->mnt);
+ path->mnt = mounted;
+ path->dentry = dget(mounted->mnt_root);
+ need_mntput = true;
+ continue;
+ }
+
+ /* Something is mounted on this dentry in another
+ * namespace and/or whatever was mounted there in this
+ * namespace got unmounted before we managed to get the
+ * vfsmount_lock */
+ }
+
+ /* Handle an automount point */
+ if (managed & DCACHE_NEED_AUTOMOUNT) {
+ ret = follow_automount(path, flags, &need_mntput);
+ if (ret < 0)
+ return ret == -EISDIR ? 0 : ret;
+ continue;
+ }
+
+ /* We didn't change the current path point */
+ break;
}
+ return 0;
}
-int follow_down(struct path *path)
+int follow_down_one(struct path *path)
{
struct vfsmount *mounted;
return 0;
}
+/*
+ * Skip to top of mountpoint pile in rcuwalk mode. We abort the rcu-walk if we
+ * meet a managed dentry and we're not walking to "..". True is returned to
+ * continue, false to abort.
+ */
+static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
+ struct inode **inode, bool reverse_transit)
+{
+ while (d_mountpoint(path->dentry)) {
+ struct vfsmount *mounted;
+ if (unlikely(path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
+ !reverse_transit &&
+ path->dentry->d_op->d_manage(path->dentry, false, true) < 0)
+ return false;
+ mounted = __lookup_mnt(path->mnt, path->dentry, 1);
+ if (!mounted)
+ break;
+ path->mnt = mounted;
+ path->dentry = mounted->mnt_root;
+ nd->seq = read_seqcount_begin(&path->dentry->d_seq);
+ *inode = path->dentry->d_inode;
+ }
+
+ if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
+ return reverse_transit;
+ return true;
+}
+
static int follow_dotdot_rcu(struct nameidata *nd)
{
struct inode *inode = nd->inode;
set_root_rcu(nd);
- while(1) {
+ while (1) {
if (nd->path.dentry == nd->root.dentry &&
nd->path.mnt == nd->root.mnt) {
break;
nd->seq = read_seqcount_begin(&nd->path.dentry->d_seq);
inode = nd->path.dentry->d_inode;
}
- __follow_mount_rcu(nd, &nd->path, &inode);
+ __follow_mount_rcu(nd, &nd->path, &inode, true);
nd->inode = inode;
return 0;
}
+/*
+ * Follow down to the covering mount currently visible to userspace. At each
+ * point, the filesystem owning that dentry may be queried as to whether the
+ * caller is permitted to proceed or not.
+ *
+ * Care must be taken as namespace_sem may be held (indicated by mounting_here
+ * being true).
+ */
+int follow_down(struct path *path, bool mounting_here)
+{
+ unsigned managed;
+ int ret;
+
+ while (managed = ACCESS_ONCE(path->dentry->d_flags),
+ unlikely(managed & DCACHE_MANAGED_DENTRY)) {
+ /* Allow the filesystem to manage the transit without i_mutex
+ * being held.
+ *
+ * We indicate to the filesystem if someone is trying to mount
+ * something here. This gives autofs the chance to deny anyone
+ * other than its daemon the right to mount on its
+ * superstructure.
+ *
+ * The filesystem may sleep at this point.
+ */
+ if (managed & DCACHE_MANAGE_TRANSIT) {
+ BUG_ON(!path->dentry->d_op);
+ BUG_ON(!path->dentry->d_op->d_manage);
+ ret = path->dentry->d_op->d_manage(
+ path->dentry, mounting_here, false);
+ if (ret < 0)
+ return ret == -EISDIR ? 0 : ret;
+ }
+
+ /* Transit to a mounted filesystem. */
+ if (managed & DCACHE_MOUNTED) {
+ struct vfsmount *mounted = lookup_mnt(path);
+ if (!mounted)
+ break;
+ dput(path->dentry);
+ mntput(path->mnt);
+ path->mnt = mounted;
+ path->dentry = dget(mounted->mnt_root);
+ continue;
+ }
+
+ /* Don't handle automount points here */
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Skip to top of mountpoint pile in refwalk mode for follow_dotdot()
+ */
+static void follow_mount(struct path *path)
+{
+ while (d_mountpoint(path->dentry)) {
+ struct vfsmount *mounted = lookup_mnt(path);
+ if (!mounted)
+ break;
+ dput(path->dentry);
+ mntput(path->mnt);
+ path->mnt = mounted;
+ path->dentry = dget(mounted->mnt_root);
+ }
+}
+
static void follow_dotdot(struct nameidata *nd)
{
set_root(nd);
struct vfsmount *mnt = nd->path.mnt;
struct dentry *dentry, *parent = nd->path.dentry;
struct inode *dir;
+ int err;
+
/*
* See if the low-level filesystem might want
* to use its own hash..
*/
if (unlikely(parent->d_flags & DCACHE_OP_HASH)) {
- int err = parent->d_op->d_hash(parent, nd->inode, name);
+ err = parent->d_op->d_hash(parent, nd->inode, name);
if (err < 0)
return err;
}
nd->seq = seq;
if (dentry->d_flags & DCACHE_OP_REVALIDATE)
goto need_revalidate;
+done2:
path->mnt = mnt;
path->dentry = dentry;
- __follow_mount_rcu(nd, path, inode);
- } else {
- dentry = __d_lookup(parent, name);
- if (!dentry)
- goto need_lookup;
+ if (likely(__follow_mount_rcu(nd, path, inode, false)))
+ return 0;
+ if (nameidata_drop_rcu(nd))
+ return -ECHILD;
+ /* fallthru */
+ }
+ dentry = __d_lookup(parent, name);
+ if (!dentry)
+ goto need_lookup;
found:
- if (dentry->d_flags & DCACHE_OP_REVALIDATE)
- goto need_revalidate;
+ if (dentry->d_flags & DCACHE_OP_REVALIDATE)
+ goto need_revalidate;
done:
- path->mnt = mnt;
- path->dentry = dentry;
- __follow_mount(path);
- *inode = path->dentry->d_inode;
- }
+ path->mnt = mnt;
+ path->dentry = dentry;
+ err = follow_managed(path, nd->flags);
+ if (unlikely(err < 0))
+ return err;
+ *inode = path->dentry->d_inode;
return 0;
need_lookup:
goto need_lookup;
if (IS_ERR(dentry))
goto fail;
+ if (nd->flags & LOOKUP_RCU)
+ goto done2;
goto done;
fail:
return PTR_ERR(dentry);
}
-/*
- * This is a temporary kludge to deal with "automount" symlinks; proper
- * solution is to trigger them on follow_mount(), so that do_lookup()
- * would DTRT. To be killed before 2.6.34-final.
- */
-static inline int follow_on_final(struct inode *inode, unsigned lookup_flags)
-{
- return inode && unlikely(inode->i_op->follow_link) &&
- ((lookup_flags & LOOKUP_FOLLOW) || S_ISDIR(inode->i_mode));
-}
-
/*
* Name resolution.
* This is the basic name resolution function, turning a pathname into
err = do_lookup(nd, &this, &next, &inode);
if (err)
break;
- if (follow_on_final(inode, lookup_flags)) {
+ if (inode && unlikely(inode->i_op->follow_link) &&
+ (lookup_flags & LOOKUP_FOLLOW)) {
if (nameidata_dentry_drop_rcu_maybe(nd, next.dentry))
return -ECHILD;
BUG_ON(inode != next.dentry->d_inode);
if (open_flag & O_EXCL)
goto exit_dput;
- if (__follow_mount(path)) {
- error = -ELOOP;
- if (open_flag & O_NOFOLLOW)
- goto exit_dput;
- }
+ error = follow_managed(path, nd->flags);
+ if (error < 0)
+ goto exit_dput;
error = -ENOENT;
if (!path->dentry->d_inode)
struct inode *linki = link.dentry->d_inode;
void *cookie;
error = -ELOOP;
- /* S_ISDIR part is a temporary automount kludge */
- if (!(nd.flags & LOOKUP_FOLLOW) && !S_ISDIR(linki->i_mode))
+ if (!(nd.flags & LOOKUP_FOLLOW))
goto exit_dput;
if (count++ == 32)
goto exit_dput;
};
EXPORT_SYMBOL(user_path_at);
+EXPORT_SYMBOL(follow_down_one);
EXPORT_SYMBOL(follow_down);
EXPORT_SYMBOL(follow_up);
EXPORT_SYMBOL(get_write_access); /* binfmt_aout */
unsigned int mnt_get_count(struct vfsmount *mnt)
{
#ifdef CONFIG_SMP
- unsigned int count = atomic_read(&mnt->mnt_longrefs);
+ unsigned int count = 0;
int cpu;
for_each_possible_cpu(cpu) {
if (!mnt->mnt_pcp)
goto out_free_devname;
- atomic_set(&mnt->mnt_longrefs, 1);
+ this_cpu_add(mnt->mnt_pcp->mnt_count, 1);
#else
mnt->mnt_count = 1;
mnt->mnt_writers = 0;
BUG_ON(parent == mnt);
list_add_tail(&head, &mnt->mnt_list);
- list_for_each_entry(m, &head, mnt_list)
+ list_for_each_entry(m, &head, mnt_list) {
m->mnt_ns = n;
+ atomic_inc(&m->mnt_longterm);
+ }
+
list_splice(&head, n->list.prev);
list_add_tail(&mnt->mnt_hash, mount_hashtable +
deactivate_super(sb);
}
-#ifdef CONFIG_SMP
-static inline void __mntput(struct vfsmount *mnt, int longrefs)
+static void mntput_no_expire(struct vfsmount *mnt)
{
- if (!longrefs) {
put_again:
- br_read_lock(vfsmount_lock);
- if (likely(atomic_read(&mnt->mnt_longrefs))) {
- mnt_dec_count(mnt);
- br_read_unlock(vfsmount_lock);
- return;
- }
+#ifdef CONFIG_SMP
+ br_read_lock(vfsmount_lock);
+ if (likely(atomic_read(&mnt->mnt_longterm))) {
+ mnt_dec_count(mnt);
br_read_unlock(vfsmount_lock);
- } else {
- BUG_ON(!atomic_read(&mnt->mnt_longrefs));
- if (atomic_add_unless(&mnt->mnt_longrefs, -1, 1))
- return;
+ return;
}
+ br_read_unlock(vfsmount_lock);
br_write_lock(vfsmount_lock);
- if (!longrefs)
- mnt_dec_count(mnt);
- else
- atomic_dec(&mnt->mnt_longrefs);
+ mnt_dec_count(mnt);
if (mnt_get_count(mnt)) {
br_write_unlock(vfsmount_lock);
return;
}
- if (unlikely(mnt->mnt_pinned)) {
- mnt_add_count(mnt, mnt->mnt_pinned + 1);
- mnt->mnt_pinned = 0;
- br_write_unlock(vfsmount_lock);
- acct_auto_close_mnt(mnt);
- goto put_again;
- }
- br_write_unlock(vfsmount_lock);
- mntfree(mnt);
-}
#else
-static inline void __mntput(struct vfsmount *mnt, int longrefs)
-{
-put_again:
mnt_dec_count(mnt);
if (likely(mnt_get_count(mnt)))
return;
br_write_lock(vfsmount_lock);
+#endif
if (unlikely(mnt->mnt_pinned)) {
mnt_add_count(mnt, mnt->mnt_pinned + 1);
mnt->mnt_pinned = 0;
br_write_unlock(vfsmount_lock);
mntfree(mnt);
}
-#endif
-
-static void mntput_no_expire(struct vfsmount *mnt)
-{
- __mntput(mnt, 0);
-}
void mntput(struct vfsmount *mnt)
{
/* avoid cacheline pingpong, hope gcc doesn't get "smart" */
if (unlikely(mnt->mnt_expiry_mark))
mnt->mnt_expiry_mark = 0;
- __mntput(mnt, 0);
+ mntput_no_expire(mnt);
}
}
EXPORT_SYMBOL(mntput);
}
EXPORT_SYMBOL(mntget);
-void mntput_long(struct vfsmount *mnt)
-{
-#ifdef CONFIG_SMP
- if (mnt) {
- /* avoid cacheline pingpong, hope gcc doesn't get "smart" */
- if (unlikely(mnt->mnt_expiry_mark))
- mnt->mnt_expiry_mark = 0;
- __mntput(mnt, 1);
- }
-#else
- mntput(mnt);
-#endif
-}
-EXPORT_SYMBOL(mntput_long);
-
-struct vfsmount *mntget_long(struct vfsmount *mnt)
-{
-#ifdef CONFIG_SMP
- if (mnt)
- atomic_inc(&mnt->mnt_longrefs);
- return mnt;
-#else
- return mntget(mnt);
-#endif
-}
-EXPORT_SYMBOL(mntget_long);
-
void mnt_pin(struct vfsmount *mnt)
{
br_write_lock(vfsmount_lock);
dput(dentry);
mntput(m);
}
- mntput_long(mnt);
+ mntput(mnt);
}
}
*/
void umount_tree(struct vfsmount *mnt, int propagate, struct list_head *kill)
{
+ LIST_HEAD(tmp_list);
struct vfsmount *p;
for (p = mnt; p; p = next_mnt(p, mnt))
- list_move(&p->mnt_hash, kill);
+ list_move(&p->mnt_hash, &tmp_list);
if (propagate)
- propagate_umount(kill);
+ propagate_umount(&tmp_list);
- list_for_each_entry(p, kill, mnt_hash) {
+ list_for_each_entry(p, &tmp_list, mnt_hash) {
list_del_init(&p->mnt_expire);
list_del_init(&p->mnt_list);
__touch_mnt_namespace(p->mnt_ns);
p->mnt_ns = NULL;
+ atomic_dec(&p->mnt_longterm);
list_del_init(&p->mnt_child);
if (p->mnt_parent != p) {
p->mnt_parent->mnt_ghosts++;
}
change_mnt_propagation(p, MS_PRIVATE);
}
+ list_splice(&tmp_list, kill);
}
static void shrink_submounts(struct vfsmount *mnt, struct list_head *umounts);
return err;
down_write(&namespace_sem);
- while (d_mountpoint(path->dentry) &&
- follow_down(path))
- ;
+ err = follow_down(path, true);
+ if (err < 0)
+ goto out;
+
err = -EINVAL;
if (!check_mnt(path->mnt) || !check_mnt(old_path.mnt))
goto out;
if (IS_ERR(mnt))
return PTR_ERR(mnt);
- return do_add_mount(mnt, path, mnt_flags, NULL);
+ return do_add_mount(mnt, path, mnt_flags);
}
/*
* add a mount into a namespace's mount tree
- * - provide the option of adding the new mount to an expiration list
+ * - this unconditionally eats one of the caller's references to newmnt.
*/
-int do_add_mount(struct vfsmount *newmnt, struct path *path,
- int mnt_flags, struct list_head *fslist)
+int do_add_mount(struct vfsmount *newmnt, struct path *path, int mnt_flags)
{
int err;
down_write(&namespace_sem);
/* Something was mounted here while we slept */
- while (d_mountpoint(path->dentry) &&
- follow_down(path))
- ;
+ err = follow_down(path, true);
+ if (err < 0)
+ goto unlock;
+
err = -EINVAL;
if (!(mnt_flags & MNT_SHRINKABLE) && !check_mnt(path->mnt))
goto unlock;
if ((err = graft_tree(newmnt, path)))
goto unlock;
- if (fslist) /* add to the specified expiration list */
- list_add_tail(&newmnt->mnt_expire, fslist);
-
up_write(&namespace_sem);
return 0;
unlock:
up_write(&namespace_sem);
- mntput_long(newmnt);
+ mntput(newmnt);
return err;
}
-EXPORT_SYMBOL_GPL(do_add_mount);
+/**
+ * mnt_set_expiry - Put a mount on an expiration list
+ * @mnt: The mount to list.
+ * @expiry_list: The list to add the mount to.
+ */
+void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list)
+{
+ down_write(&namespace_sem);
+ br_write_lock(vfsmount_lock);
+
+ list_add_tail(&mnt->mnt_expire, expiry_list);
+
+ br_write_unlock(vfsmount_lock);
+ up_write(&namespace_sem);
+}
+EXPORT_SYMBOL(mnt_set_expiry);
+
+/*
+ * Remove a vfsmount from any expiration list it may be on
+ */
+void mnt_clear_expiry(struct vfsmount *mnt)
+{
+ if (!list_empty(&mnt->mnt_expire)) {
+ down_write(&namespace_sem);
+ br_write_lock(vfsmount_lock);
+ list_del_init(&mnt->mnt_expire);
+ br_write_unlock(vfsmount_lock);
+ up_write(&namespace_sem);
+ }
+}
/*
* process a list of expirable mountpoints with the intent of discarding any
return new_ns;
}
+void mnt_make_longterm(struct vfsmount *mnt)
+{
+ atomic_inc(&mnt->mnt_longterm);
+}
+
+void mnt_make_shortterm(struct vfsmount *mnt)
+{
+ if (atomic_add_unless(&mnt->mnt_longterm, -1, 1))
+ return;
+ br_write_lock(vfsmount_lock);
+ atomic_dec(&mnt->mnt_longterm);
+ br_write_unlock(vfsmount_lock);
+}
+
/*
* Allocate a new namespace structure and populate it with contents
* copied from the namespace of the passed in task structure.
q = new_ns->root;
while (p) {
q->mnt_ns = new_ns;
+ atomic_inc(&q->mnt_longterm);
if (fs) {
if (p == fs->root.mnt) {
+ fs->root.mnt = mntget(q);
+ atomic_inc(&q->mnt_longterm);
+ mnt_make_shortterm(p);
rootmnt = p;
- fs->root.mnt = mntget_long(q);
}
if (p == fs->pwd.mnt) {
+ fs->pwd.mnt = mntget(q);
+ atomic_inc(&q->mnt_longterm);
+ mnt_make_shortterm(p);
pwdmnt = p;
- fs->pwd.mnt = mntget_long(q);
}
}
p = next_mnt(p, mnt_ns->root);
up_write(&namespace_sem);
if (rootmnt)
- mntput_long(rootmnt);
+ mntput(rootmnt);
if (pwdmnt)
- mntput_long(pwdmnt);
+ mntput(pwdmnt);
return new_ns;
}
new_ns = alloc_mnt_ns();
if (!IS_ERR(new_ns)) {
mnt->mnt_ns = new_ns;
+ atomic_inc(&mnt->mnt_longterm);
new_ns->root = mnt;
list_add(&new_ns->list, &new_ns->root->mnt_list);
}
{
struct nfs_server *server = NFS_SERVER(inode);
- if (test_bit(NFS_INO_MOUNTPOINT, &NFS_I(inode)->flags))
+ if (IS_AUTOMOUNT(inode))
return 0;
if (nd != NULL) {
/* VFS wants an on-the-wire revalidation */
.d_revalidate = nfs_lookup_revalidate,
.d_delete = nfs_dentry_delete,
.d_iput = nfs_dentry_iput,
+ .d_automount = nfs_d_automount,
};
static struct dentry *nfs_lookup(struct inode *dir, struct dentry * dentry, struct nameidata *nd)
.d_revalidate = nfs_open_revalidate,
.d_delete = nfs_dentry_delete,
.d_iput = nfs_dentry_iput,
+ .d_automount = nfs_d_automount,
};
/*
else
inode->i_op = &nfs_mountpoint_inode_operations;
inode->i_fop = NULL;
- set_bit(NFS_INO_MOUNTPOINT, &nfsi->flags);
+ inode->i_flags |= S_AUTOMOUNT;
}
} else if (S_ISLNK(inode->i_mode))
inode->i_op = &nfs_symlink_inode_operations;
/* Update the fsid? */
if (S_ISDIR(inode->i_mode) && (fattr->valid & NFS_ATTR_FATTR_FSID) &&
!nfs_fsid_equal(&server->fsid, &fattr->fsid) &&
- !test_bit(NFS_INO_MOUNTPOINT, &nfsi->flags))
+ !IS_AUTOMOUNT(inode))
server->fsid = fattr->fsid;
/*
const struct dentry *droot,
const struct dentry *dentry,
char *buffer, ssize_t buflen);
+extern struct vfsmount *nfs_d_automount(struct path *path);
/* getroot.c */
extern struct dentry *nfs_get_root(struct super_block *, struct nfs_fh *);
}
/*
- * nfs_follow_mountpoint - handle crossing a mountpoint on the server
- * @dentry - dentry of mountpoint
- * @nd - nameidata info
+ * nfs_d_automount - Handle crossing a mountpoint on the server
+ * @path - The mountpoint
*
* When we encounter a mountpoint on the server, we want to set up
* a mountpoint on the client too, to prevent inode numbers from
* situation, and that different filesystems may want to use
* different security flavours.
*/
-static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
+struct vfsmount *nfs_d_automount(struct path *path)
{
struct vfsmount *mnt;
- struct nfs_server *server = NFS_SERVER(dentry->d_inode);
+ struct nfs_server *server = NFS_SERVER(path->dentry->d_inode);
struct dentry *parent;
struct nfs_fh *fh = NULL;
struct nfs_fattr *fattr = NULL;
int err;
- dprintk("--> nfs_follow_mountpoint()\n");
+ dprintk("--> nfs_d_automount()\n");
- err = -ESTALE;
- if (IS_ROOT(dentry))
- goto out_err;
+ mnt = ERR_PTR(-ESTALE);
+ if (IS_ROOT(path->dentry))
+ goto out_nofree;
- err = -ENOMEM;
+ mnt = ERR_PTR(-ENOMEM);
fh = nfs_alloc_fhandle();
fattr = nfs_alloc_fattr();
if (fh == NULL || fattr == NULL)
- goto out_err;
+ goto out;
dprintk("%s: enter\n", __func__);
- dput(nd->path.dentry);
- nd->path.dentry = dget(dentry);
- /* Look it up again */
- parent = dget_parent(nd->path.dentry);
+ /* Look it up again to get its attributes */
+ parent = dget_parent(path->dentry);
err = server->nfs_client->rpc_ops->lookup(parent->d_inode,
- &nd->path.dentry->d_name,
+ &path->dentry->d_name,
fh, fattr);
dput(parent);
- if (err != 0)
- goto out_err;
+ if (err != 0) {
+ mnt = ERR_PTR(err);
+ goto out;
+ }
if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
- mnt = nfs_do_refmount(nd->path.mnt, nd->path.dentry);
+ mnt = nfs_do_refmount(path->mnt, path->dentry);
else
- mnt = nfs_do_submount(nd->path.mnt, nd->path.dentry, fh,
- fattr);
- err = PTR_ERR(mnt);
+ mnt = nfs_do_submount(path->mnt, path->dentry, fh, fattr);
if (IS_ERR(mnt))
- goto out_err;
+ goto out;
- mntget(mnt);
- err = do_add_mount(mnt, &nd->path, nd->path.mnt->mnt_flags|MNT_SHRINKABLE,
- &nfs_automount_list);
- if (err < 0) {
- mntput(mnt);
- if (err == -EBUSY)
- goto out_follow;
- goto out_err;
- }
- path_put(&nd->path);
- nd->path.mnt = mnt;
- nd->path.dentry = dget(mnt->mnt_root);
+ dprintk("%s: done, success\n", __func__);
+ mntget(mnt); /* prevent immediate expiration */
+ mnt_set_expiry(mnt, &nfs_automount_list);
schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
+
out:
nfs_free_fattr(fattr);
nfs_free_fhandle(fh);
- dprintk("%s: done, returned %d\n", __func__, err);
-
- dprintk("<-- nfs_follow_mountpoint() = %d\n", err);
- return ERR_PTR(err);
-out_err:
- path_put(&nd->path);
- goto out;
-out_follow:
- while (d_mountpoint(nd->path.dentry) &&
- follow_down(&nd->path))
- ;
- err = 0;
- goto out;
+out_nofree:
+ dprintk("<-- nfs_follow_mountpoint() = %p\n", mnt);
+ return mnt;
}
const struct inode_operations nfs_mountpoint_inode_operations = {
- .follow_link = nfs_follow_mountpoint,
.getattr = nfs_getattr,
};
const struct inode_operations nfs_referral_inode_operations = {
- .follow_link = nfs_follow_mountpoint,
};
static void nfs_expire_automounts(struct work_struct *work)
.dentry = dget(dentry)};
int err = 0;
- while (d_mountpoint(path.dentry) && follow_down(&path))
- ;
+ err = follow_down(&path, false);
+ if (err < 0)
+ goto out;
exp2 = rqst_exp_get_by_name(rqstp, &path);
if (IS_ERR(exp2)) {
static void __exit exit_pipe_fs(void)
{
unregister_filesystem(&pipe_fs_type);
- mntput_long(pipe_mnt);
+ mntput(pipe_mnt);
}
fs_initcall(init_pipe_fs);
int error = -EINVAL;
int lookup_flags = 0;
- if ((flag & ~AT_SYMLINK_NOFOLLOW) != 0)
+ if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT)) != 0)
goto out;
if (!(flag & AT_SYMLINK_NOFOLLOW))
lookup_flags |= LOOKUP_FOLLOW;
+ if (flag & AT_NO_AUTOMOUNT)
+ lookup_flags |= LOOKUP_NO_AUTOMOUNT;
error = user_path_at(dfd, filename, lookup_flags, &path);
if (error)
return mnt;
err:
- mntput_long(mnt);
+ mntput(mnt);
return ERR_PTR(err);
}
#define AUTOFS_MIN_PROTO_VERSION 3
#define AUTOFS_MAX_PROTO_VERSION 5
-#define AUTOFS_PROTO_SUBVERSION 1
+#define AUTOFS_PROTO_SUBVERSION 2
/* Mask for expire behaviour */
#define AUTOFS_EXP_IMMEDIATE 1
void (*d_release)(struct dentry *);
void (*d_iput)(struct dentry *, struct inode *);
char *(*d_dname)(struct dentry *, char *, int);
+ struct vfsmount *(*d_automount)(struct path *);
+ int (*d_manage)(struct dentry *, bool, bool);
} ____cacheline_aligned;
/*
#define DCACHE_CANT_MOUNT 0x0100
#define DCACHE_GENOCIDE 0x0200
-#define DCACHE_MOUNTED 0x0400 /* is a mountpoint */
#define DCACHE_OP_HASH 0x1000
#define DCACHE_OP_COMPARE 0x2000
#define DCACHE_OP_REVALIDATE 0x4000
#define DCACHE_OP_DELETE 0x8000
+#define DCACHE_MOUNTED 0x10000 /* is a mountpoint */
+#define DCACHE_NEED_AUTOMOUNT 0x20000 /* handle automount on this dir */
+#define DCACHE_MANAGE_TRANSIT 0x40000 /* manage transit from this dirent */
+#define DCACHE_MANAGED_DENTRY \
+ (DCACHE_MOUNTED|DCACHE_NEED_AUTOMOUNT|DCACHE_MANAGE_TRANSIT)
+
extern seqlock_t rename_lock;
static inline int dname_external(struct dentry *dentry)
extern void dput(struct dentry *);
-static inline int d_mountpoint(struct dentry *dentry)
+static inline bool d_managed(struct dentry *dentry)
+{
+ return dentry->d_flags & DCACHE_MANAGED_DENTRY;
+}
+
+static inline bool d_mountpoint(struct dentry *dentry)
{
return dentry->d_flags & DCACHE_MOUNTED;
}
#define AT_REMOVEDIR 0x200 /* Remove directory instead of
unlinking file. */
#define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
+#define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount traversal */
#ifdef __KERNEL__
#define S_SWAPFILE 256 /* Do not truncate: swapon got its bmaps */
#define S_PRIVATE 512 /* Inode is fs-internal */
#define S_IMA 1024 /* Inode has an associated IMA struct */
+#define S_AUTOMOUNT 2048 /* Automount/referral quasi-directory */
/*
* Note that nosuid etc flags are inode-specific: setting some file-system
#define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE)
#define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE)
#define IS_IMA(inode) ((inode)->i_flags & S_IMA)
+#define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT)
/* the read-only stuff doesn't really belong here, but any other place is
probably as bad and I don't want to create yet another include file. */
struct super_block *mnt_sb; /* pointer to superblock */
#ifdef CONFIG_SMP
struct mnt_pcp __percpu *mnt_pcp;
- atomic_t mnt_longrefs;
+ atomic_t mnt_longterm; /* how many of the refs are longterm */
#else
int mnt_count;
int mnt_writers;
extern void mnt_drop_write(struct vfsmount *mnt);
extern void mntput(struct vfsmount *mnt);
extern struct vfsmount *mntget(struct vfsmount *mnt);
-extern void mntput_long(struct vfsmount *mnt);
-extern struct vfsmount *mntget_long(struct vfsmount *mnt);
extern void mnt_pin(struct vfsmount *mnt);
extern void mnt_unpin(struct vfsmount *mnt);
extern int __mnt_is_readonly(struct vfsmount *mnt);
int flags, const char *name,
void *data);
-struct nameidata;
-
-struct path;
-extern int do_add_mount(struct vfsmount *newmnt, struct path *path,
- int mnt_flags, struct list_head *fslist);
-
+extern void mnt_set_expiry(struct vfsmount *mnt, struct list_head *expiry_list);
extern void mark_mounts_for_expiry(struct list_head *mounts);
extern dev_t name_to_dev_t(char *name);
* - ending slashes ok even for nonexistent files
* - internal "there are more path components" flag
* - dentry cache is untrusted; force a real lookup
+ * - suppress terminal automount
*/
#define LOOKUP_FOLLOW 0x0001
#define LOOKUP_DIRECTORY 0x0002
#define LOOKUP_PARENT 0x0010
#define LOOKUP_REVAL 0x0020
#define LOOKUP_RCU 0x0040
+#define LOOKUP_NO_AUTOMOUNT 0x0080
/*
* Intent data
*/
extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
-extern int follow_down(struct path *);
+extern int follow_down_one(struct path *);
+extern int follow_down(struct path *, bool);
extern int follow_up(struct path *);
extern struct dentry *lock_rename(struct dentry *, struct dentry *);
#define NFS_INO_ADVISE_RDPLUS (0) /* advise readdirplus */
#define NFS_INO_STALE (1) /* possible stale inode */
#define NFS_INO_ACL_LRU_SET (2) /* Inode is on the LRU list */
-#define NFS_INO_MOUNTPOINT (3) /* inode is remote mountpoint */
#define NFS_INO_FLUSHING (4) /* inode is flushing out data */
#define NFS_INO_FSCACHE (5) /* inode can be cached by FS-Cache */
#define NFS_INO_FSCACHE_LOCK (6) /* FS-Cache cookie management lock */
};
extern void path_get(struct path *);
-extern void path_get_long(struct path *);
extern void path_put(struct path *);
-extern void path_put_long(struct path *);
static inline int path_equal(const struct path *path1, const struct path *path2)
{
projects / firefly-linux-kernel-4.4.55.git / commitdiff