diff options
Diffstat (limited to 'fs/autofs4')
| -rw-r--r-- | fs/autofs4/autofs_i.h | 99 | ||||
| -rw-r--r-- | fs/autofs4/dev-ioctl.c | 2 | ||||
| -rw-r--r-- | fs/autofs4/expire.c | 51 | ||||
| -rw-r--r-- | fs/autofs4/inode.c | 26 | ||||
| -rw-r--r-- | fs/autofs4/root.c | 673 | ||||
| -rw-r--r-- | fs/autofs4/waitq.c | 17 |
6 files changed, 408 insertions, 460 deletions
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index 0fffe1c24cec..1f016bfb42d5 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -99,7 +99,6 @@ struct autofs_info { }; #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 { @@ -176,13 +175,6 @@ static inline int autofs4_ispending(struct dentry *dentry) 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 *); @@ -212,11 +204,83 @@ void autofs_dev_ioctl_exit(void); 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 */ @@ -229,19 +293,6 @@ int autofs4_wait(struct autofs_sb_info *,struct dentry *, enum autofs_notify); 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); diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index eff9a419469a..1442da4860e5 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -551,7 +551,7 @@ static int autofs_dev_ioctl_ismountpoint(struct file *fp, err = have_submounts(path.dentry); - if (follow_down(&path)) + if (follow_down_one(&path)) magic = path.mnt->mnt_sb->s_magic; } diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c index cc1d01365905..3ed79d76c233 100644 --- a/fs/autofs4/expire.c +++ b/fs/autofs4/expire.c @@ -26,10 +26,6 @@ static inline int autofs4_can_expire(struct dentry *dentry, 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)) @@ -56,7 +52,7 @@ static int autofs4_mount_busy(struct vfsmount *mnt, struct dentry *dentry) path_get(&path); - if (!follow_down(&path)) + if (!follow_down_one(&path)) goto done; if (is_autofs4_dentry(path.dentry)) { @@ -283,6 +279,7 @@ struct dentry *autofs4_expire_direct(struct super_block *sb, 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; @@ -291,19 +288,21 @@ struct dentry *autofs4_expire_direct(struct super_block *sb, 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); @@ -340,6 +339,10 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, 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 @@ -399,6 +402,8 @@ struct dentry *autofs4_expire_indirect(struct super_block *sb, } } next: + managed_dentry_clear_transit(dentry); +cont: spin_unlock(&sbi->fs_lock); } return NULL; @@ -479,6 +484,8 @@ int autofs4_expire_run(struct super_block *sb, 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); @@ -504,18 +511,18 @@ int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt, 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); diff --git a/fs/autofs4/inode.c b/fs/autofs4/inode.c index a7bdb9dcac84..9e1a9dad23e1 100644 --- a/fs/autofs4/inode.c +++ b/fs/autofs4/inode.c @@ -45,7 +45,6 @@ struct autofs_info *autofs4_init_ino(struct autofs_info *ino, if (!reinit) { ino->flags = 0; - ino->inode = NULL; ino->dentry = NULL; ino->size = 0; INIT_LIST_HEAD(&ino->active); @@ -76,19 +75,8 @@ struct autofs_info *autofs4_init_ino(struct autofs_info *ino, 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) @@ -251,10 +239,6 @@ static struct autofs_info *autofs4_mkroot(struct autofs_sb_info *sbi) 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; @@ -292,6 +276,7 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) 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; /* @@ -309,7 +294,6 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) goto fail_iput; pipe = NULL; - d_set_d_op(root, &autofs4_sb_dentry_operations); root->d_fsdata = ino; /* Can this call block? */ @@ -320,10 +304,11 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent) 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 || @@ -391,7 +376,6 @@ struct inode *autofs4_get_inode(struct super_block *sb, 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; diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c index 651e4ef563b1..1dba035fc376 100644 --- a/fs/autofs4/root.c +++ b/fs/autofs4/root.c @@ -35,10 +35,8 @@ static long autofs4_root_compat_ioctl(struct file *,unsigned int,unsigned long); #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, @@ -60,7 +58,7 @@ const struct file_operations autofs4_dir_operations = { .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, @@ -68,20 +66,10 @@ const struct inode_operations autofs4_indirect_root_inode_operations = { .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) @@ -116,14 +104,6 @@ static void autofs4_del_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; @@ -158,239 +138,6 @@ out: 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; @@ -398,11 +145,8 @@ void autofs4_dentry_release(struct dentry *de) 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)) @@ -411,26 +155,10 @@ void autofs4_dentry_release(struct dentry *de) 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); @@ -541,50 +269,244 @@ next: 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); @@ -596,82 +518,6 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s 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; } @@ -716,18 +562,12 @@ static int autofs4_dir_symlink(struct inode *dir, } 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; @@ -782,6 +622,58 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) 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); @@ -809,6 +701,9 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry) 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) @@ -851,10 +746,8 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) } 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); @@ -862,7 +755,6 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) 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; @@ -944,8 +836,7 @@ static inline int autofs4_ask_umount(struct vfsmount *mnt, int __user *p) 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; } diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index c5f8459c905e..56010056b2e6 100644 --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -309,6 +309,9 @@ static int validate_request(struct autofs_wait_queue **wait, * 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 @@ -316,8 +319,20 @@ static int validate_request(struct autofs_wait_queue **wait, * 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; |