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-rw-r--r--fs/autofs4/autofs_i.h38
-rw-r--r--fs/autofs4/expire.c8
-rw-r--r--fs/autofs4/inode.c2
-rw-r--r--fs/autofs4/root.c616
4 files changed, 449 insertions, 215 deletions
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 8f7cdde4173..0118d67221b 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -60,6 +60,11 @@ do { \
current->pid, __func__, ##args); \
} while (0)
+struct rehash_entry {
+ struct task_struct *task;
+ struct list_head list;
+};
+
/* Unified info structure. This is pointed to by both the dentry and
inode structures. Each file in the filesystem has an instance of this
structure. It holds a reference to the dentry, so dentries are never
@@ -75,6 +80,9 @@ struct autofs_info {
struct completion expire_complete;
struct list_head active;
+ int active_count;
+ struct list_head rehash_list;
+
struct list_head expiring;
struct autofs_sb_info *sbi;
@@ -95,6 +103,8 @@ 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 */
+#define AUTOFS_INF_REHASH (1<<3) /* dentry in transit to ->lookup() */
struct autofs_wait_queue {
wait_queue_head_t queue;
@@ -161,7 +171,7 @@ static inline int autofs4_ispending(struct dentry *dentry)
{
struct autofs_info *inf = autofs4_dentry_ino(dentry);
- if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
+ if (inf->flags & AUTOFS_INF_PENDING)
return 1;
if (inf->flags & AUTOFS_INF_EXPIRING)
@@ -264,5 +274,31 @@ out:
return ret;
}
+static inline void autofs4_add_expiring(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino) {
+ spin_lock(&sbi->lookup_lock);
+ if (list_empty(&ino->expiring))
+ list_add(&ino->expiring, &sbi->expiring_list);
+ spin_unlock(&sbi->lookup_lock);
+ }
+ return;
+}
+
+static inline void autofs4_del_expiring(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino) {
+ spin_lock(&sbi->lookup_lock);
+ if (!list_empty(&ino->expiring))
+ list_del_init(&ino->expiring);
+ spin_unlock(&sbi->lookup_lock);
+ }
+ return;
+}
+
void autofs4_dentry_release(struct dentry *);
extern void autofs4_kill_sb(struct super_block *);
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index 3da18d45348..74bc9aa6df3 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -27,7 +27,7 @@ static inline int autofs4_can_expire(struct dentry *dentry,
return 0;
/* No point expiring a pending mount */
- if (dentry->d_flags & DCACHE_AUTOFS_PENDING)
+ if (ino->flags & AUTOFS_INF_PENDING)
return 0;
if (!do_now) {
@@ -279,6 +279,7 @@ struct dentry *autofs4_expire_direct(struct super_block *sb,
root->d_mounted--;
}
ino->flags |= AUTOFS_INF_EXPIRING;
+ autofs4_add_expiring(root);
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
return root;
@@ -406,6 +407,7 @@ found:
expired, (int)expired->d_name.len, expired->d_name.name);
ino = autofs4_dentry_ino(expired);
ino->flags |= AUTOFS_INF_EXPIRING;
+ autofs4_add_expiring(expired);
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
spin_lock(&dcache_lock);
@@ -433,7 +435,7 @@ int autofs4_expire_wait(struct dentry *dentry)
DPRINTK("expire done status=%d", status);
- if (d_unhashed(dentry))
+ if (d_unhashed(dentry) && IS_DEADDIR(dentry->d_inode))
return -EAGAIN;
return status;
@@ -473,6 +475,7 @@ int autofs4_expire_run(struct super_block *sb,
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
ino->flags &= ~AUTOFS_INF_EXPIRING;
+ autofs4_del_expiring(dentry);
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
@@ -503,6 +506,7 @@ int autofs4_do_expire_multi(struct super_block *sb, struct vfsmount *mnt,
ino->flags &= ~AUTOFS_INF_MOUNTPOINT;
}
ino->flags &= ~AUTOFS_INF_EXPIRING;
+ autofs4_del_expiring(dentry);
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 69c8142da83..d0a3de24745 100644
--- a/fs/autofs4/inode.c
+++ b/fs/autofs4/inode.c
@@ -49,6 +49,8 @@ struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
ino->dentry = NULL;
ino->size = 0;
INIT_LIST_HEAD(&ino->active);
+ INIT_LIST_HEAD(&ino->rehash_list);
+ ino->active_count = 0;
INIT_LIST_HEAD(&ino->expiring);
atomic_set(&ino->count, 0);
}
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index b96a3c57359..30cc9ddf4b7 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -72,6 +72,139 @@ const struct inode_operations autofs4_dir_inode_operations = {
.rmdir = autofs4_dir_rmdir,
};
+static void autofs4_add_active(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino) {
+ spin_lock(&sbi->lookup_lock);
+ if (!ino->active_count) {
+ if (list_empty(&ino->active))
+ list_add(&ino->active, &sbi->active_list);
+ }
+ ino->active_count++;
+ spin_unlock(&sbi->lookup_lock);
+ }
+ return;
+}
+
+static void autofs4_del_active(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino) {
+ spin_lock(&sbi->lookup_lock);
+ ino->active_count--;
+ if (!ino->active_count) {
+ if (!list_empty(&ino->active))
+ list_del_init(&ino->active);
+ }
+ spin_unlock(&sbi->lookup_lock);
+ }
+ return;
+}
+
+static void autofs4_add_rehash_entry(struct autofs_info *ino,
+ struct rehash_entry *entry)
+{
+ entry->task = current;
+ INIT_LIST_HEAD(&entry->list);
+ list_add(&entry->list, &ino->rehash_list);
+ return;
+}
+
+static void autofs4_remove_rehash_entry(struct autofs_info *ino)
+{
+ struct list_head *head = &ino->rehash_list;
+ struct rehash_entry *entry;
+ list_for_each_entry(entry, head, list) {
+ if (entry->task == current) {
+ list_del(&entry->list);
+ kfree(entry);
+ break;
+ }
+ }
+ return;
+}
+
+static void autofs4_remove_rehash_entrys(struct autofs_info *ino)
+{
+ struct autofs_sb_info *sbi = ino->sbi;
+ struct rehash_entry *entry, *next;
+ struct list_head *head;
+
+ spin_lock(&sbi->fs_lock);
+ spin_lock(&sbi->lookup_lock);
+ if (!(ino->flags & AUTOFS_INF_REHASH)) {
+ spin_unlock(&sbi->lookup_lock);
+ spin_unlock(&sbi->fs_lock);
+ return;
+ }
+ ino->flags &= ~AUTOFS_INF_REHASH;
+ head = &ino->rehash_list;
+ list_for_each_entry_safe(entry, next, head, list) {
+ list_del(&entry->list);
+ kfree(entry);
+ }
+ spin_unlock(&sbi->lookup_lock);
+ spin_unlock(&sbi->fs_lock);
+ dput(ino->dentry);
+
+ return;
+}
+
+static void autofs4_revalidate_drop(struct dentry *dentry,
+ struct rehash_entry *entry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ /*
+ * Add to the active list so we can pick this up in
+ * ->lookup(). Also add an entry to a rehash list so
+ * we know when there are no dentrys in flight so we
+ * know when we can rehash the dentry.
+ */
+ spin_lock(&sbi->lookup_lock);
+ if (list_empty(&ino->active))
+ list_add(&ino->active, &sbi->active_list);
+ autofs4_add_rehash_entry(ino, entry);
+ spin_unlock(&sbi->lookup_lock);
+ if (!(ino->flags & AUTOFS_INF_REHASH)) {
+ ino->flags |= AUTOFS_INF_REHASH;
+ dget(dentry);
+ spin_lock(&dentry->d_lock);
+ __d_drop(dentry);
+ spin_unlock(&dentry->d_lock);
+ }
+ return;
+}
+
+static void autofs4_revalidate_rehash(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ if (ino->flags & AUTOFS_INF_REHASH) {
+ spin_lock(&sbi->lookup_lock);
+ autofs4_remove_rehash_entry(ino);
+ if (list_empty(&ino->rehash_list)) {
+ spin_unlock(&sbi->lookup_lock);
+ ino->flags &= ~AUTOFS_INF_REHASH;
+ d_rehash(dentry);
+ dput(ino->dentry);
+ } else
+ spin_unlock(&sbi->lookup_lock);
+ }
+ 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;
@@ -93,7 +226,7 @@ static int autofs4_dir_open(struct inode *inode, struct file *file)
* it.
*/
spin_lock(&dcache_lock);
- if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
+ if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
spin_unlock(&dcache_lock);
return -ENOENT;
}
@@ -103,7 +236,7 @@ out:
return dcache_dir_open(inode, file);
}
-static int try_to_fill_dentry(struct dentry *dentry, int flags)
+static int try_to_fill_dentry(struct dentry *dentry)
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
@@ -116,55 +249,17 @@ static int try_to_fill_dentry(struct dentry *dentry, int flags)
* 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(&dentry->d_lock);
- dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
- spin_unlock(&dentry->d_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 (dentry->d_flags & DCACHE_AUTOFS_PENDING ||
- flags & (TRIGGER_FLAGS | TRIGGER_INTENTS) ||
- current->link_count) {
- DPRINTK("waiting for mount name=%.*s",
- dentry->d_name.len, dentry->d_name.name);
-
- spin_lock(&dentry->d_lock);
- dentry->d_flags |= DCACHE_AUTOFS_PENDING;
- spin_unlock(&dentry->d_lock);
- status = autofs4_wait(sbi, dentry, NFY_MOUNT);
+ DPRINTK("waiting for mount name=%.*s",
+ dentry->d_name.len, dentry->d_name.name);
- DPRINTK("mount done status=%d", status);
+ status = autofs4_wait(sbi, dentry, NFY_MOUNT);
- if (status) {
- spin_lock(&dentry->d_lock);
- dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
- spin_unlock(&dentry->d_lock);
- return status;
- }
- }
-
- /* Initialize expiry counter after successful mount */
- if (ino)
- ino->last_used = jiffies;
+ DPRINTK("mount done status=%d", status);
- spin_lock(&dentry->d_lock);
- dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
- spin_unlock(&dentry->d_lock);
+ /* Update expiry counter */
+ ino->last_used = jiffies;
- return 0;
+ return status;
}
/* For autofs direct mounts the follow link triggers the mount */
@@ -202,27 +297,39 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
autofs4_expire_wait(dentry);
/* We trigger a mount for almost all flags */
- lookup_type = nd->flags & (TRIGGER_FLAGS | TRIGGER_INTENTS);
- if (!(lookup_type || dentry->d_flags & DCACHE_AUTOFS_PENDING))
+ lookup_type = autofs4_need_mount(nd->flags);
+ spin_lock(&sbi->fs_lock);
+ spin_lock(&dcache_lock);
+ if (!(lookup_type || ino->flags & AUTOFS_INF_PENDING)) {
+ spin_unlock(&dcache_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.
*/
- spin_lock(&dcache_lock);
- if (dentry->d_flags & DCACHE_AUTOFS_PENDING ||
- (!d_mountpoint(dentry) && __simple_empty(dentry))) {
+ if (ino->flags & AUTOFS_INF_PENDING ||
+ (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
+ ino->flags |= AUTOFS_INF_PENDING;
spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
+
+ status = try_to_fill_dentry(dentry);
+
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_PENDING;
+ spin_unlock(&sbi->fs_lock);
- status = try_to_fill_dentry(dentry, 0);
if (status)
goto out_error;
goto follow;
}
spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
follow:
/*
* If there is no root mount it must be an autofs
@@ -254,18 +361,47 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
{
struct inode *dir = dentry->d_parent->d_inode;
struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb);
- int oz_mode = autofs4_oz_mode(sbi);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ struct rehash_entry *entry;
int flags = nd ? nd->flags : 0;
- int status = 1;
+ unsigned int mutex_aquired;
+
+ DPRINTK("name = %.*s oz_mode = %d",
+ dentry->d_name.len, dentry->d_name.name, oz_mode);
+
+ /* Daemon never causes a mount to trigger */
+ if (autofs4_oz_mode(sbi))
+ return 1;
+
+ entry = kmalloc(sizeof(struct rehash_entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ mutex_aquired = mutex_trylock(&dir->i_mutex);
- /* Pending dentry */
spin_lock(&sbi->fs_lock);
+ spin_lock(&dcache_lock);
+ /* Pending dentry */
if (autofs4_ispending(dentry)) {
- /* The daemon never causes a mount to trigger */
- spin_unlock(&sbi->fs_lock);
+ int status;
- if (oz_mode)
- return 1;
+ /*
+ * We can only unhash and send this to ->lookup() if
+ * the directory mutex is held over d_revalidate() and
+ * ->lookup(). This prevents the VFS from incorrectly
+ * seeing the dentry as non-existent.
+ */
+ ino->flags |= AUTOFS_INF_PENDING;
+ if (!mutex_aquired) {
+ autofs4_revalidate_drop(dentry, entry);
+ spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
+ return 0;
+ }
+ spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
+ mutex_unlock(&dir->i_mutex);
+ kfree(entry);
/*
* If the directory has gone away due to an expire
@@ -279,46 +415,82 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
* A zero status is success otherwise we have a
* negative error code.
*/
- status = try_to_fill_dentry(dentry, flags);
+ status = try_to_fill_dentry(dentry);
+
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_PENDING;
+ spin_unlock(&sbi->fs_lock);
+
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(&dcache_lock);
if (S_ISDIR(dentry->d_inode->i_mode) &&
- !d_mountpoint(dentry) &&
- __simple_empty(dentry)) {
+ !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
DPRINTK("dentry=%p %.*s, emptydir",
dentry, dentry->d_name.len, dentry->d_name.name);
- spin_unlock(&dcache_lock);
- /* The daemon never causes a mount to trigger */
- if (oz_mode)
- return 1;
+ if (autofs4_need_mount(flags) || current->link_count) {
+ int status;
- /*
- * A zero status is success otherwise we have a
- * negative error code.
- */
- status = try_to_fill_dentry(dentry, flags);
- if (status == 0)
- return 1;
+ /*
+ * We can only unhash and send this to ->lookup() if
+ * the directory mutex is held over d_revalidate() and
+ * ->lookup(). This prevents the VFS from incorrectly
+ * seeing the dentry as non-existent.
+ */
+ ino->flags |= AUTOFS_INF_PENDING;
+ if (!mutex_aquired) {
+ autofs4_revalidate_drop(dentry, entry);
+ spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
+ return 0;
+ }
+ spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
+ mutex_unlock(&dir->i_mutex);
+ kfree(entry);
- return status;
+ /*
+ * A zero status is success otherwise we have a
+ * negative error code.
+ */
+ status = try_to_fill_dentry(dentry);
+
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_PENDING;
+ spin_unlock(&sbi->fs_lock);
+
+ if (status == 0)
+ return 1;
+
+ return status;
+ }
}
spin_unlock(&dcache_lock);
+ spin_unlock(&sbi->fs_lock);
+
+ if (mutex_aquired)
+ mutex_unlock(&dir->i_mutex);
+
+ kfree(entry);
return 1;
}
+static void autofs4_free_rehash_entrys(struct autofs_info *inf)
+{
+ struct list_head *head = &inf->rehash_list;
+ struct rehash_entry *entry, *next;
+ list_for_each_entry_safe(entry, next, head, list) {
+ list_del(&entry->list);
+ kfree(entry);
+ }
+}
+
void autofs4_dentry_release(struct dentry *de)
{
struct autofs_info *inf;
@@ -337,6 +509,8 @@ void autofs4_dentry_release(struct dentry *de)
list_del(&inf->active);
if (!list_empty(&inf->expiring))
list_del(&inf->expiring);
+ if (!list_empty(&inf->rehash_list))
+ autofs4_free_rehash_entrys(inf);
spin_unlock(&sbi->lookup_lock);
}
@@ -359,35 +533,52 @@ static const struct dentry_operations autofs4_dentry_operations = {
.d_release = autofs4_dentry_release,
};
-static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
+static struct dentry *autofs4_lookup_active(struct dentry *dentry)
{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct dentry *parent = dentry->d_parent;
+ struct qstr *name = &dentry->d_name;
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
struct list_head *p, *head;
+restart:
spin_lock(&dcache_lock);
spin_lock(&sbi->lookup_lock);
head = &sbi->active_list;
list_for_each(p, head) {
struct autofs_info *ino;
- struct dentry *dentry;
+ struct dentry *active;
struct qstr *qstr;
ino = list_entry(p, struct autofs_info, active);
- dentry = ino->dentry;
+ active = ino->dentry;
- spin_lock(&dentry->d_lock);
+ spin_lock(&active->d_lock);
/* Already gone? */
- if (atomic_read(&dentry->d_count) == 0)
+ if (atomic_read(&active->d_count) == 0)
goto next;
- qstr = &dentry->d_name;
+ if (active->d_inode && IS_DEADDIR(active->d_inode)) {
+ if (!list_empty(&ino->rehash_list)) {
+ dget(active);
+ spin_unlock(&active->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ spin_unlock(&dcache_lock);
+ autofs4_remove_rehash_entrys(ino);
+ dput(active);
+ goto restart;
+ }
+ goto next;
+ }
+
+ qstr = &active->d_name;
- if (dentry->d_name.hash != hash)
+ if (active->d_name.hash != hash)
goto next;
- if (dentry->d_parent != parent)
+ if (active->d_parent != parent)
goto next;
if (qstr->len != len)
@@ -395,15 +586,13 @@ static struct dentry *autofs4_lookup_active(struct autofs_sb_info *sbi, struct d
if (memcmp(qstr->name, str, len))
goto next;
- if (d_unhashed(dentry)) {
- dget(dentry);
- spin_unlock(&dentry->d_lock);
- spin_unlock(&sbi->lookup_lock);
- spin_unlock(&dcache_lock);
- return dentry;
- }
+ dget(active);
+ spin_unlock(&active->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ spin_unlock(&dcache_lock);
+ return active;
next:
- spin_unlock(&dentry->d_lock);
+ spin_unlock(&active->d_lock);
}
spin_unlock(&sbi->lookup_lock);
spin_unlock(&dcache_lock);
@@ -411,8 +600,11 @@ next:
return NULL;
}
-static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
+static struct dentry *autofs4_lookup_expiring(struct dentry *dentry)
{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct dentry *parent = dentry->d_parent;
+ struct qstr *name = &dentry->d_name;
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
@@ -423,23 +615,23 @@ static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct
head = &sbi->expiring_list;
list_for_each(p, head) {
struct autofs_info *ino;
- struct dentry *dentry;
+ struct dentry *expiring;
struct qstr *qstr;
ino = list_entry(p, struct autofs_info, expiring);
- dentry = ino->dentry;
+ expiring = ino->dentry;
- spin_lock(&dentry->d_lock);
+ spin_lock(&expiring->d_lock);
/* Bad luck, we've already been dentry_iput */
- if (!dentry->d_inode)
+ if (!expiring->d_inode)
goto next;
- qstr = &dentry->d_name;
+ qstr = &expiring->d_name;
- if (dentry->d_name.hash != hash)
+ if (expiring->d_name.hash != hash)
goto next;
- if (dentry->d_parent != parent)
+ if (expiring->d_parent != parent)
goto next;
if (qstr->len != len)
@@ -447,15 +639,13 @@ static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct
if (memcmp(qstr->name, str, len))
goto next;
- if (d_unhashed(dentry)) {
- dget(dentry);
- spin_unlock(&dentry->d_lock);
- spin_unlock(&sbi->lookup_lock);
- spin_unlock(&dcache_lock);
- return dentry;
- }
+ dget(expiring);
+ spin_unlock(&expiring->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ spin_unlock(&dcache_lock);
+ return expiring;
next:
- spin_unlock(&dentry->d_lock);
+ spin_unlock(&expiring->d_lock);
}
spin_unlock(&sbi->lookup_lock);
spin_unlock(&dcache_lock);
@@ -463,13 +653,56 @@ next:
return NULL;
}
+static struct autofs_info *init_new_dentry(struct autofs_sb_info *sbi,
+ struct dentry *dentry, int oz_mode)
+{
+ struct autofs_info *ino;
+
+ /*
+ * Mark the dentry incomplete but don't hash it. We do this
+ * to serialize our inode creation operations (symlink and
+ * mkdir) which prevents deadlock during the callback to
+ * the daemon. Subsequent user space lookups for the same
+ * dentry are placed on the wait queue while the daemon
+ * itself is allowed passage unresticted so the create
+ * operation itself can then hash the dentry. Finally,
+ * we check for the hashed dentry and return the newly
+ * hashed dentry.
+ */
+ dentry->d_op = &autofs4_root_dentry_operations;
+
+ /*
+ * And we need to ensure that the same dentry is used for
+ * all following lookup calls until it is hashed so that
+ * the dentry flags are persistent throughout the request.
+ */
+ ino = autofs4_init_ino(NULL, sbi, 0555);
+ if (!ino)
+ return ERR_PTR(-ENOMEM);
+
+ dentry->d_fsdata = ino;
+ ino->dentry = dentry;
+
+ /*
+ * Only set the mount pending flag for new dentrys not created
+ * by the daemon.
+ */
+ if (!oz_mode)
+ ino->flags |= AUTOFS_INF_PENDING;
+
+ d_instantiate(dentry, NULL);
+
+ return ino;
+}
+
/* Lookups in the root directory */
static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
struct autofs_sb_info *sbi;
struct autofs_info *ino;
- struct dentry *expiring, *unhashed;
+ struct dentry *expiring, *active;
int oz_mode;
+ int status = 0;
DPRINTK("name = %.*s",
dentry->d_name.len, dentry->d_name.name);
@@ -484,123 +717,100 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
DPRINTK("pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d",
current->pid, task_pgrp_nr(current), sbi->catatonic, oz_mode);
- unhashed = autofs4_lookup_active(sbi, dentry->d_parent, &dentry->d_name);
- if (unhashed)
- dentry = unhashed;
- else {
- /*
- * Mark the dentry incomplete but don't hash it. We do this
- * to serialize our inode creation operations (symlink and
- * mkdir) which prevents deadlock during the callback to
- * the daemon. Subsequent user space lookups for the same
- * dentry are placed on the wait queue while the daemon
- * itself is allowed passage unresticted so the create
- * operation itself can then hash the dentry. Finally,
- * we check for the hashed dentry and return the newly
- * hashed dentry.
- */
- dentry->d_op = &autofs4_root_dentry_operations;
-
- /*
- * And we need to ensure that the same dentry is used for
- * all following lookup calls until it is hashed so that
- * the dentry flags are persistent throughout the request.
- */
- ino = autofs4_init_ino(NULL, sbi, 0555);
- if (!ino)
- return ERR_PTR(-ENOMEM);
-
- dentry->d_fsdata = ino;
- ino->dentry = dentry;
-
- spin_lock(&sbi->lookup_lock);
- list_add(&ino->active, &sbi->active_list);
- spin_unlock(&sbi->lookup_lock);
-
- d_instantiate(dentry, NULL);
+ spin_lock(&sbi->fs_lock);
+ active = autofs4_lookup_active(dentry);
+ if (active) {
+ dentry = active;
+ ino = autofs4_dentry_ino(dentry);
+ /* If this came from revalidate, rehash it */
+ autofs4_revalidate_rehash(dentry);
+ spin_unlock(&sbi->fs_lock);
+ } else {
+ spin_unlock(&sbi->fs_lock);
+ ino = init_new_dentry(sbi, dentry, oz_mode);
+ if (IS_ERR(ino))
+ return (struct dentry *) ino;
}
+ autofs4_add_active(dentry);
+
if (!oz_mode) {
+ expiring = autofs4_lookup_expiring(dentry);
mutex_unlock(&dir->i_mutex);
- expiring = autofs4_lookup_expiring(sbi,
- dentry->d_parent,
- &dentry->d_name);
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.
*/
- ino = autofs4_dentry_ino(expiring);
autofs4_expire_wait(expiring);
- spin_lock(&sbi->lookup_lock);
- if (!list_empty(&ino->expiring))
- list_del_init(&ino->expiring);
- spin_unlock(&sbi->lookup_lock);
dput(expiring);
}
-
- spin_lock(&dentry->d_lock);
- dentry->d_flags |= DCACHE_AUTOFS_PENDING;
- spin_unlock(&dentry->d_lock);
- if (dentry->d_op && dentry->d_op->d_revalidate)
- (dentry->d_op->d_revalidate)(dentry, nd);
+ status = try_to_fill_dentry(dentry);
mutex_lock(&dir->i_mutex);
+ spin_lock(&sbi->fs_lock);
+ ino->flags &= ~AUTOFS_INF_PENDING;
+ spin_unlock(&sbi->fs_lock);
}
+ autofs4_del_active(dentry);
+
/*
- * If we are still pending, check if we had to handle
+ * If we had a mount fail, check if we had to handle
* a signal. If so we can force a restart..
*/
- if (dentry->d_flags & DCACHE_AUTOFS_PENDING) {
+ if (status) {
/* See if we were interrupted */
if (signal_pending(current)) {
sigset_t *sigset = &current->pending.signal;
if (sigismember (sigset, SIGKILL) ||
sigismember (sigset, SIGQUIT) ||
sigismember (sigset, SIGINT)) {
- if (unhashed)
- dput(unhashed);
+ if (active)
+ dput(active);
return ERR_PTR(-ERESTARTNOINTR);
}
}
- if (!oz_mode) {
- spin_lock(&dentry->d_lock);
- dentry->d_flags &= ~DCACHE_AUTOFS_PENDING;
- spin_unlock(&dentry->d_lock);
+ }
+
+ /*
+ * User space can (and has done in the past) remove and re-create
+ * this directory during the callback. This can leave us with an
+ * unhashed dentry, but a successful mount! So we need to
+ * perform another cached lookup in case the dentry now exists.
+ */
+ if (!oz_mode && !have_submounts(dentry)) {
+ struct dentry *new;
+ new = d_lookup(dentry->d_parent, &dentry->d_name);
+ if (new) {
+ if (active)
+ dput(active);
+ return new;
+ } else {
+ if (!status)
+ status = -ENOENT;
}
}
/*
- * If this dentry is unhashed, then we shouldn't honour this
- * lookup. Returning ENOENT here doesn't do the right thing
- * for all system calls, but it should be OK for the operations
- * we permit from an autofs.
+ * If we had a mount failure, return status to user space.
+ * If the mount succeeded and we used a dentry from the active queue
+ * return it.
*/
- if (!oz_mode && d_unhashed(dentry)) {
+ if (status) {
+ dentry = ERR_PTR(status);
+ if (active)
+ dput(active);
+ return dentry;
+ } else {
/*
- * 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.
+ * Valid successful mount, return active dentry or NULL
+ * for a new dentry.
*/
- 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 (unhashed)
- dput(unhashed);
-
- return dentry;
+ if (active)
+ return active;
}
- if (unhashed)
- return unhashed;
-
return NULL;
}
@@ -624,11 +834,6 @@ static int autofs4_dir_symlink(struct inode *dir,
if (!ino)
return -ENOMEM;
- spin_lock(&sbi->lookup_lock);
- if (!list_empty(&ino->active))
- list_del_init(&ino->active);
- spin_unlock(&sbi->lookup_lock);
-
ino->size = strlen(symname);
cp = kmalloc(ino->size + 1, GFP_KERNEL);
if (!cp) {
@@ -705,10 +910,6 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
dir->i_mtime = CURRENT_TIME;
spin_lock(&dcache_lock);
- spin_lock(&sbi->lookup_lock);
- if (list_empty(&ino->expiring))
- list_add(&ino->expiring, &sbi->expiring_list);
- spin_unlock(&sbi->lookup_lock);
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
@@ -734,10 +935,6 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
spin_unlock(&dcache_lock);
return -ENOTEMPTY;
}
- spin_lock(&sbi->lookup_lock);
- if (list_empty(&ino->expiring))
- list_add(&ino->expiring, &sbi->expiring_list);
- spin_unlock(&sbi->lookup_lock);
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
@@ -775,11 +972,6 @@ static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode)
if (!ino)
return -ENOMEM;
- spin_lock(&sbi->lookup_lock);
- if (!list_empty(&ino->active))
- list_del_init(&ino->active);
- spin_unlock(&sbi->lookup_lock);
-
inode = autofs4_get_inode(dir->i_sb, ino);
if (!inode) {
if (!dentry->d_fsdata)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-12 16:58:53 +0000