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yaml
---
r: 105455
b: refs/heads/master
c: 5f6f4f2
h: refs/heads/master
i:
  105453: a8cc788
  105451: 9a6111b
  105447: ef7445f
  105439: ddfdb8e
v: v3
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Ian Kent authored and Linus Torvalds committed Jul 24, 2008
1 parent 9be8b46 commit 42df4ee
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Showing 4 changed files with 53 additions and 79 deletions.
2 changes: 1 addition & 1 deletion [refs]
Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 391b52f98cf2e9bff227dad8bf9ea206fec43fa4
refs/heads/master: 5f6f4f28b6ba543beef8bad91aa6f69c7ffeee51
6 changes: 3 additions & 3 deletions trunk/fs/autofs4/autofs_i.h
Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,7 @@ struct autofs_info {

int flags;

struct list_head rehash;
struct list_head expiring;

struct autofs_sb_info *sbi;
unsigned long last_used;
Expand Down Expand Up @@ -112,8 +112,8 @@ struct autofs_sb_info {
struct mutex wq_mutex;
spinlock_t fs_lock;
struct autofs_wait_queue *queues; /* Wait queue pointer */
spinlock_t rehash_lock;
struct list_head rehash_list;
spinlock_t lookup_lock;
struct list_head expiring_list;
};

static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb)
Expand Down
6 changes: 3 additions & 3 deletions trunk/fs/autofs4/inode.c
Original file line number Diff line number Diff line change
Expand Up @@ -47,7 +47,7 @@ struct autofs_info *autofs4_init_ino(struct autofs_info *ino,
ino->dentry = NULL;
ino->size = 0;

INIT_LIST_HEAD(&ino->rehash);
INIT_LIST_HEAD(&ino->expiring);

ino->last_used = jiffies;
atomic_set(&ino->count, 0);
Expand Down Expand Up @@ -338,8 +338,8 @@ int autofs4_fill_super(struct super_block *s, void *data, int silent)
mutex_init(&sbi->wq_mutex);
spin_lock_init(&sbi->fs_lock);
sbi->queues = NULL;
spin_lock_init(&sbi->rehash_lock);
INIT_LIST_HEAD(&sbi->rehash_list);
spin_lock_init(&sbi->lookup_lock);
INIT_LIST_HEAD(&sbi->expiring_list);
s->s_blocksize = 1024;
s->s_blocksize_bits = 10;
s->s_magic = AUTOFS_SUPER_MAGIC;
Expand Down
118 changes: 46 additions & 72 deletions trunk/fs/autofs4/root.c
Original file line number Diff line number Diff line change
Expand Up @@ -493,10 +493,10 @@ void autofs4_dentry_release(struct dentry *de)
struct autofs_sb_info *sbi = autofs4_sbi(de->d_sb);

if (sbi) {
spin_lock(&sbi->rehash_lock);
if (!list_empty(&inf->rehash))
list_del(&inf->rehash);
spin_unlock(&sbi->rehash_lock);
spin_lock(&sbi->lookup_lock);
if (!list_empty(&inf->expiring))
list_del(&inf->expiring);
spin_unlock(&sbi->lookup_lock);
}

inf->dentry = NULL;
Expand All @@ -518,22 +518,22 @@ static struct dentry_operations autofs4_dentry_operations = {
.d_release = autofs4_dentry_release,
};

static struct dentry *autofs4_lookup_unhashed(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
static struct dentry *autofs4_lookup_expiring(struct autofs_sb_info *sbi, struct dentry *parent, struct qstr *name)
{
unsigned int len = name->len;
unsigned int hash = name->hash;
const unsigned char *str = name->name;
struct list_head *p, *head;

spin_lock(&dcache_lock);
spin_lock(&sbi->rehash_lock);
head = &sbi->rehash_list;
spin_lock(&sbi->lookup_lock);
head = &sbi->expiring_list;
list_for_each(p, head) {
struct autofs_info *ino;
struct dentry *dentry;
struct qstr *qstr;

ino = list_entry(p, struct autofs_info, rehash);
ino = list_entry(p, struct autofs_info, expiring);
dentry = ino->dentry;

spin_lock(&dentry->d_lock);
Expand All @@ -555,33 +555,16 @@ static struct dentry *autofs4_lookup_unhashed(struct autofs_sb_info *sbi, struct
goto next;

if (d_unhashed(dentry)) {
struct inode *inode = dentry->d_inode;

ino = autofs4_dentry_ino(dentry);
list_del_init(&ino->rehash);
dget(dentry);
/*
* Make the rehashed dentry negative so the VFS
* behaves as it should.
*/
if (inode) {
dentry->d_inode = NULL;
list_del_init(&dentry->d_alias);
spin_unlock(&dentry->d_lock);
spin_unlock(&sbi->rehash_lock);
spin_unlock(&dcache_lock);
iput(inode);
return dentry;
}
spin_unlock(&dentry->d_lock);
spin_unlock(&sbi->rehash_lock);
spin_unlock(&sbi->lookup_lock);
spin_unlock(&dcache_lock);
return dentry;
}
next:
spin_unlock(&dentry->d_lock);
}
spin_unlock(&sbi->rehash_lock);
spin_unlock(&sbi->lookup_lock);
spin_unlock(&dcache_lock);

return NULL;
Expand All @@ -591,7 +574,7 @@ static struct dentry *autofs4_lookup_unhashed(struct autofs_sb_info *sbi, struct
static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
{
struct autofs_sb_info *sbi;
struct dentry *unhashed;
struct dentry *expiring;
int oz_mode;

DPRINTK("name = %.*s",
Expand All @@ -607,44 +590,44 @@ 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_unhashed(sbi, dentry->d_parent, &dentry->d_name);
if (!unhashed) {
/*
* 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;

dentry->d_fsdata = NULL;
d_instantiate(dentry, NULL);
} else {
struct autofs_info *ino = autofs4_dentry_ino(unhashed);
DPRINTK("rehash %p with %p", dentry, unhashed);
expiring = autofs4_lookup_expiring(sbi, dentry->d_parent, &dentry->d_name);
if (expiring) {
struct autofs_info *ino = autofs4_dentry_ino(expiring);
/*
* If we are racing with expire the request might not
* be quite complete but the directory has been removed
* so it must have been successful, so just wait for it.
* We need to ensure the AUTOFS_INF_EXPIRING flag is clear
* before continuing as revalidate may fail when calling
* try_to_fill_dentry (returning EAGAIN) if we don't.
*/
while (ino && (ino->flags & AUTOFS_INF_EXPIRING)) {
DPRINTK("wait for incomplete expire %p name=%.*s",
unhashed, unhashed->d_name.len,
unhashed->d_name.name);
autofs4_wait(sbi, unhashed, NFY_NONE);
expiring, expiring->d_name.len,
expiring->d_name.name);
autofs4_wait(sbi, expiring, NFY_NONE);
DPRINTK("request completed");
}
dentry = unhashed;
spin_lock(&sbi->lookup_lock);
if (!list_empty(&ino->expiring))
list_del_init(&ino->expiring);
spin_unlock(&sbi->lookup_lock);
dput(expiring);
}

/*
* Mark the dentry incomplete but don't hash it. We do this
* to serialize our inode creation operations (symlink and
* mkdir) which prevents deadlock during the callback to
* the daemon. Subsequent user space lookups for the same
* dentry are placed on the wait queue while the daemon
* itself is allowed passage unresticted so the create
* operation itself can then hash the dentry. Finally,
* we check for the hashed dentry and return the newly
* hashed dentry.
*/
dentry->d_op = &autofs4_root_dentry_operations;

dentry->d_fsdata = NULL;
d_instantiate(dentry, NULL);

if (!oz_mode) {
spin_lock(&dentry->d_lock);
dentry->d_flags |= DCACHE_AUTOFS_PENDING;
Expand All @@ -668,8 +651,6 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
if (sigismember (sigset, SIGKILL) ||
sigismember (sigset, SIGQUIT) ||
sigismember (sigset, SIGINT)) {
if (unhashed)
dput(unhashed);
return ERR_PTR(-ERESTARTNOINTR);
}
}
Expand Down Expand Up @@ -699,15 +680,9 @@ static struct dentry *autofs4_lookup(struct inode *dir, struct dentry *dentry, s
else
dentry = ERR_PTR(-ENOENT);

if (unhashed)
dput(unhashed);

return dentry;
}

if (unhashed)
return dentry;

return NULL;
}

Expand Down Expand Up @@ -769,9 +744,8 @@ static int autofs4_dir_symlink(struct inode *dir,
* that the file no longer exists. However, doing that means that the
* VFS layer can turn the dentry into a negative dentry. We don't want
* this, because the unlink is probably the result of an expire.
* We simply d_drop it and add it to a rehash candidates list in the
* super block, which allows the dentry lookup to reuse it retaining
* the flags, such as expire in progress, in case we're racing with expire.
* We simply d_drop it and add it to a expiring list in the super block,
* which allows the dentry lookup to check for an incomplete expire.
*
* If a process is blocked on the dentry waiting for the expire to finish,
* it will invalidate the dentry and try to mount with a new one.
Expand Down Expand Up @@ -801,9 +775,9 @@ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry)
dir->i_mtime = CURRENT_TIME;

spin_lock(&dcache_lock);
spin_lock(&sbi->rehash_lock);
list_add(&ino->rehash, &sbi->rehash_list);
spin_unlock(&sbi->rehash_lock);
spin_lock(&sbi->lookup_lock);
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);
Expand All @@ -829,9 +803,9 @@ static int autofs4_dir_rmdir(struct inode *dir, struct dentry *dentry)
spin_unlock(&dcache_lock);
return -ENOTEMPTY;
}
spin_lock(&sbi->rehash_lock);
list_add(&ino->rehash, &sbi->rehash_list);
spin_unlock(&sbi->rehash_lock);
spin_lock(&sbi->lookup_lock);
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);
Expand Down

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