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Diffstat (limited to 'fs/autofs4/root.c')
-rw-r--r--fs/autofs4/root.c118
1 files changed, 46 insertions, 72 deletions
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index edf5b6bddb5..9ead2279df4 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -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;
@@ -518,7 +518,7 @@ 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;
@@ -526,14 +526,14 @@ static struct dentry *autofs4_lookup_unhashed(struct autofs_sb_info *sbi, struct
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);
@@ -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;
@@ -591,7 +574,7 @@ next:
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",
@@ -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;
@@ -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);
}
}
@@ -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;
}
@@ -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.
@@ -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);
@@ -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);
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-01 09:41:47 +0000