The patch titled
autofs4: reorganize expire pending wait function calls
has been added to the -mm tree. Its filename is
autofs4-reorganize-expire-pending-wait-function-calls.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: autofs4: reorganize expire pending wait function calls
From: Ian Kent <raven@xxxxxxxxxx>
This patch re-orgnirzes the checking for and waiting on active expires and
elininates redundant checks.
Signed-off-by: Ian Kent <raven@xxxxxxxxxx>
Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/autofs4/autofs_i.h | 1
fs/autofs4/expire.c | 29 +++++++++++++++
fs/autofs4/root.c | 75 +++++-----------------------------------
3 files changed, 40 insertions(+), 65 deletions(-)
diff -puN fs/autofs4/autofs_i.h~autofs4-reorganize-expire-pending-wait-function-calls fs/autofs4/autofs_i.h
--- a/fs/autofs4/autofs_i.h~autofs4-reorganize-expire-pending-wait-function-calls
+++ a/fs/autofs4/autofs_i.h
@@ -163,6 +163,7 @@ void autofs4_free_ino(struct autofs_info
/* Expiration */
int is_autofs4_dentry(struct dentry *);
+int autofs4_expire_wait(struct dentry *dentry);
int autofs4_expire_run(struct super_block *, struct vfsmount *,
struct autofs_sb_info *,
struct autofs_packet_expire __user *);
diff -puN fs/autofs4/expire.c~autofs4-reorganize-expire-pending-wait-function-calls fs/autofs4/expire.c
--- a/fs/autofs4/expire.c~autofs4-reorganize-expire-pending-wait-function-calls
+++ a/fs/autofs4/expire.c
@@ -402,6 +402,35 @@ found:
return expired;
}
+int autofs4_expire_wait(struct dentry *dentry)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
+ struct autofs_info *ino = autofs4_dentry_ino(dentry);
+ int status;
+
+ /* Block on any pending expire */
+ spin_lock(&sbi->fs_lock);
+ if (ino->flags & AUTOFS_INF_EXPIRING) {
+ spin_unlock(&sbi->fs_lock);
+
+ DPRINTK("waiting for expire %p name=%.*s",
+ dentry, dentry->d_name.len, dentry->d_name.name);
+
+ status = autofs4_wait(sbi, dentry, NFY_NONE);
+ wait_for_completion(&ino->expire_complete);
+
+ DPRINTK("expire done status=%d", status);
+
+ if (d_unhashed(dentry))
+ return -EAGAIN;
+
+ return status;
+ }
+ spin_unlock(&sbi->fs_lock);
+
+ return 0;
+}
+
/* Perform an expiry operation */
int autofs4_expire_run(struct super_block *sb,
struct vfsmount *mnt,
diff -puN fs/autofs4/root.c~autofs4-reorganize-expire-pending-wait-function-calls fs/autofs4/root.c
--- a/fs/autofs4/root.c~autofs4-reorganize-expire-pending-wait-function-calls
+++ a/fs/autofs4/root.c
@@ -130,34 +130,6 @@ static int try_to_fill_dentry(struct den
struct autofs_info *ino = autofs4_dentry_ino(dentry);
int status;
- /* Block on any pending expiry here; invalidate the dentry
- when expiration is done to trigger mount request with a new
- dentry */
- spin_lock(&sbi->fs_lock);
- if (ino->flags & AUTOFS_INF_EXPIRING) {
- spin_unlock(&sbi->fs_lock);
-
- DPRINTK("waiting for expire %p name=%.*s",
- dentry, dentry->d_name.len, dentry->d_name.name);
-
- status = autofs4_wait(sbi, dentry, NFY_NONE);
- wait_for_completion(&ino->expire_complete);
-
- DPRINTK("expire done status=%d", status);
-
- /*
- * If the directory still exists the mount request must
- * continue otherwise it can't be followed at the right
- * time during the walk.
- */
- status = d_invalidate(dentry);
- if (status != -EBUSY)
- return -EAGAIN;
-
- goto cont;
- }
- spin_unlock(&sbi->fs_lock);
-cont:
DPRINTK("dentry=%p %.*s ino=%p",
dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode);
@@ -254,22 +226,8 @@ static void *autofs4_follow_link(struct
}
/* If an expire request is pending everyone must wait. */
- spin_lock(&sbi->fs_lock);
- if (ino->flags & AUTOFS_INF_EXPIRING) {
- spin_unlock(&sbi->fs_lock);
-
- DPRINTK("waiting for active request %p name=%.*s",
- dentry, dentry->d_name.len, dentry->d_name.name);
-
- status = autofs4_wait(sbi, dentry, NFY_NONE);
- wait_for_completion(&ino->expire_complete);
+ autofs4_expire_wait(dentry);
- DPRINTK("request done status=%d", status);
-
- goto cont;
- }
- spin_unlock(&sbi->fs_lock);
-cont:
/* 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))
@@ -338,6 +296,14 @@ static int autofs4_revalidate(struct den
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.
*/
@@ -345,15 +311,6 @@ static int autofs4_revalidate(struct den
if (status == 0)
return 1;
- /*
- * A status of EAGAIN here means that the dentry has gone
- * away while waiting for an expire to complete. If we are
- * racing with expire lookup will wait for it so this must
- * be a revalidate and we need to send it to lookup.
- */
- if (status == -EAGAIN)
- return 0;
-
return status;
}
spin_unlock(&sbi->fs_lock);
@@ -563,19 +520,7 @@ static struct dentry *autofs4_lookup(str
* so it must have been successful, so just wait for it.
*/
ino = autofs4_dentry_ino(expiring);
- spin_lock(&sbi->fs_lock);
- if (ino->flags & AUTOFS_INF_EXPIRING) {
- spin_unlock(&sbi->fs_lock);
- DPRINTK("wait for incomplete expire %p name=%.*s",
- expiring, expiring->d_name.len,
- expiring->d_name.name);
- autofs4_wait(sbi, expiring, NFY_NONE);
- wait_for_completion(&ino->expire_complete);
- DPRINTK("request completed");
- goto cont;
- }
- spin_unlock(&sbi->fs_lock);
-cont:
+ autofs4_expire_wait(expiring);
spin_lock(&sbi->lookup_lock);
if (!list_empty(&ino->expiring))
list_del_init(&ino->expiring);
_
Patches currently in -mm which might be from raven@xxxxxxxxxx are
autofs4-dont-make-expiring-dentry-negative.patch
autofs4-dont-make-expiring-dentry-negative-fix.patch
autofs4-revert-redo-lookup-in-ttfd.patch
autofs4-use-look-aside-list-for-lookups.patch
autofs4-use-look-aside-list-for-lookups-autofs4-fix-symlink-name-allocation.patch
autofs4-dont-release-directory-mutex-if-called-in-oz_mode.patch
autofs4-use-lookup-intent-flags-to-trigger-mounts.patch
autofs4-use-struct-qstr-in-waitqc.patch
autofs4-fix-waitq-locking.patch
autofs4-fix-pending-mount-race.patch
autofs4-fix-pending-mount-race-fix.patch
autofs4-check-kernel-communication-pipe-is-valid-for-write.patch
autofs4-fix-waitq-memory-leak.patch
autofs4-detect-invalid-direct-mount-requests.patch
autofs4-indirect-dentry-must-almost-always-be-positive.patch
autofs4-cleanup-redundant-readir-code.patch
autofs4-fix-pending-checks.patch
autofs4-fix-indirect-mount-pending-expire-race.patch
autofs4-fix-direct-mount-pending-expire-race.patch
autofs4-reorganize-expire-pending-wait-function-calls.patch
autofs4-remove-unused-ioctls.patch
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