As Kinglong points out, the nlm_block->b_fl field is no longer used at
all. Also, vfs_test_lock in the generic locking code will only return
FILE_LOCK_DEFERRED if FL_SLEEP is set, and it isn't here.
The only other place that returns that value is the DLM lock code, but
it only does that in dlm_posix_lock, never in dlm_posix_get.
Remove all of the deferred locking code from the testlock codepath
since it doesn't appear to ever be used anyway.
I do have a small concern that this might cause a behavior change in the
case where you have a block already sitting on the list when the
testlock request comes in, but that looks like it doesn't really work
properly anyway. I think it's best to just pass that down to
vfs_test_lock and let the filesystem report that instead of trying to
infer what's going on with the lock by looking at an existing block.
Cc: [email protected]
Reported-by: Kinglong Mee <[email protected]>
Signed-off-by: Jeff Layton <[email protected]>
---
fs/lockd/svclock.c | 55 +++++----------------------------------------
include/linux/lockd/lockd.h | 1 -
2 files changed, 6 insertions(+), 50 deletions(-)
diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
index acfa94d5b489..13db95f54176 100644
--- a/fs/lockd/svclock.c
+++ b/fs/lockd/svclock.c
@@ -245,7 +245,6 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host,
block->b_daemon = rqstp->rq_server;
block->b_host = host;
block->b_file = file;
- block->b_fl = NULL;
file->f_count++;
/* Add to file's list of blocks */
@@ -295,7 +294,6 @@ static void nlmsvc_free_block(struct kref *kref)
nlmsvc_freegrantargs(block->b_call);
nlmsvc_release_call(block->b_call);
nlm_release_file(block->b_file);
- kfree(block->b_fl);
kfree(block);
}
@@ -508,7 +506,6 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
struct nlm_host *host, struct nlm_lock *lock,
struct nlm_lock *conflock, struct nlm_cookie *cookie)
{
- struct nlm_block *block = NULL;
int error;
__be32 ret;
@@ -519,63 +516,26 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
(long long)lock->fl.fl_start,
(long long)lock->fl.fl_end);
- /* Get existing block (in case client is busy-waiting) */
- block = nlmsvc_lookup_block(file, lock);
-
- if (block == NULL) {
- struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
-
- if (conf == NULL)
- return nlm_granted;
- block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
- if (block == NULL) {
- kfree(conf);
- return nlm_granted;
- }
- block->b_fl = conf;
- }
- if (block->b_flags & B_QUEUED) {
- dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n",
- block, block->b_flags, block->b_fl);
- if (block->b_flags & B_TIMED_OUT) {
- nlmsvc_unlink_block(block);
- ret = nlm_lck_denied;
- goto out;
- }
- if (block->b_flags & B_GOT_CALLBACK) {
- nlmsvc_unlink_block(block);
- if (block->b_fl != NULL
- && block->b_fl->fl_type != F_UNLCK) {
- lock->fl = *block->b_fl;
- goto conf_lock;
- } else {
- ret = nlm_granted;
- goto out;
- }
- }
- ret = nlm_drop_reply;
- goto out;
- }
-
if (locks_in_grace(SVC_NET(rqstp))) {
ret = nlm_lck_denied_grace_period;
goto out;
}
+
error = vfs_test_lock(file->f_file, &lock->fl);
- if (error == FILE_LOCK_DEFERRED) {
- ret = nlmsvc_defer_lock_rqst(rqstp, block);
- goto out;
- }
if (error) {
+ /* We can't currently deal with deferred test requests */
+ if (error == FILE_LOCK_DEFERRED)
+ WARN_ON_ONCE(1);
+
ret = nlm_lck_denied_nolocks;
goto out;
}
+
if (lock->fl.fl_type == F_UNLCK) {
ret = nlm_granted;
goto out;
}
-conf_lock:
dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
lock->fl.fl_type, (long long)lock->fl.fl_start,
(long long)lock->fl.fl_end);
@@ -589,8 +549,6 @@ conf_lock:
locks_release_private(&lock->fl);
ret = nlm_lck_denied;
out:
- if (block)
- nlmsvc_release_block(block);
return ret;
}
@@ -661,7 +619,6 @@ nlmsvc_cancel_blocked(struct net *net, struct nlm_file *file, struct nlm_lock *l
* This is a callback from the filesystem for VFS file lock requests.
* It will be used if lm_grant is defined and the filesystem can not
* respond to the request immediately.
- * For GETLK request it will copy the reply to the nlm_block.
* For SETLK or SETLKW request it will get the local posix lock.
* In all cases it will move the block to the head of nlm_blocked q where
* nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the
diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
index 219d79627c05..ff82a32871b5 100644
--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -178,7 +178,6 @@ struct nlm_block {
unsigned char b_granted; /* VFS granted lock */
struct nlm_file * b_file; /* file in question */
struct cache_req * b_cache_req; /* deferred request handling */
- struct file_lock * b_fl; /* set for GETLK */
struct cache_deferred_req * b_deferred_req;
unsigned int b_flags; /* block flags */
#define B_QUEUED 1 /* lock queued */
--
1.9.3
I'd like this patch.
Reviewed-by: Kinglong Mee <[email protected]>
On 8/21/2014 23:45, Jeff Layton wrote:
> As Kinglong points out, the nlm_block->b_fl field is no longer used at
> all. Also, vfs_test_lock in the generic locking code will only return
> FILE_LOCK_DEFERRED if FL_SLEEP is set, and it isn't here.
>
> The only other place that returns that value is the DLM lock code, but
> it only does that in dlm_posix_lock, never in dlm_posix_get.
>
> Remove all of the deferred locking code from the testlock codepath
> since it doesn't appear to ever be used anyway.
>
> I do have a small concern that this might cause a behavior change in the
> case where you have a block already sitting on the list when the
> testlock request comes in, but that looks like it doesn't really work
> properly anyway. I think it's best to just pass that down to
> vfs_test_lock and let the filesystem report that instead of trying to
> infer what's going on with the lock by looking at an existing block.
>
> Cc: [email protected]
> Reported-by: Kinglong Mee <[email protected]>
> Signed-off-by: Jeff Layton <[email protected]>
> ---
> fs/lockd/svclock.c | 55 +++++----------------------------------------
> include/linux/lockd/lockd.h | 1 -
> 2 files changed, 6 insertions(+), 50 deletions(-)
>
> diff --git a/fs/lockd/svclock.c b/fs/lockd/svclock.c
> index acfa94d5b489..13db95f54176 100644
> --- a/fs/lockd/svclock.c
> +++ b/fs/lockd/svclock.c
> @@ -245,7 +245,6 @@ nlmsvc_create_block(struct svc_rqst *rqstp, struct nlm_host *host,
> block->b_daemon = rqstp->rq_server;
> block->b_host = host;
> block->b_file = file;
> - block->b_fl = NULL;
> file->f_count++;
>
> /* Add to file's list of blocks */
> @@ -295,7 +294,6 @@ static void nlmsvc_free_block(struct kref *kref)
> nlmsvc_freegrantargs(block->b_call);
> nlmsvc_release_call(block->b_call);
> nlm_release_file(block->b_file);
> - kfree(block->b_fl);
> kfree(block);
> }
>
> @@ -508,7 +506,6 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
> struct nlm_host *host, struct nlm_lock *lock,
> struct nlm_lock *conflock, struct nlm_cookie *cookie)
> {
> - struct nlm_block *block = NULL;
> int error;
> __be32 ret;
>
> @@ -519,63 +516,26 @@ nlmsvc_testlock(struct svc_rqst *rqstp, struct nlm_file *file,
> (long long)lock->fl.fl_start,
> (long long)lock->fl.fl_end);
>
> - /* Get existing block (in case client is busy-waiting) */
> - block = nlmsvc_lookup_block(file, lock);
> -
> - if (block == NULL) {
> - struct file_lock *conf = kzalloc(sizeof(*conf), GFP_KERNEL);
> -
> - if (conf == NULL)
> - return nlm_granted;
> - block = nlmsvc_create_block(rqstp, host, file, lock, cookie);
> - if (block == NULL) {
> - kfree(conf);
> - return nlm_granted;
> - }
> - block->b_fl = conf;
> - }
> - if (block->b_flags & B_QUEUED) {
> - dprintk("lockd: nlmsvc_testlock deferred block %p flags %d fl %p\n",
> - block, block->b_flags, block->b_fl);
> - if (block->b_flags & B_TIMED_OUT) {
> - nlmsvc_unlink_block(block);
> - ret = nlm_lck_denied;
> - goto out;
> - }
> - if (block->b_flags & B_GOT_CALLBACK) {
> - nlmsvc_unlink_block(block);
> - if (block->b_fl != NULL
> - && block->b_fl->fl_type != F_UNLCK) {
> - lock->fl = *block->b_fl;
> - goto conf_lock;
> - } else {
> - ret = nlm_granted;
> - goto out;
> - }
> - }
> - ret = nlm_drop_reply;
> - goto out;
> - }
> -
> if (locks_in_grace(SVC_NET(rqstp))) {
> ret = nlm_lck_denied_grace_period;
> goto out;
> }
> +
> error = vfs_test_lock(file->f_file, &lock->fl);
> - if (error == FILE_LOCK_DEFERRED) {
> - ret = nlmsvc_defer_lock_rqst(rqstp, block);
> - goto out;
> - }
> if (error) {
> + /* We can't currently deal with deferred test requests */
> + if (error == FILE_LOCK_DEFERRED)
> + WARN_ON_ONCE(1);
> +
> ret = nlm_lck_denied_nolocks;
> goto out;
> }
> +
> if (lock->fl.fl_type == F_UNLCK) {
> ret = nlm_granted;
> goto out;
> }
>
> -conf_lock:
> dprintk("lockd: conflicting lock(ty=%d, %Ld-%Ld)\n",
> lock->fl.fl_type, (long long)lock->fl.fl_start,
> (long long)lock->fl.fl_end);
> @@ -589,8 +549,6 @@ conf_lock:
> locks_release_private(&lock->fl);
> ret = nlm_lck_denied;
> out:
> - if (block)
> - nlmsvc_release_block(block);
> return ret;
> }
>
> @@ -661,7 +619,6 @@ nlmsvc_cancel_blocked(struct net *net, struct nlm_file *file, struct nlm_lock *l
> * This is a callback from the filesystem for VFS file lock requests.
> * It will be used if lm_grant is defined and the filesystem can not
> * respond to the request immediately.
> - * For GETLK request it will copy the reply to the nlm_block.
> * For SETLK or SETLKW request it will get the local posix lock.
> * In all cases it will move the block to the head of nlm_blocked q where
> * nlmsvc_retry_blocked() can send back a reply for SETLKW or revisit the
> diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
> index 219d79627c05..ff82a32871b5 100644
> --- a/include/linux/lockd/lockd.h
> +++ b/include/linux/lockd/lockd.h
> @@ -178,7 +178,6 @@ struct nlm_block {
> unsigned char b_granted; /* VFS granted lock */
> struct nlm_file * b_file; /* file in question */
> struct cache_req * b_cache_req; /* deferred request handling */
> - struct file_lock * b_fl; /* set for GETLK */
> struct cache_deferred_req * b_deferred_req;
> unsigned int b_flags; /* block flags */
> #define B_QUEUED 1 /* lock queued */
>