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authorPavel Shilovsky <pshilovsky@etersoft.ru>2012-09-19 06:22:44 -0700
committerSteve French <smfrench@gmail.com>2012-09-24 21:46:33 -0500
commit1b4b55a1d9404f51aacf1ff19887eb911484057d (patch)
treee2909277cc8db445c1d839c4859449a32cbfc08a /fs/cifs/file.c
parentb140799a11adb6023d5f96712874c37b71dab290 (diff)
downloadlwn-1b4b55a1d9404f51aacf1ff19887eb911484057d.tar.gz
lwn-1b4b55a1d9404f51aacf1ff19887eb911484057d.zip
CIFS: Turn lock mutex into rw semaphore
and allow several processes to walk through the lock list and read can_cache_brlcks value if they are not going to modify them. Signed-off-by: Pavel Shilovsky <pshilovsky@etersoft.ru> Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs/cifs/file.c')
-rw-r--r--fs/cifs/file.c60
1 files changed, 31 insertions, 29 deletions
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index e2a8e4456275..1adff75dfffc 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -260,9 +260,9 @@ cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
INIT_LIST_HEAD(&fdlocks->locks);
fdlocks->cfile = cfile;
cfile->llist = fdlocks;
- mutex_lock(&cinode->lock_mutex);
+ down_write(&cinode->lock_sem);
list_add(&fdlocks->llist, &cinode->llist);
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
cfile->count = 1;
cfile->pid = current->tgid;
@@ -351,7 +351,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
* Delete any outstanding lock records. We'll lose them when the file
* is closed anyway.
*/
- mutex_lock(&cifsi->lock_mutex);
+ down_write(&cifsi->lock_sem);
list_for_each_entry_safe(li, tmp, &cifs_file->llist->locks, llist) {
list_del(&li->llist);
cifs_del_lock_waiters(li);
@@ -359,7 +359,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file)
}
list_del(&cifs_file->llist->llist);
kfree(cifs_file->llist);
- mutex_unlock(&cifsi->lock_mutex);
+ up_write(&cifsi->lock_sem);
cifs_put_tlink(cifs_file->tlink);
dput(cifs_file->dentry);
@@ -762,7 +762,7 @@ cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
struct TCP_Server_Info *server = tlink_tcon(cfile->tlink)->ses->server;
bool exist;
- mutex_lock(&cinode->lock_mutex);
+ down_read(&cinode->lock_sem);
exist = cifs_find_lock_conflict(cfile, offset, length, type,
&conf_lock);
@@ -779,7 +779,7 @@ cifs_lock_test(struct cifsFileInfo *cfile, __u64 offset, __u64 length,
else
flock->fl_type = F_UNLCK;
- mutex_unlock(&cinode->lock_mutex);
+ up_read(&cinode->lock_sem);
return rc;
}
@@ -787,9 +787,9 @@ static void
cifs_lock_add(struct cifsFileInfo *cfile, struct cifsLockInfo *lock)
{
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
- mutex_lock(&cinode->lock_mutex);
+ down_write(&cinode->lock_sem);
list_add_tail(&lock->llist, &cfile->llist->locks);
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
}
/*
@@ -809,13 +809,13 @@ cifs_lock_add_if(struct cifsFileInfo *cfile, struct cifsLockInfo *lock,
try_again:
exist = false;
- mutex_lock(&cinode->lock_mutex);
+ down_write(&cinode->lock_sem);
exist = cifs_find_lock_conflict(cfile, lock->offset, lock->length,
lock->type, &conf_lock);
if (!exist && cinode->can_cache_brlcks) {
list_add_tail(&lock->llist, &cfile->llist->locks);
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
return rc;
}
@@ -825,17 +825,17 @@ try_again:
rc = -EACCES;
else {
list_add_tail(&lock->blist, &conf_lock->blist);
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
rc = wait_event_interruptible(lock->block_q,
(lock->blist.prev == &lock->blist) &&
(lock->blist.next == &lock->blist));
if (!rc)
goto try_again;
- mutex_lock(&cinode->lock_mutex);
+ down_write(&cinode->lock_sem);
list_del_init(&lock->blist);
}
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
return rc;
}
@@ -856,7 +856,7 @@ cifs_posix_lock_test(struct file *file, struct file_lock *flock)
if ((flock->fl_flags & FL_POSIX) == 0)
return 1;
- mutex_lock(&cinode->lock_mutex);
+ down_read(&cinode->lock_sem);
posix_test_lock(file, flock);
if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
@@ -864,7 +864,7 @@ cifs_posix_lock_test(struct file *file, struct file_lock *flock)
rc = 1;
}
- mutex_unlock(&cinode->lock_mutex);
+ up_read(&cinode->lock_sem);
return rc;
}
@@ -884,14 +884,14 @@ cifs_posix_lock_set(struct file *file, struct file_lock *flock)
return rc;
try_again:
- mutex_lock(&cinode->lock_mutex);
+ down_write(&cinode->lock_sem);
if (!cinode->can_cache_brlcks) {
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
return rc;
}
rc = posix_lock_file(file, flock, NULL);
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
if (rc == FILE_LOCK_DEFERRED) {
rc = wait_event_interruptible(flock->fl_wait, !flock->fl_next);
if (!rc)
@@ -918,9 +918,10 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
xid = get_xid();
tcon = tlink_tcon(cfile->tlink);
- mutex_lock(&cinode->lock_mutex);
+ /* we are going to update can_cache_brlcks here - need a write access */
+ down_write(&cinode->lock_sem);
if (!cinode->can_cache_brlcks) {
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
free_xid(xid);
return rc;
}
@@ -931,7 +932,7 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
*/
max_buf = tcon->ses->server->maxBuf;
if (!max_buf) {
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
free_xid(xid);
return -EINVAL;
}
@@ -940,7 +941,7 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
sizeof(LOCKING_ANDX_RANGE);
buf = kzalloc(max_num * sizeof(LOCKING_ANDX_RANGE), GFP_KERNEL);
if (!buf) {
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
free_xid(xid);
return -ENOMEM;
}
@@ -978,7 +979,7 @@ cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
}
cinode->can_cache_brlcks = false;
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
kfree(buf);
free_xid(xid);
@@ -1013,9 +1014,10 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile)
xid = get_xid();
- mutex_lock(&cinode->lock_mutex);
+ /* we are going to update can_cache_brlcks here - need a write access */
+ down_write(&cinode->lock_sem);
if (!cinode->can_cache_brlcks) {
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
free_xid(xid);
return rc;
}
@@ -1031,7 +1033,7 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile)
/*
* Allocating count locks is enough because no FL_POSIX locks can be
- * added to the list while we are holding cinode->lock_mutex that
+ * added to the list while we are holding cinode->lock_sem that
* protects locking operations of this inode.
*/
for (; i < count; i++) {
@@ -1086,7 +1088,7 @@ cifs_push_posix_locks(struct cifsFileInfo *cfile)
out:
cinode->can_cache_brlcks = false;
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
free_xid(xid);
return rc;
@@ -1278,7 +1280,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
if (!buf)
return -ENOMEM;
- mutex_lock(&cinode->lock_mutex);
+ down_write(&cinode->lock_sem);
for (i = 0; i < 2; i++) {
cur = buf;
num = 0;
@@ -1348,7 +1350,7 @@ cifs_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock,
}
}
- mutex_unlock(&cinode->lock_mutex);
+ up_write(&cinode->lock_sem);
kfree(buf);
return rc;
}