CIFS: Implement caching mechanism for posix brlocks
to handle all lock requests on the client in an exclusive oplock case.
Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 34cbbee..805e2bd 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -788,7 +788,42 @@
}
static int
-cifs_push_locks(struct cifsFileInfo *cfile)
+cifs_posix_lock_test(struct file *file, struct file_lock *flock)
+{
+ int rc = 0;
+ struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode);
+ unsigned char saved_type = flock->fl_type;
+
+ mutex_lock(&cinode->lock_mutex);
+ posix_test_lock(file, flock);
+
+ if (flock->fl_type == F_UNLCK && !cinode->can_cache_brlcks) {
+ flock->fl_type = saved_type;
+ rc = 1;
+ }
+
+ mutex_unlock(&cinode->lock_mutex);
+ return rc;
+}
+
+static int
+cifs_posix_lock_set(struct file *file, struct file_lock *flock)
+{
+ struct cifsInodeInfo *cinode = CIFS_I(file->f_path.dentry->d_inode);
+ int rc;
+
+ mutex_lock(&cinode->lock_mutex);
+ if (!cinode->can_cache_brlcks) {
+ mutex_unlock(&cinode->lock_mutex);
+ return 1;
+ }
+ rc = posix_lock_file_wait(file, flock);
+ mutex_unlock(&cinode->lock_mutex);
+ return rc;
+}
+
+static int
+cifs_push_mandatory_locks(struct cifsFileInfo *cfile)
{
int xid, rc = 0, stored_rc;
struct cifsLockInfo *li, *tmp;
@@ -820,6 +855,91 @@
return rc;
}
+/* copied from fs/locks.c with a name change */
+#define cifs_for_each_lock(inode, lockp) \
+ for (lockp = &inode->i_flock; *lockp != NULL; \
+ lockp = &(*lockp)->fl_next)
+
+static int
+cifs_push_posix_locks(struct cifsFileInfo *cfile)
+{
+ struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+ struct file_lock *flock, **before;
+ struct cifsLockInfo *lck, *tmp;
+ int rc = 0, xid, type;
+ __u64 length;
+ struct list_head locks_to_send;
+
+ xid = GetXid();
+
+ mutex_lock(&cinode->lock_mutex);
+ if (!cinode->can_cache_brlcks) {
+ mutex_unlock(&cinode->lock_mutex);
+ FreeXid(xid);
+ return rc;
+ }
+
+ INIT_LIST_HEAD(&locks_to_send);
+
+ lock_flocks();
+ cifs_for_each_lock(cfile->dentry->d_inode, before) {
+ flock = *before;
+ length = 1 + flock->fl_end - flock->fl_start;
+ if (flock->fl_type == F_RDLCK || flock->fl_type == F_SHLCK)
+ type = CIFS_RDLCK;
+ else
+ type = CIFS_WRLCK;
+
+ lck = cifs_lock_init(length, flock->fl_start, type,
+ cfile->netfid);
+ if (!lck) {
+ rc = -ENOMEM;
+ goto send_locks;
+ }
+ lck->pid = flock->fl_pid;
+
+ list_add_tail(&lck->llist, &locks_to_send);
+ }
+
+send_locks:
+ unlock_flocks();
+
+ list_for_each_entry_safe(lck, tmp, &locks_to_send, llist) {
+ struct file_lock tmp_lock;
+ int stored_rc;
+
+ tmp_lock.fl_start = lck->offset;
+ stored_rc = CIFSSMBPosixLock(xid, tcon, lck->netfid, lck->pid,
+ 0, lck->length, &tmp_lock,
+ lck->type, 0);
+ if (stored_rc)
+ rc = stored_rc;
+ list_del(&lck->llist);
+ kfree(lck);
+ }
+
+ cinode->can_cache_brlcks = false;
+ mutex_unlock(&cinode->lock_mutex);
+
+ FreeXid(xid);
+ return rc;
+}
+
+static int
+cifs_push_locks(struct cifsFileInfo *cfile)
+{
+ struct cifs_sb_info *cifs_sb = CIFS_SB(cfile->dentry->d_sb);
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
+
+ if ((tcon->ses->capabilities & CAP_UNIX) &&
+ (CIFS_UNIX_FCNTL_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability)) &&
+ ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0))
+ return cifs_push_posix_locks(cfile);
+
+ return cifs_push_mandatory_locks(cfile);
+}
+
static void
cifs_read_flock(struct file_lock *flock, __u8 *type, int *lock, int *unlock,
bool *wait_flag)
@@ -865,24 +985,30 @@
}
static int
-cifs_getlk(struct cifsFileInfo *cfile, struct file_lock *flock, __u8 type,
+cifs_getlk(struct file *file, struct file_lock *flock, __u8 type,
bool wait_flag, bool posix_lck, int xid)
{
int rc = 0;
__u64 length = 1 + flock->fl_end - flock->fl_start;
+ struct cifsFileInfo *cfile = (struct cifsFileInfo *)file->private_data;
+ struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
struct cifsInodeInfo *cinode = CIFS_I(cfile->dentry->d_inode);
__u16 netfid = cfile->netfid;
- struct cifs_tcon *tcon = tlink_tcon(cfile->tlink);
if (posix_lck) {
int posix_lock_type;
+
+ rc = cifs_posix_lock_test(file, flock);
+ if (!rc)
+ return rc;
+
if (type & LOCKING_ANDX_SHARED_LOCK)
posix_lock_type = CIFS_RDLCK;
else
posix_lock_type = CIFS_WRLCK;
- rc = CIFSSMBPosixLock(xid, tcon, netfid, 1 /* get */,
- length, flock, posix_lock_type,
- wait_flag);
+ rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
+ 1 /* get */, length, flock,
+ posix_lock_type, wait_flag);
return rc;
}
@@ -944,6 +1070,11 @@
if (posix_lck) {
int posix_lock_type;
+
+ rc = cifs_posix_lock_set(file, flock);
+ if (!rc || rc < 0)
+ return rc;
+
if (type & LOCKING_ANDX_SHARED_LOCK)
posix_lock_type = CIFS_RDLCK;
else
@@ -952,8 +1083,9 @@
if (unlock == 1)
posix_lock_type = CIFS_UNLCK;
- rc = CIFSSMBPosixLock(xid, tcon, netfid, 0 /* set */, length,
- flock, posix_lock_type, wait_flag);
+ rc = CIFSSMBPosixLock(xid, tcon, netfid, current->tgid,
+ 0 /* set */, length, flock,
+ posix_lock_type, wait_flag);
goto out;
}
@@ -1052,7 +1184,7 @@
* negative length which we can not accept over the wire.
*/
if (IS_GETLK(cmd)) {
- rc = cifs_getlk(cfile, flock, type, wait_flag, posix_lck, xid);
+ rc = cifs_getlk(file, flock, type, wait_flag, posix_lck, xid);
FreeXid(xid);
return rc;
}