From 1b4b55a1d9404f51aacf1ff19887eb911484057d Mon Sep 17 00:00:00 2001 From: Pavel Shilovsky Date: Wed, 19 Sep 2012 06:22:44 -0700 Subject: [PATCH] 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 Signed-off-by: Steve French --- fs/cifs/cifsfs.c | 2 +- fs/cifs/cifsglob.h | 2 +- fs/cifs/file.c | 60 ++++++++++++++++++++++++---------------------- fs/cifs/smb2file.c | 15 ++++++------ 4 files changed, 41 insertions(+), 38 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index e958d9438505..4cd68c77ce39 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -937,7 +937,7 @@ cifs_init_once(void *inode) struct cifsInodeInfo *cifsi = inode; inode_init_once(&cifsi->vfs_inode); - mutex_init(&cifsi->lock_mutex); + init_rwsem(&cifsi->lock_sem); } static int diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index d3c72713fec4..e2492e1cdb85 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -1000,7 +1000,7 @@ void cifsFileInfo_put(struct cifsFileInfo *cifs_file); struct cifsInodeInfo { bool can_cache_brlcks; struct list_head llist; /* locks helb by this inode */ - struct mutex lock_mutex; /* protect the fields above */ + struct rw_semaphore lock_sem; /* protect the fields above */ /* BB add in lists for dirty pages i.e. write caching info for oplock */ struct list_head openFileList; __u32 cifsAttrs; /* e.g. DOS archive bit, sparse, compressed, system */ 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; } diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c index 181e13d9f9db..0ddd617ffa1a 100644 --- a/fs/cifs/smb2file.c +++ b/fs/cifs/smb2file.c @@ -135,7 +135,7 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, cur = buf; - mutex_lock(&cinode->lock_mutex); + down_write(&cinode->lock_sem); list_for_each_entry_safe(li, tmp, &cfile->llist->locks, llist) { if (flock->fl_start > li->offset || (flock->fl_start + length) < @@ -196,7 +196,7 @@ smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, } else cifs_free_llist(&tmp_llist); } - mutex_unlock(&cinode->lock_mutex); + up_write(&cinode->lock_sem); kfree(buf); return rc; @@ -253,9 +253,10 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) struct cifs_fid_locks *fdlocks; 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; } @@ -266,7 +267,7 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) */ max_buf = tlink_tcon(cfile->tlink)->ses->server->maxBuf; if (!max_buf) { - mutex_unlock(&cinode->lock_mutex); + up_write(&cinode->lock_sem); free_xid(xid); return -EINVAL; } @@ -274,7 +275,7 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) max_num = max_buf / sizeof(struct smb2_lock_element); buf = kzalloc(max_num * sizeof(struct smb2_lock_element), GFP_KERNEL); if (!buf) { - mutex_unlock(&cinode->lock_mutex); + up_write(&cinode->lock_sem); free_xid(xid); return -ENOMEM; } @@ -288,7 +289,7 @@ smb2_push_mandatory_locks(struct cifsFileInfo *cfile) cinode->can_cache_brlcks = false; kfree(buf); - mutex_unlock(&cinode->lock_mutex); + up_write(&cinode->lock_sem); free_xid(xid); return rc; } -- 2.20.1