ipc/mqueue.c: refactor failure handling
Jiri Slaby [Tue, 26 Jul 2011 23:08:46 +0000 (16:08 -0700)]
If new_inode fails to allocate an inode we need only to return with
NULL.  But now we test the opposite and have all the work in a nested
block.  So do the opposite to save one indentation level (and remove
unnecessary line breaks).

This is only a preparation/cleanup for the next patch where we fix up
return values from mqueue_get_inode.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ipc/mqueue.c

index 14fb6d6..d43c30f 100644 (file)
@@ -115,69 +115,70 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
        struct inode *inode;
 
        inode = new_inode(sb);
-       if (inode) {
-               inode->i_ino = get_next_ino();
-               inode->i_mode = mode;
-               inode->i_uid = current_fsuid();
-               inode->i_gid = current_fsgid();
-               inode->i_mtime = inode->i_ctime = inode->i_atime =
-                               CURRENT_TIME;
+       if (!inode)
+               goto err;
 
-               if (S_ISREG(mode)) {
-                       struct mqueue_inode_info *info;
-                       struct task_struct *p = current;
-                       unsigned long mq_bytes, mq_msg_tblsz;
-
-                       inode->i_fop = &mqueue_file_operations;
-                       inode->i_size = FILENT_SIZE;
-                       /* mqueue specific info */
-                       info = MQUEUE_I(inode);
-                       spin_lock_init(&info->lock);
-                       init_waitqueue_head(&info->wait_q);
-                       INIT_LIST_HEAD(&info->e_wait_q[0].list);
-                       INIT_LIST_HEAD(&info->e_wait_q[1].list);
-                       info->notify_owner = NULL;
-                       info->qsize = 0;
-                       info->user = NULL;      /* set when all is ok */
-                       memset(&info->attr, 0, sizeof(info->attr));
-                       info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
-                       info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
-                       if (attr) {
-                               info->attr.mq_maxmsg = attr->mq_maxmsg;
-                               info->attr.mq_msgsize = attr->mq_msgsize;
-                       }
-                       mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
-                       info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
-                       if (!info->messages)
-                               goto out_inode;
-
-                       mq_bytes = (mq_msg_tblsz +
-                               (info->attr.mq_maxmsg * info->attr.mq_msgsize));
-
-                       spin_lock(&mq_lock);
-                       if (u->mq_bytes + mq_bytes < u->mq_bytes ||
-                           u->mq_bytes + mq_bytes >
-                           task_rlimit(p, RLIMIT_MSGQUEUE)) {
-                               spin_unlock(&mq_lock);
-                               /* mqueue_evict_inode() releases info->messages */
-                               goto out_inode;
-                       }
-                       u->mq_bytes += mq_bytes;
-                       spin_unlock(&mq_lock);
+       inode->i_ino = get_next_ino();
+       inode->i_mode = mode;
+       inode->i_uid = current_fsuid();
+       inode->i_gid = current_fsgid();
+       inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME;
+
+       if (S_ISREG(mode)) {
+               struct mqueue_inode_info *info;
+               struct task_struct *p = current;
+               unsigned long mq_bytes, mq_msg_tblsz;
+
+               inode->i_fop = &mqueue_file_operations;
+               inode->i_size = FILENT_SIZE;
+               /* mqueue specific info */
+               info = MQUEUE_I(inode);
+               spin_lock_init(&info->lock);
+               init_waitqueue_head(&info->wait_q);
+               INIT_LIST_HEAD(&info->e_wait_q[0].list);
+               INIT_LIST_HEAD(&info->e_wait_q[1].list);
+               info->notify_owner = NULL;
+               info->qsize = 0;
+               info->user = NULL;      /* set when all is ok */
+               memset(&info->attr, 0, sizeof(info->attr));
+               info->attr.mq_maxmsg = ipc_ns->mq_msg_max;
+               info->attr.mq_msgsize = ipc_ns->mq_msgsize_max;
+               if (attr) {
+                       info->attr.mq_maxmsg = attr->mq_maxmsg;
+                       info->attr.mq_msgsize = attr->mq_msgsize;
+               }
+               mq_msg_tblsz = info->attr.mq_maxmsg * sizeof(struct msg_msg *);
+               info->messages = kmalloc(mq_msg_tblsz, GFP_KERNEL);
+               if (!info->messages)
+                       goto out_inode;
 
-                       /* all is ok */
-                       info->user = get_uid(u);
-               } else if (S_ISDIR(mode)) {
-                       inc_nlink(inode);
-                       /* Some things misbehave if size == 0 on a directory */
-                       inode->i_size = 2 * DIRENT_SIZE;
-                       inode->i_op = &mqueue_dir_inode_operations;
-                       inode->i_fop = &simple_dir_operations;
+               mq_bytes = (mq_msg_tblsz +
+                       (info->attr.mq_maxmsg * info->attr.mq_msgsize));
+
+               spin_lock(&mq_lock);
+               if (u->mq_bytes + mq_bytes < u->mq_bytes ||
+                   u->mq_bytes + mq_bytes > task_rlimit(p, RLIMIT_MSGQUEUE)) {
+                       spin_unlock(&mq_lock);
+                       /* mqueue_evict_inode() releases info->messages */
+                       goto out_inode;
                }
+               u->mq_bytes += mq_bytes;
+               spin_unlock(&mq_lock);
+
+               /* all is ok */
+               info->user = get_uid(u);
+       } else if (S_ISDIR(mode)) {
+               inc_nlink(inode);
+               /* Some things misbehave if size == 0 on a directory */
+               inode->i_size = 2 * DIRENT_SIZE;
+               inode->i_op = &mqueue_dir_inode_operations;
+               inode->i_fop = &simple_dir_operations;
        }
+
        return inode;
 out_inode:
        iput(inode);
+err:
        return NULL;
 }