[158/244] ipc/mqueue.c: refactor failure handling

From: Greg KH
Date: Wed Sep 28 2011 - 19:03:31 EST


3.0-stable review patch. If anyone has any objections, please let us know.

------------------

From: Jiri Slaby <jslaby@xxxxxxx>

commit 04715206c0c2fd4ec5ca77fa51e3a5b41ce71492 upstream.

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@xxxxxxx>
Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
ipc/mqueue.c | 115 +++++++++++++++++++++++++++++------------------------------
1 file changed, 58 insertions(+), 57 deletions(-)

--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -115,69 +115,70 @@ static struct inode *mqueue_get_inode(st
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 (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);
+ if (!inode)
+ goto err;

- /* 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;
+ 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;
+
+ 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;
}



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