BMC/Intel-BMC/linux.git/fs/9p/v9fs.c, branch dev

v9fs: fix error handling in v9fs_session_init()

2015-06-08T15:05:06+00:00

On failure, v9fs_session_init() returns with the v9fs_session_info struct partially initialized and expects the caller to invoke v9fs_session_close() to clean it up; however, it doesn't track whether the bdi is initialized or not and curiously invokes bdi_destroy() in both vfs_session_init() failure path too. A. If v9fs_session_init() fails before the bdi is initialized, the follow-up v9fs_session_close() will invoke bdi_destroy() on an uninitialized bdi. B. If v9fs_session_init() fails after the bdi is initialized, bdi_destroy() will be called twice on the same bdi - once in the failure path of v9fs_session_init() and then by v9fs_session_close(). A is broken no matter what. B used to be okay because bdi_destroy() allowed being invoked multiple times on the same bdi, which BTW was broken in its own way - if bdi_destroy() was invoked on an initialiezd but !registered bdi, it'd fail to free percpu counters. Since f0054bb1e1f3 ("writeback: move backing_dev_info->wb_lock and ->worklist into bdi_writeback"), this no longer work - bdi_destroy() on an initialized but not registered bdi works correctly but multiple invocations of bdi_destroy() is no longer allowed. The obvious culprit here is v9fs_session_init()'s odd and broken error behavior. It should simply clean up after itself on failures. This patch makes the following updates to v9fs_session_init(). * @rc -> @retval error return propagation removed. It didn't serve any purpose. Just use @rc. * Move addition to v9fs_sessionlist to the end of the function so that incomplete sessions are not put on the list or iterated and error path doesn't have to worry about it. * Update error handling so that it cleans up after itself. Signed-off-by: Tejun Heo Reported-by: Sasha Levin Signed-off-by: Jens Axboe

fs: introduce f_op->mmap_capabilities for nommu mmap support

2015-01-20T21:02:58+00:00

Since "BDI: Provide backing device capability information [try #3]" the backing_dev_info structure also provides flags for the kind of mmap operation available in a nommu environment, which is entirely unrelated to it's original purpose. Introduce a new nommu-only file operation to provide this information to the nommu mmap code instead. Splitting this from the backing_dev_info structure allows to remove lots of backing_dev_info instance that aren't otherwise needed, and entirely gets rid of the concept of providing a backing_dev_info for a character device. It also removes the need for the mtd_inodefs filesystem. Signed-off-by: Christoph Hellwig Reviewed-by: Tejun Heo Acked-by: Brian Norris Signed-off-by: Jens Axboe

fs/9p/v9fs.c: add __init to v9fs_sysfs_init

2014-06-04T23:53:55+00:00

v9fs_sysfs_init is only called by __init init_v9fs Signed-off-by: Fabian Frederick Cc: Eric Van Hensbergen Cc: Ron Minnich Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

9P: introduction of a new cache=mmap model.

2014-01-10T15:20:51+00:00

- Add cache=mmap option - Make mmap read-write while keeping it as synchronous as possible - Build writeback fid on mmap creation if it is writable Signed-off-by: Dominique Martinet Signed-off-by: Eric Van Hensbergen

9p: don't forget to destroy inode cache if fscache registration fails

2013-09-18T02:31:01+00:00

Signed-off-by: Al Viro

9p: Modify struct v9fs_session_info to use a kuids and kgids

2013-02-12T11:19:33+00:00

Change struct v9fs_session_info and the code that popluates it to use kuids and kgids. When parsing the 9p mount options convert the dfltuid, dflutgid, and the session uid from the current user namespace into kuids and kgids. Modify V9FS_DEFUID and V9FS_DEFGUID to be kuid and kgid values. Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: "Eric W. Biederman"

9p: Modify struct 9p_fid to use a kuid_t not a uid_t

2013-02-12T11:19:32+00:00

Change struct 9p_fid and it's associated functions to use kuid_t's instead of uid_t. Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: "Eric W. Biederman"

9p: Transmit kuid and kgid values

2013-02-12T11:19:30+00:00

Modify the p9_client_rpc format specifiers of every function that directly transmits a uid or a gid from 'd' to 'u' or 'g' as appropriate. Modify those same functions to take kuid_t and kgid_t parameters instead of uid_t and gid_t parameters. Cc: Eric Van Hensbergen Cc: Ron Minnich Cc: Latchesar Ionkov Signed-off-by: Eric W. Biederman

Merge tag 'for-linus-merge-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

2012-10-12T00:59:23+00:00

Pull v9fs update from Eric Van Hensbergen. * tag 'for-linus-merge-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: 9P: Fix race between p9_write_work() and p9_fd_request() 9P: Fix race in p9_write_work() 9P: fix test at the end of p9_write_work() 9P: Fix race in p9_read_work() 9p: don't use __getname/__putname for uname/aname net/9p: Check errno validity fs/9p: avoid debug OOPS when reading a long symlink

fs: push rcu_barrier() from deactivate_locked_super() to filesystems

2012-10-03T01:35:55+00:00

There's no reason to call rcu_barrier() on every deactivate_locked_super(). We only need to make sure that all delayed rcu free inodes are flushed before we destroy related cache. Removing rcu_barrier() from deactivate_locked_super() affects some fast paths. E.g. on my machine exit_group() of a last process in IPC namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time. Signed-off-by: Kirill A. Shutemov Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Al Viro