linux/fs, branch v3.0.32

wake up s_wait_unfrozen when ->freeze_fs fails

2012-05-21T16:40:05Z

commit e1616300a20c80396109c1cf013ba9a36055a3da upstream. dd slept infinitely when fsfeeze failed because of EIO. To fix this problem, if ->freeze_fs fails, freeze_super() wakes up the tasks waiting for the filesystem to become unfrozen. When s_frozen isn't SB_UNFROZEN in __generic_file_aio_write(), the function sleeps until FITHAW ioctl wakes up s_wait_unfrozen. However, if ->freeze_fs fails, s_frozen is set to SB_UNFROZEN and then freeze_super() returns an error number. In this case, FITHAW ioctl returns EINVAL because s_frozen is already SB_UNFROZEN. There is no way to wake up s_wait_unfrozen, so __generic_file_aio_write() sleeps infinitely. Signed-off-by: Kazuya Mio Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

ext4: fix error handling on inode bitmap corruption

2012-05-21T16:40:04Z

commit acd6ad83517639e8f09a8c5525b1dccd81cd2a10 upstream. When insert_inode_locked() fails in ext4_new_inode() it most likely means inode bitmap got corrupted and we allocated again inode which is already in use. Also doing unlock_new_inode() during error recovery is wrong since the inode does not have I_NEW set. Fix the problem by jumping to fail: (instead of fail_drop:) which declares filesystem error and does not call unlock_new_inode(). Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

ext3: Fix error handling on inode bitmap corruption

2012-05-21T16:40:04Z

commit 1415dd8705394399d59a3df1ab48d149e1e41e77 upstream. When insert_inode_locked() fails in ext3_new_inode() it most likely means inode bitmap got corrupted and we allocated again inode which is already in use. Also doing unlock_new_inode() during error recovery is wrong since inode does not have I_NEW set. Fix the problem by jumping to fail: (instead of fail_drop:) which declares filesystem error and does not call unlock_new_inode(). Reviewed-by: Eric Sandeen Signed-off-by: Jan Kara Signed-off-by: Greg Kroah-Hartman

NFSv4: Revalidate uid/gid after open

2012-05-21T16:40:04Z

This is a shorter (and more appropriate for stable kernels) analog to the following upstream commit: commit 6926afd1925a54a13684ebe05987868890665e2b Author: Trond Myklebust Date: Sat Jan 7 13:22:46 2012 -0500 NFSv4: Save the owner/group name string when doing open ...so that we can do the uid/gid mapping outside the asynchronous RPC context. This fixes a bug in the current NFSv4 atomic open code where the client isn't able to determine what the true uid/gid fields of the file are, (because the asynchronous nature of the OPEN call denies it the ability to do an upcall) and so fills them with default values, marking the inode as needing revalidation. Unfortunately, in some cases, the VFS will do some additional sanity checks on the file, and may override the server's decision to allow the open because it sees the wrong owner/group fields. Signed-off-by: Trond Myklebust Without this patch, logging into two different machines with home directories mounted over NFS4 and then running "vim" and typing ":q" in each reliably produces the following error on the second machine: E137: Viminfo file is not writable: /users/system/rtheys/.viminfo This regression was introduced by 80e52aced138 ("NFSv4: Don't do idmapper upcalls for asynchronous RPC calls", merged during the 2.6.32 cycle) --- after the OPEN call, .viminfo has the default values for st_uid and st_gid (0xfffffffe) cached because we do not want to let rpciod wait for an idmapper upcall to fill them in. The fix used in mainline is to save the owner and group as strings and perform the upcall in _nfs4_proc_open outside the rpciod context, which takes about 600 lines. For stable, we can do something similar with a one-liner: make open check for the stale fields and make a (synchronous) GETATTR call to fill them when needed. Trond dictated the patch, I typed it in, and Rik tested it. Addresses http://bugs.debian.org/659111 and https://bugzilla.redhat.com/789298 Reported-by: Rik Theys Explained-by: David Flyn Signed-off-by: Jonathan Nieder Tested-by: Rik Theys Signed-off-by: Greg Kroah-Hartman

ext4: avoid deadlock on sync-mounted FS w/o journal

2012-05-21T16:40:04Z

commit c1bb05a657fb3d8c6179a4ef7980261fae4521d7 upstream. Processes hang forever on a sync-mounted ext2 file system that is mounted with the ext4 module (default in Fedora 16). I can reproduce this reliably by mounting an ext2 partition with "-o sync" and opening a new file an that partition with vim. vim will hang in "D" state forever. The same happens on ext4 without a journal. I am attaching a small patch here that solves this issue for me. In the sync mounted case without a journal, ext4_handle_dirty_metadata() may call sync_dirty_buffer(), which can't be called with buffer lock held. Also move mb_cache_entry_release inside lock to avoid race fixed previously by 8a2bfdcb ext[34]: EA block reference count racing fix Note too that ext2 fixed this same problem in 2006 with b2f49033 [PATCH] fix deadlock in ext2 Signed-off-by: Martin.Wilck@ts.fujitsu.com [sandeen@redhat.com: move mb_cache_entry_release before unlock, edit commit msg] Signed-off-by: Eric Sandeen Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman

jffs2: Fix lock acquisition order bug in gc path

2012-05-21T16:40:03Z

commit 226bb7df3d22bcf4a1c0fe8206c80cc427498eae upstream. The locking policy is such that the erase_complete_block spinlock is nested within the alloc_sem mutex. This fixes a case in which the acquisition order was erroneously reversed. This issue was caught by the following lockdep splat: ======================================================= [ INFO: possible circular locking dependency detected ] 3.0.5 #1 ------------------------------------------------------- jffs2_gcd_mtd6/299 is trying to acquire lock: (&c->alloc_sem){+.+.+.}, at: [] jffs2_garbage_collect_pass+0x314/0x890 but task is already holding lock: (&(&c->erase_completion_lock)->rlock){+.+...}, at: [] jffs2_garbage_collect_pass+0x308/0x890 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&(&c->erase_completion_lock)->rlock){+.+...}: [] validate_chain+0xe6c/0x10bc [] __lock_acquire+0x54c/0xba4 [] lock_acquire+0xa4/0x114 [] _raw_spin_lock+0x3c/0x4c [] jffs2_garbage_collect_pass+0x4c/0x890 [] jffs2_garbage_collect_thread+0x1b4/0x1cc [] kthread+0x98/0xa0 [] kernel_thread_exit+0x0/0x8 -> #0 (&c->alloc_sem){+.+.+.}: [] print_circular_bug+0x70/0x2c4 [] validate_chain+0x1034/0x10bc [] __lock_acquire+0x54c/0xba4 [] lock_acquire+0xa4/0x114 [] mutex_lock_nested+0x74/0x33c [] jffs2_garbage_collect_pass+0x314/0x890 [] jffs2_garbage_collect_thread+0x1b4/0x1cc [] kthread+0x98/0xa0 [] kernel_thread_exit+0x0/0x8 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&(&c->erase_completion_lock)->rlock); lock(&c->alloc_sem); lock(&(&c->erase_completion_lock)->rlock); lock(&c->alloc_sem); *** DEADLOCK *** 1 lock held by jffs2_gcd_mtd6/299: #0: (&(&c->erase_completion_lock)->rlock){+.+...}, at: [] jffs2_garbage_collect_pass+0x308/0x890 stack backtrace: [] (unwind_backtrace+0x0/0x100) from [] (dump_stack+0x20/0x24) [] (dump_stack+0x20/0x24) from [] (print_circular_bug+0x1c8/0x2c4) [] (print_circular_bug+0x1c8/0x2c4) from [] (validate_chain+0x1034/0x10bc) [] (validate_chain+0x1034/0x10bc) from [] (__lock_acquire+0x54c/0xba4) [] (__lock_acquire+0x54c/0xba4) from [] (lock_acquire+0xa4/0x114) [] (lock_acquire+0xa4/0x114) from [] (mutex_lock_nested+0x74/0x33c) [] (mutex_lock_nested+0x74/0x33c) from [] (jffs2_garbage_collect_pass+0x314/0x890) [] (jffs2_garbage_collect_pass+0x314/0x890) from [] (jffs2_garbage_collect_thread+0x1b4/0x1cc) [] (jffs2_garbage_collect_thread+0x1b4/0x1cc) from [] (kthread+0x98/0xa0) [] (kthread+0x98/0xa0) from [] (kernel_thread_exit+0x0/0x8) This was introduce in '81cfc9f jffs2: Fix serious write stall due to erase'. Signed-off-by: Josh Cartwright Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse Signed-off-by: Greg Kroah-Hartman

hfsplus: Fix potential buffer overflows

2012-05-07T15:56:50Z

commit 6f24f892871acc47b40dd594c63606a17c714f77 upstream. Commit ec81aecb2966 ("hfs: fix a potential buffer overflow") fixed a few potential buffer overflows in the hfs filesystem. But as Timo Warns pointed out, these changes also need to be made on the hfsplus filesystem as well. Reported-by: Timo Warns Acked-by: WANG Cong Cc: Alexey Khoroshilov Cc: Miklos Szeredi Cc: Sage Weil Cc: Eugene Teo Cc: Roman Zippel Cc: Al Viro Cc: Christoph Hellwig Cc: Alexey Dobriyan Cc: Dave Anderson Cc: Andrew Morton Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds

autofs: make the autofsv5 packet file descriptor use a packetized pipe

2012-05-07T15:56:37Z

commit 64f371bc3107e69efce563a3d0f0e6880de0d537 upstream. The autofs packet size has had a very unfortunate size problem on x86: because the alignment of 'u64' differs in 32-bit and 64-bit modes, and because the packet data was not 8-byte aligned, the size of the autofsv5 packet structure differed between 32-bit and 64-bit modes despite looking otherwise identical (300 vs 304 bytes respectively). We first fixed that up by making the 64-bit compat mode know about this problem in commit a32744d4abae ("autofs: work around unhappy compat problem on x86-64"), and that made a 32-bit 'systemd' work happily on a 64-bit kernel because everything then worked the same way as on a 32-bit kernel. But it turned out that 'automount' had actually known and worked around this problem in user space, so fixing the kernel to do the proper 32-bit compatibility handling actually *broke* 32-bit automount on a 64-bit kernel, because it knew that the packet sizes were wrong and expected those incorrect sizes. As a result, we ended up reverting that compatibility mode fix, and thus breaking systemd again, in commit fcbf94b9dedd. With both automount and systemd doing a single read() system call, and verifying that they get *exactly* the size they expect but using different sizes, it seemed that fixing one of them inevitably seemed to break the other. At one point, a patch I seriously considered applying from Michael Tokarev did a "strcmp()" to see if it was automount that was doing the operation. Ugly, ugly. However, a prettier solution exists now thanks to the packetized pipe mode. By marking the communication pipe as being packetized (by simply setting the O_DIRECT flag), we can always just write the bigger packet size, and if user-space does a smaller read, it will just get that partial end result and the extra alignment padding will simply be thrown away. This makes both automount and systemd happy, since they now get the size they asked for, and the kernel side of autofs simply no longer needs to care - it could pad out the packet arbitrarily. Of course, if there is some *other* user of autofs (please, please, please tell me it ain't so - and we haven't heard of any) that tries to read the packets with multiple writes, that other user will now be broken - the whole point of the packetized mode is that one system call gets exactly one packet, and you cannot read a packet in pieces. Tested-by: Michael Tokarev Cc: Alan Cox Cc: David Miller Cc: Ian Kent Cc: Thomas Meyer Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

pipes: add a "packetized pipe" mode for writing

2012-05-07T15:56:36Z

commit 9883035ae7edef3ec62ad215611cb8e17d6a1a5d upstream. The actual internal pipe implementation is already really about individual packets (called "pipe buffers"), and this simply exposes that as a special packetized mode. When we are in the packetized mode (marked by O_DIRECT as suggested by Alan Cox), a write() on a pipe will not merge the new data with previous writes, so each write will get a pipe buffer of its own. The pipe buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn will tell the reader side to break the read at that boundary (and throw away any partial packet contents that do not fit in the read buffer). End result: as long as you do writes less than PIPE_BUF in size (so that the pipe doesn't have to split them up), you can now treat the pipe as a packet interface, where each read() system call will read one packet at a time. You can just use a sufficiently big read buffer (PIPE_BUF is sufficient, since bigger than that doesn't guarantee atomicity anyway), and the return value of the read() will naturally give you the size of the packet. NOTE! We do not support zero-sized packets, and zero-sized reads and writes to a pipe continue to be no-ops. Also note that big packets will currently be split at write time, but that the size at which that happens is not really specified (except that it's bigger than PIPE_BUF). Currently that limit is the system page size, but we might want to explicitly support bigger packets some day. The main user for this is going to be the autofs packet interface, allowing us to stop having to care so deeply about exact packet sizes (which have had bugs with 32/64-bit compatibility modes). But user space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will fail with an EINVAL on kernels that do not support this interface. Tested-by: Michael Tokarev Cc: Alan Cox Cc: David Miller Cc: Ian Kent Cc: Thomas Meyer Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

nfsd: fix error values returned by nfsd4_lockt() when nfsd_open() fails

2012-05-07T15:56:35Z

commit 04da6e9d63427b2d0fd04766712200c250b3278f upstream. nfsd_open() already returns an NFS error value; only vfs_test_lock() result needs to be fed through nfserrno(). Broken by commit 55ef12 (nfsd: Ensure nfsv4 calls the underlying filesystem on LOCKT) three years ago... Signed-off-by: Al Viro Signed-off-by: Jonathan Nieder Signed-off-by: Greg Kroah-Hartman