linux-stable.git/include/linux/nfs_fs.h, branch v3.13.2

NFS: Enabling v4.2 should not recompile nfsd and lockd

2013-11-19T21:20:40+00:00

When CONFIG_NFS_V4_2 is toggled nfsd and lockd will be recompiled,
instead of only the nfs client.  This patch moves a small amount of code
into the client directory to avoid unnecessary recompiles.

Signed-off-by: Anna Schumaker 
Signed-off-by: Trond Myklebust

NFS: Use i_writecount to control whether to get an fscache cookie in nfs_open()

2013-09-27T17:40:25+00:00

Use i_writecount to control whether to get an fscache cookie in nfs_open() as
NFS does not do write caching yet.  I *think* this is the cause of a problem
encountered by Mark Moseley whereby __fscache_uncache_page() gets a NULL
pointer dereference because cookie->def is NULL:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
IP: [] __fscache_uncache_page+0x23/0x160
PGD 0
Thread overran stack, or stack corrupted
Oops: 0000 [#1] SMP
Modules linked in: ...
CPU: 7 PID: 18993 Comm: php Not tainted 3.11.1 #1
Hardware name: Dell Inc. PowerEdge R420/072XWF, BIOS 1.3.5 08/21/2012
task: ffff8804203460c0 ti: ffff880420346640
RIP: 0010:[] __fscache_uncache_page+0x23/0x160
RSP: 0018:ffff8801053af878 EFLAGS: 00210286
RAX: 0000000000000000 RBX: ffff8800be2f8780 RCX: ffff88022ffae5e8
RDX: 0000000000004c66 RSI: ffffea00055ff440 RDI: ffff8800be2f8780
RBP: ffff8801053af898 R08: 0000000000000001 R09: 0000000000000003
R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00055ff440
R13: 0000000000001000 R14: ffff8800c50be538 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88042fc60000(0063) knlGS:00000000e439c700
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000010 CR3: 0000000001d8f000 CR4: 00000000000607f0
Stack:
...
Call Trace:
[] __nfs_fscache_invalidate_page+0x42/0x70
[] nfs_invalidate_page+0x75/0x90
[] truncate_inode_page+0x8e/0x90
[] truncate_inode_pages_range.part.12+0x14d/0x620
[] ? __mutex_lock_slowpath+0x1fd/0x2e0
[] truncate_inode_pages_range+0x53/0x70
[] truncate_inode_pages+0x2d/0x40
[] truncate_pagecache+0x4f/0x70
[] nfs_setattr_update_inode+0xa0/0x120
[] nfs3_proc_setattr+0xc4/0xe0
[] nfs_setattr+0xc8/0x150
[] notify_change+0x1cb/0x390
[] do_truncate+0x7b/0xc0
[] do_last+0xa4c/0xfd0
[] path_openat+0xcc/0x670
[] do_filp_open+0x4e/0xb0
[] do_sys_open+0x13f/0x2b0
[] compat_SyS_open+0x36/0x50
[] sysenter_dispatch+0x7/0x24

The code at the instruction pointer was disassembled:

> (gdb) disas __fscache_uncache_page
> Dump of assembler code for function __fscache_uncache_page:
> ...
> 0xffffffff812a18ff <+31>: mov 0x48(%rbx),%rax
> 0xffffffff812a1903 <+35>: cmpb $0x0,0x10(%rax)
> 0xffffffff812a1907 <+39>: je 0xffffffff812a19cd <__fscache_uncache_page+237>

These instructions make up:

	ASSERTCMP(cookie->def->type, !=, FSCACHE_COOKIE_TYPE_INDEX);

That cmpb is the faulting instruction (%rax is 0).  So cookie->def is NULL -
which presumably means that the cookie has already been at least partway
through __fscache_relinquish_cookie().

What I think may be happening is something like a three-way race on the same
file:

	PROCESS 1	PROCESS 2	PROCESS 3
	===============	===============	===============
	open(O_TRUNC|O_WRONLY)
			open(O_RDONLY)
					open(O_WRONLY)
	-->nfs_open()
	-->nfs_fscache_set_inode_cookie()
	nfs_fscache_inode_lock()
	nfs_fscache_disable_inode_cookie()
	__fscache_relinquish_cookie()
	nfs_inode->fscache = NULL
	<--nfs_fscache_set_inode_cookie()

			-->nfs_open()
			-->nfs_fscache_set_inode_cookie()
			nfs_fscache_inode_lock()
			nfs_fscache_enable_inode_cookie()
			__fscache_acquire_cookie()
			nfs_inode->fscache = cookie
			<--nfs_fscache_set_inode_cookie()
	<--nfs_open()
	-->nfs_setattr()
	...
	...
	-->nfs_invalidate_page()
	-->__nfs_fscache_invalidate_page()
	cookie = nfsi->fscache
					-->nfs_open()
					-->nfs_fscache_set_inode_cookie()
					nfs_fscache_inode_lock()
					nfs_fscache_disable_inode_cookie()
					-->__fscache_relinquish_cookie()
	-->__fscache_uncache_page(cookie)
	
					<--__fscache_relinquish_cookie()
					nfs_inode->fscache = NULL
					<--nfs_fscache_set_inode_cookie()

What is needed is something to prevent process #2 from reacquiring the cookie
- and I think checking i_writecount should do the trick.

It's also possible to have a two-way race on this if the file is opened
O_TRUNC|O_RDONLY instead.

Reported-by: Mark Moseley 
Signed-off-by: David Howells

NFS: Ensure that rmdir() waits for sillyrenames to complete

2013-09-03T19:26:29+00:00

If an NFS client does

	mkdir("dir");
	fd = open("dir/file");
	unlink("dir/file");
	close(fd);
	rmdir("dir");

then the asynchronous nature of the sillyrename operation means that
we can end up getting EBUSY for the rmdir() in the above test. Fix
that by ensuring that we wait for any in-progress sillyrenames
before sending the rmdir() to the server.

Signed-off-by: Trond Myklebust

NFS: Make nfs_attribute_cache_expired() non-static

2013-07-09T21:17:07+00:00

NFS: Make nfs_attribute_cache_expired() non-static so we can call it from
nfs_readdir().

Signed-off-by: Scott Mayhew 
Signed-off-by: Trond Myklebust

Merge branch 'labeled-nfs' into linux-next

2013-06-28T20:29:51+00:00

* labeled-nfs:
  NFS: Apply v4.1 capabilities to v4.2
  NFS: Add in v4.2 callback operation
  NFS: Make callbacks minor version generic
  Kconfig: Add Kconfig entry for Labeled NFS V4 client
  NFS: Extend NFS xattr handlers to accept the security namespace
  NFS: Client implementation of Labeled-NFS
  NFS: Add label lifecycle management
  NFS:Add labels to client function prototypes
  NFSv4: Extend fattr bitmaps to support all 3 words
  NFSv4: Introduce new label structure
  NFSv4: Add label recommended attribute and NFSv4 flags
  NFSv4.2: Added NFS v4.2 support to the NFS client
  SELinux: Add new labeling type native labels
  LSM: Add flags field to security_sb_set_mnt_opts for in kernel mount data.
  Security: Add Hook to test if the particular xattr is part of a MAC model.
  Security: Add hook to calculate context based on a negative dentry.
  NFS: Add NFSv4.2 protocol constants

Conflicts:
	fs/nfs/nfs4proc.c

NFS: Client implementation of Labeled-NFS

2013-06-08T20:20:16+00:00

This patch implements the client transport and handling support for labeled
NFS. The patch adds two functions to encode and decode the security label
recommended attribute which makes use of the LSM hooks added earlier. It also
adds code to grab the label from the file attribute structures and encode the
label to be sent back to the server.

Acked-by: James Morris 
Signed-off-by: Matthew N. Dodd 
Signed-off-by: Miguel Rodel Felipe 
Signed-off-by: Phua Eu Gene 
Signed-off-by: Khin Mi Mi Aung 
Signed-off-by: Steve Dickson 
Signed-off-by: Trond Myklebust

NFS:Add labels to client function prototypes

2013-06-08T20:20:15+00:00

After looking at all of the nfsv4 operations the label structure has been added
to the prototypes of the functions which can transmit label data.

Signed-off-by: Matthew N. Dodd 
Signed-off-by: Miguel Rodel Felipe 
Signed-off-by: Phua Eu Gene 
Signed-off-by: Khin Mi Mi Aung 
Signed-off-by: Steve Dickson 
Signed-off-by: Trond Myklebust

NFSv4: Introduce new label structure

2013-06-08T20:20:14+00:00

In order to mimic the way that NFSv4 ACLs are implemented we have created a
structure to be used to pass label data up and down the call chain. This patch
adds the new structure and new members to the required NFSv4 call structures.

Signed-off-by: Matthew N. Dodd 
Signed-off-by: Miguel Rodel Felipe 
Signed-off-by: Phua Eu Gene 
Signed-off-by: Khin Mi Mi Aung 
Signed-off-by: Steve Dickson 
Signed-off-by: Trond Myklebust

NFSv4: Close another NFSv4 recovery race

2013-06-06T20:24:44+00:00

State recovery currently relies on being able to find a valid
nfs_open_context in the inode->open_files list.
We therefore need to put the nfs_open_context on the list while
we're still protected by the sp->so_reclaim_seqcount in order
to avoid reboot races.

Signed-off-by: Trond Myklebust

NFS: Add functionality to allow waiting on all outstanding reads to complete

2013-04-09T02:12:33+00:00

This will later allow NFS locking code to wait for readahead to complete
before releasing byte range locks.

Signed-off-by: Trond Myklebust