Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Fix up the issue that array->eof_index needs to be able to be set
even if array->size == 0.

Ensure that we catch all important memory allocation error conditions
and/or kmap() failures.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This reverts commit 80e60639.

This change requires further fixes to ensure that the open doesn't
succeed if the lookup later results in a regular file being created.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Clones an existing reference to inode; caller must already hold one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Also some clean ups.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

By requsting more attributes during a readdir, we can mimic the readdir plus
operation that was in NFSv3.

To test, I ran the command `ls -lU --color=none` on directories with various
numbers of files.  Without readdir plus, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.153s | 0m00.589s | 0m05.601s | 0m56.691s | 9m59.128s
user    | 0m00.007s | 0m00.007s | 0m00.077s | 0m00.703s | 0m06.800s
sys     | 0m00.010s | 0m00.070s | 0m00.633s | 0m06.423s | 1m10.005s
access  | 3         | 1         | 1         | 4         | 31
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 104       | 1,003     | 10,003    | 100,003   | 1,000,003
readdir | 2         | 16        | 158       | 1,575     | 15,749
total   | 111       | 1,021     | 10,163    | 101,583   | 1,015,784

With readdir plus enabled, I see this:

n files |    100    |   1,000   |  10,000   |  100,000  | 1,000,000
--------+-----------+-----------+-----------+-----------+----------
real    | 0m00.115s | 0m00.206s | 0m01.079s | 0m12.521s | 2m07.528s
user    | 0m00.003s | 0m00.003s | 0m00.040s | 0m00.290s | 0m03.296s
sys     | 0m00.007s | 0m00.020s | 0m00.120s | 0m01.357s | 0m17.556s
access  | 3         | 1         | 1         | 1         | 7
getattr | 2         | 1         | 1         | 1         | 1
lookup  | 4         | 3         | 3         | 3         | 3
readdir | 6         | 62        | 630       | 6,300     | 62,993
total   | 15        | 67        | 635       | 6,305     | 63,004

Readdir plus disabled has about a 16x increase in the number of rpc calls and
is 4 - 5 times slower on large directories.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Check if the decoded entry has the eof bit set when returning from xdr_decode
with an error.  If it does, we should set the eof bits in the array before
returning.  This should keep us from looping when we expect more data but the
server doesn't give us anything new.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Check for all errors, not a specific one.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We can use vmapped pages to read more information from the network at once.
This will reduce the number of calls needed to complete a readdir.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
[trondmy: Added #include for linux/vmalloc.h> in fs/nfs/dir.c]
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Convert nfs*xdr.c to use an xdr stream in decode_dirent.  This will prevent a
kernel oops that has been occuring when reading a vmapped page.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch adds readdir plus support to the cache array.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If we're going through the loop in nfs_readdir() more than once, we usually
do not want to restart searching from the beginning of the pages cache.

We only want to do that if the previous search failed...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

This patch adds the readdir cache array and functions to retreive the array
stored on a cache page, clear the array by freeing allocated memory, add an
entry to the array, and search the array for a given cookie.

It then modifies readdir to make use of the new cache array.
With the new cache array method, we no longer need some of this code.

Finally, nfs_llseek_dir() will set file->f_pos to a value greater than 0 and
desc->dir_cookie to zero.  When we see this, readdir needs to find the file
at position file->f_pos from the start of the directory.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If nfs_intent_set_file() returns an error, we usually want to pass that
back up the stack.

Also ensure that nfs_open_revalidate() returns '1' on success.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We may end up removing the current entry from nfs_access_lru_list.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

...since that's where most of the sillyrenaming code lives. A comment
block is added to the beginning as well to clarify how sillyrenaming
works. Also, make nfs_async_unlink static as nfs_sillyrename is the only
caller.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Reviewed-by: NChuck Lever <chuck.lever@oracle.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove all remaining references to the struct nameidata from the low level
NFS layers. Again pass down a partially initialised struct nfs_open_context
when we want to do atomic open+create.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Remove references to 'struct nameidata' from the low-level open_revalidate
code, and replace them with a struct nfs_open_context which will be
correctly initialised upon success.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Start moving the 'struct nameidata' dependent code out of the lower level
NFS code in preparation for the removal of open intents.

Instead of the struct nameidata, we pass down a partially initialised
struct nfs_open_context that will be fully initialised by the atomic open
upon success.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Adam Lackorzynski reports:

with 2.6.35.2 I'm getting this reproducible Oops:

[  110.825396] BUG: unable to handle kernel NULL pointer dereference at
(null)
[  110.828638] IP: [<ffffffff811247b7>] encode_attrs+0x1a/0x2a4
[  110.828638] PGD be89f067 PUD bf18f067 PMD 0
[  110.828638] Oops: 0000 [#1] SMP
[  110.828638] last sysfs file: /sys/class/net/lo/operstate
[  110.828638] CPU 2
[  110.828638] Modules linked in: rtc_cmos rtc_core rtc_lib amd64_edac_mod
i2c_amd756 edac_core i2c_core dm_mirror dm_region_hash dm_log dm_snapshot
sg sr_mod usb_storage ohci_hcd mptspi tg3 mptscsih mptbase usbcore nls_base
[last unloaded: scsi_wait_scan]
[  110.828638]
[  110.828638] Pid: 11264, comm: setchecksum Not tainted 2.6.35.2 #1
[  110.828638] RIP: 0010:[<ffffffff811247b7>]  [<ffffffff811247b7>]
encode_attrs+0x1a/0x2a4
[  110.828638] RSP: 0000:ffff88003bf5b878  EFLAGS: 00010296
[  110.828638] RAX: ffff8800bddb48a8 RBX: ffff88003bf5bb18 RCX:
0000000000000000
[  110.828638] RDX: ffff8800be258800 RSI: 0000000000000000 RDI:
ffff88003bf5b9f8
[  110.828638] RBP: 0000000000000000 R08: ffff8800bddb48a8 R09:
0000000000000004
[  110.828638] R10: 0000000000000003 R11: ffff8800be779000 R12:
ffff8800be258800
[  110.828638] R13: ffff88003bf5b9f8 R14: ffff88003bf5bb20 R15:
ffff8800be258800
[  110.828638] FS:  0000000000000000(0000) GS:ffff880041e00000(0063)
knlGS:00000000556bd6b0
[  110.828638] CS:  0010 DS: 002b ES: 002b CR0: 000000008005003b
[  110.828638] CR2: 0000000000000000 CR3: 00000000be8ef000 CR4:
00000000000006e0
[  110.828638] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[  110.828638] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[  110.828638] Process setchecksum (pid: 11264, threadinfo
ffff88003bf5a000, task ffff88003f232210)
[  110.828638] Stack:
[  110.828638]  0000000000000000 ffff8800bfbcf920 0000000000000000
0000000000000ffe
[  110.828638] <0> 0000000000000000 0000000000000000 0000000000000000
0000000000000000
[  110.828638] <0> 0000000000000000 0000000000000000 0000000000000000
0000000000000000
[  110.828638] Call Trace:
[  110.828638]  [<ffffffff81124c1f>] ? nfs4_xdr_enc_setattr+0x90/0xb4
[  110.828638]  [<ffffffff81371161>] ? call_transmit+0x1c3/0x24a
[  110.828638]  [<ffffffff813774d9>] ? __rpc_execute+0x78/0x22a
[  110.828638]  [<ffffffff81371a91>] ? rpc_run_task+0x21/0x2b
[  110.828638]  [<ffffffff81371b7e>] ? rpc_call_sync+0x3d/0x5d
[  110.828638]  [<ffffffff8111e284>] ? _nfs4_do_setattr+0x11b/0x147
[  110.828638]  [<ffffffff81109466>] ? nfs_init_locked+0x0/0x32
[  110.828638]  [<ffffffff810ac521>] ? ifind+0x4e/0x90
[  110.828638]  [<ffffffff8111e2fb>] ? nfs4_do_setattr+0x4b/0x6e
[  110.828638]  [<ffffffff8111e634>] ? nfs4_do_open+0x291/0x3a6
[  110.828638]  [<ffffffff8111ed81>] ? nfs4_open_revalidate+0x63/0x14a
[  110.828638]  [<ffffffff811056c4>] ? nfs_open_revalidate+0xd7/0x161
[  110.828638]  [<ffffffff810a2de4>] ? do_lookup+0x1a4/0x201
[  110.828638]  [<ffffffff810a4733>] ? link_path_walk+0x6a/0x9d5
[  110.828638]  [<ffffffff810a42b6>] ? do_last+0x17b/0x58e
[  110.828638]  [<ffffffff810a5fbe>] ? do_filp_open+0x1bd/0x56e
[  110.828638]  [<ffffffff811cd5e0>] ? _atomic_dec_and_lock+0x30/0x48
[  110.828638]  [<ffffffff810a9b1b>] ? dput+0x37/0x152
[  110.828638]  [<ffffffff810ae063>] ? alloc_fd+0x69/0x10a
[  110.828638]  [<ffffffff81099f39>] ? do_sys_open+0x56/0x100
[  110.828638]  [<ffffffff81027a22>] ? ia32_sysret+0x0/0x5
[  110.828638] Code: 83 f1 01 e8 f5 ca ff ff 48 83 c4 50 5b 5d 41 5c c3 41
57 41 56 41 55 49 89 fd 41 54 49 89 d4 55 48 89 f5 53 48 81 ec 18 01 00 00
<8b> 06 89 c2 83 e2 08 83 fa 01 19 db 83 e3 f8 83 c3 18 a8 01 8d
[  110.828638] RIP  [<ffffffff811247b7>] encode_attrs+0x1a/0x2a4
[  110.828638]  RSP <ffff88003bf5b878>
[  110.828638] CR2: 0000000000000000
[  112.840396] ---[ end trace 95282e83fd77358f ]---

We need to ensure that the O_EXCL flag is turned off if the user doesn't
set O_CREAT.

Cc: stable@kernel.org
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

To obey NFS cache semantics, the client must verify the cached
attributes when a file is opened.  In most cases this is done by a call to
d_validate as one of the last steps in path_walk.

However for the root of a filesystem, d_validate is only ever called
on the mounted-on filesystem (except when the path ends '.' or '..').
So NFS has no chance to validate the attributes.

So, in nfs_opendir, we revalidate the attributes if the opened
directory is the mountpoint.  This may cause double-validation for "."
and ".." lookups, but that is better than missing regular /path/name
lookups completely.
Signed-off-by: NNeilBrown <neilb@suse.de>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

We don't really support nfs servers that invalidate the file handle after a
rename, so precautions such as flushing out dirty data before renaming the
file are superfluous.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Currently MAY_ACCESS means that filesystems must check the permissions
right then and not rely on cached results or the results of future
operations on the object.  This can be because of a call to sys_access() or
because of a call to chdir() which needs to check search without relying on
any future operations inside that dir.  I plan to use MAY_ACCESS for other
purposes in the security system, so I split the MAY_ACCESS and the
MAY_CHDIR cases.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NStephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

The current shrinker implementation requires the registered callback
to have global state to work from. This makes it difficult to shrink
caches that are not global (e.g. per-filesystem caches). Pass the shrinker
structure to the callback so that users can embed the shrinker structure
in the context the shrinker needs to operate on and get back to it in the
callback via container_of().
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Commit 9c7e7e23 (NFS: Don't call iput() in
nfs_access_cache_shrinker) unintentionally removed the spin unlock for the
inode->i_lock.
Reported-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

iput() can potentially attempt to allocate memory, so we should avoid
calling it in a memory shrinker. Instead, rely on the fact that iput() will
call nfs_access_zap_cache().
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Both iput() and put_rpccred() might allocate memory under certain
circumstances, so make sure that we don't recurse and deadlock...
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

If dentry found stale happens to be a root of disconnected tree, we
can't d_drop() it; its d_hash is actually part of s_anon and d_drop()
would simply hide it from shrink_dcache_for_umount(), leading to
all sorts of fun, including busy inodes on umount and oopsen after
that.

Bug had been there since at least 2006 (commit c636eb already has it),
so it's definitely -stable fodder.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Cc: stable@kernel.org
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix https://bugzilla.kernel.org/show_bug.cgi?id=15789Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

If the NFS_INO_REVAL_FORCED flag is set, that means that we don't yet have
an up to date attribute cache. Even if we hold a delegation, we must
put a GETATTR on the wire.
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Recent change is missing to update "rehash".  With that change, it will
become the cause of adding dentry to hash twice.

This explains the reason of Oops (dereference the freed dentry in
__d_lookup()) on my machine.
Signed-off-by: NOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: NMarvin <marvin24@gmx.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>