filelock: split leases out of struct file_lock

Add a new struct file_lease and move the lease-specific fields from
struct file_lock to it. Convert the appropriate API calls to take
struct file_lease instead, and convert the callers to use them.

There is zero overlap between the lock manager operations for file
locks and the ones for file leases, so split the lease-related
operations off into a new lease_manager_operations struct.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20240131-flsplit-v3-47-c6129007ee8d@kernel.org
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs: use splice_copy_file_range() inline helper

generic_copy_file_range() is just a wrapper around splice_file_range(),
which caps the maximum copy length.

The only caller of splice_file_range(), namely __ceph_copy_file_range()
is already ready to cope with short copy.

Move the length capping into splice_file_range() and replace the exported
symbol generic_copy_file_range() with a simple inline helper.

Suggested-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/linux-fsdevel/20231204083849.GC32438@lst.de/
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231212094440.250945-3-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

fs: Pass argument to fcntl_setlease as int

The interface for fcntl expects the argument passed for the command
F_SETLEASE to be of type int. The current code wrongly treats it as
a long. In order to avoid access to undefined bits, we should explicitly
cast the argument to int.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Anna Schumaker <anna@kernel.org>
Cc: Kevin Brodsky <Kevin.Brodsky@arm.com>
Cc: Vincenzo Frascino <Vincenzo.Frascino@arm.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: David Laight <David.Laight@ACULAB.com>
Cc: Mark Rutland <Mark.Rutland@arm.com>
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-cifs@vger.kernel.org
Cc: linux-nfs@vger.kernel.org
Cc: linux-morello@op-lists.linaro.org
Signed-off-by: Luca Vizzarro <Luca.Vizzarro@arm.com>
Message-Id: <20230414152459.816046-3-Luca.Vizzarro@arm.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

nfs: Provide a splice-read wrapper

Provide a splice_read wrapper for NFS. This locks the inode around
filemap_splice_read() and revalidates the mapping. Splicing from direct
I/O is handled by the caller.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Christoph Hellwig <hch@lst.de>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: Jens Axboe <axboe@kernel.dk>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Anna Schumaker <anna@kernel.org>
cc: linux-nfs@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-block@vger.kernel.org
cc: linux-mm@kvack.org
Link: https://lore.kernel.org/r/20230522135018.2742245-21-dhowells@redhat.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

NFS: make sure open context mode have FMODE_EXEC when file open for exec

Because file f_mode never have FMODE_EXEC, open context mode won't get
FMODE_EXEC from file f_mode. Open context mode only care about FMODE_READ/
FMODE_WRITE/FMODE_EXEC, and all info about open context mode can be convert
from file f_flags, so convert file f_flags to open context mode by
flags_to_mode().

Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2 fix problems with __nfs42_ssc_open

A destination server while doing a COPY shouldn't accept using the
passed in filehandle if its not a regular filehandle.

If alloc_file_pseudo() has failed, we need to decrement a reference
on the newly created inode, otherwise it leaks.

Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Fixes: ec4b092508982 ("NFS: inter ssc open")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Add FMODE_CAN_ODIRECT after successful open of a NFS4.x file

Commit a2ad63daa88b ("VFS: add FMODE_CAN_ODIRECT file flag")
added the FMODE_CAN_ODIRECT flag for NFSv3 but neglected to add
it for NFSv4.x. This causes direct io on NFSv4.x to fail open
with EINVAL:
mount -o vers=4.2 127.0.0.1:/export /mnt/nfs4
dd if=/dev/zero of=/mnt/nfs4/file.bin bs=128k count=1 oflag=direct
dd: failed to open '/mnt/nfs4/file.bin': Invalid argument
dd of=/dev/null if=/mnt/nfs4/file.bin bs=128k count=1 iflag=direct
dd: failed to open '/mnt/dir1/file1.bin': Invalid argument

Fixes: a2ad63daa88b ("VFS: add FMODE_CAN_ODIRECT file flag")
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

m->mnt_root->d_inode->i_sb is a weird way to spell m->mnt_sb...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFSv4: fix open failure with O_ACCMODE flag

open() with O_ACCMODE|O_DIRECT flags secondly will fail.

Reproducer:
1. mount -t nfs -o vers=4.2 $server_ip:/ /mnt/
2. fd = open("/mnt/file", O_ACCMODE|O_DIRECT|O_CREAT)
3. close(fd)
4. fd = open("/mnt/file", O_ACCMODE|O_DIRECT)

Server nfsd4_decode_share_access() will fail with error nfserr_bad_xdr when
client use incorrect share access mode of 0.

Fix this by using NFS4_SHARE_ACCESS_BOTH share access mode in client,
just like firstly opening.

Fixes: ce4ef7c0a8a05 ("NFS: Split out NFS v4 file operations")
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

Revert "NFSv4: Handle the special Linux file open access mode"

This reverts commit 44942b4e457beda00981f616402a1a791e8c616e.

After secondly opening a file with O_ACCMODE|O_DIRECT flags,
nfs4_valid_open_stateid() will dereference NULL nfs4_state when lseek().

Reproducer:
1. mount -t nfs -o vers=4.2 $server_ip:/ /mnt/
2. fd = open("/mnt/file", O_ACCMODE|O_DIRECT|O_CREAT)
3. close(fd)
4. fd = open("/mnt/file", O_ACCMODE|O_DIRECT)
5. lseek(fd)

Reported-by: Lyu Tao <tao.lyu@epfl.ch>
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2/copyoffload: Convert GFP_NOFS to GFP_KERNEL

There doesn't seem to be any reason why the copy offload code can't use
GFP_KERNEL. It can't get called by direct reclaim.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: simplify check for freeing cn_resp

nfs42_files_from_same_server() is called to check if freeing
cn_resp is required, just do the free.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label argument from nfs_fhget()

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Remove the nfs4_label from the nfs4_getattr_res

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: alloc_file_pseudo() takes an open flag, not an f_mode

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: Don't allocate nfs_fattr on the stack in __nfs42_ssc_open()

The preferred behaviour is always to allocate struct nfs_fattr from the
slab.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: remove restriction of copy size for inter-server copy.

Currently inter-server copy is allowed only if the copy size is larger
than (rsize*14) which is the over-head of the mount operation of the
source export. This patch, relying on the delayed unmount feature,
removes this restriction since the mount and unmount overhead is now
not applicable for every inter-server copy.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4: Add support for application leases underpinned by a delegation

If the NFSv4 client already holds a delegation for a file, then we can
support application leases (i.e. fcntl(fd, F_SETLEASE,...)) because the
underlying delegation guarantees that the file is not being modified on
the server by another client in a way that might conflict with the lease
guarantees.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix v4.0/v4.1 SEEK_DATA return -ENOTSUPP when set NFS_V4_2 config

Since commit bdcc2cd14e4e ("NFSv4.2: handle NFS-specific llseek errors"),
nfs42_proc_llseek would return -EOPNOTSUPP rather than -ENOTSUPP when
SEEK_DATA on NFSv4.0/v4.1.

This will lead xfstests generic/285 not run on NFSv4.0/v4.1 when set the
CONFIG_NFS_V4_2, rather than run failed.

Fixes: bdcc2cd14e4e ("NFSv4.2: handle NFS-specific llseek errors")
Cc: <stable.vger.kernel.org> # 4.2
Signed-off-by: Zhang Xiaoxu <zhangxiaoxu5@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: Remove ifdef CONFIG_NFSD from NFSv4.2 client SSC code.

The client SSC code should not depend on any of the CONFIG_NFSD config.
This patch removes all CONFIG_NFSD from NFSv4.2 client SSC code and
simplifies the config of CONFIG_NFS_V4_2_SSC_HELPER, NFSD_V4_2_INTER_SSC.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4_2: SSC helper should use its own config.

Currently NFSv4_2 SSC helper, nfs_ssc, incorrectly uses GRACE_PERIOD
as its config. Fix by adding new config NFS_V4_2_SSC_HELPER which
depends on NFS_V4_2 and is automatically selected when NFSD_V4 is
enabled. Also removed the file name from a comment in nfs_ssc.c.

Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

NFSv4.2: Fix 5 seconds delay when doing inter server copy

Since commit b4868b44c5628 ("NFSv4: Wait for stateid updates after
CLOSE/OPEN_DOWNGRADE"), every inter server copy operation suffers 5
seconds delay regardless of the size of the copy. The delay is from
nfs_set_open_stateid_locked when the check by nfs_stateid_is_sequential
fails because the seqid in both nfs4_state and nfs4_stateid are 0.

Fix __nfs42_ssc_open to delay setting of NFS_OPEN_STATE in nfs4_state,
until after the call to update_open_stateid, to indicate this is the 1st
open. This fix is part of a 2 patches, the other patch is the fix in the
source server to return the stateid for COPY_NOTIFY request with seqid 1
instead of 0.

Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy")
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.2: Fix 5 seconds delay when doing inter server copy

Since commit b4868b44c5628 ("NFSv4: Wait for stateid updates after
CLOSE/OPEN_DOWNGRADE"), every inter server copy operation suffers 5
seconds delay regardless of the size of the copy. The delay is from
nfs_set_open_stateid_locked when the check by nfs_stateid_is_sequential
fails because the seqid in both nfs4_state and nfs4_stateid are 0.

Fix __nfs42_ssc_open to delay setting of NFS_OPEN_STATE in nfs4_state,
until after the call to update_open_stateid, to indicate this is the 1st
open. This fix is part of a 2 patches, the other patch is the fix in the
source server to return the stateid for COPY_NOTIFY request with seqid 1
instead of 0.

Fixes: ce0887ac96d3 ("NFSD add nfs4 inter ssc to nfsd4_copy")
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.2: Fix NFS4ERR_STALE error when doing inter server copy

NFS_FS=y as dependency of CONFIG_NFSD_V4_2_INTER_SSC still have
build errors and some configs with NFSD=m to get NFS4ERR_STALE
error when doing inter server copy.

Added ops table in nfs_common for knfsd to access NFS client modules.

Fixes: 3ac3711adb88 ("NFSD: Fix NFS server build errors")
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

NFS4: Fix oops when copy_file_range is attempted with NFS4.0 source

The following oops is seen during xfstest/565 when the 'test'
(source of the copy) is NFS4.0 and 'scratch' (destination) is NFS4.2
[ 59.692458] run fstests generic/565 at 2020-08-01 05:50:35
[ 60.613588] BUG: kernel NULL pointer dereference, address: 0000000000000008
[ 60.624970] #PF: supervisor read access in kernel mode
[ 60.627671] #PF: error_code(0x0000) - not-present page
[ 60.630347] PGD 0 P4D 0
[ 60.631853] Oops: 0000 [#1] SMP PTI
[ 60.634086] CPU: 6 PID: 2828 Comm: xfs_io Kdump: loaded Not tainted 5.8.0-rc3 #1
[ 60.637676] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
[ 60.639901] RIP: 0010:nfs4_check_serverowner_major_id+0x5/0x30 [nfsv4]
[ 60.642719] Code: 89 ff e8 3e b3 b8 e1 e9 71 fe ff ff 41 bc da d8 ff ff e9 c3 fe ff ff e8 e9 9d 08 e2 66 0f 1f 84 00 00 00 00 00 66 66 66 66 90 <8b> 57 08 31 c0 3b 56 08 75 12 48 83 c6 0c 48 83 c7 0c e8 c4 97 bb
[ 60.652629] RSP: 0018:ffffc265417f7e10 EFLAGS: 00010287
[ 60.655379] RAX: ffffa0664b066400 RBX: 0000000000000000 RCX: 0000000000000001
[ 60.658754] RDX: ffffa066725fb000 RSI: ffffa066725fd000 RDI: 0000000000000000
[ 60.662292] RBP: 0000000000020000 R08: 0000000000020000 R09: 0000000000000000
[ 60.666189] R10: 0000000000000003 R11: 0000000000000000 R12: ffffa06648258d00
[ 60.669914] R13: 0000000000000000 R14: 0000000000000000 R15: ffffa06648258100
[ 60.673645] FS: 00007faa9fb35800(0000) GS:ffffa06677d80000(0000) knlGS:0000000000000000
[ 60.677698] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 60.680773] CR2: 0000000000000008 CR3: 0000000203f14000 CR4: 00000000000406e0
[ 60.684476] Call Trace:
[ 60.685809] nfs4_copy_file_range+0xfc/0x230 [nfsv4]
[ 60.688704] vfs_copy_file_range+0x2ee/0x310
[ 60.691104] __x64_sys_copy_file_range+0xd6/0x210
[ 60.693527] do_syscall_64+0x4d/0x90
[ 60.695512] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 60.698006] RIP: 0033:0x7faa9febc1bd

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

nfs: ensure correct writeback errors are returned on close()

nfs_wb_all() calls filemap_write_and_wait(), which uses
filemap_check_errors() to determine the error to return.
filemap_check_errors() only looks at the mapping->flags and will
therefore only return either -ENOSPC or -EIO. To ensure that the
correct error is returned on close(), nfs{,4}_file_flush() should call
filemap_check_wb_err() which looks at the errseq value in
mapping->wb_err without consuming it.

Fixes: 6fbda89b257f ("NFS: Replace custom error reporting mechanism with
generic one")
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2: error out when relink swapfile

This fixes xfstests generic/356 failure on NFSv4.2.

Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Fix races between open and dentry revalidation

We want to make sure that we revalidate the dentry if and only if
we've done an OPEN by filename.
In order to avoid races with remote changes to the directory on the
server, we want to save the verifier before calling OPEN. The exception
is if the server returned a delegation with our OPEN, as we then
know that the filename can't have changed on the server.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Benjamin Coddington <bcodding@gmail.com>
Tested-by: Benjamin Coddington <bcodding@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Add fs_context support.

Add filesystem context support to NFS, parsing the options in advance and
attaching the information to struct nfs_fs_context. The highlights are:

(*) Merge nfs_mount_info and nfs_clone_mount into nfs_fs_context. This
structure represents NFS's superblock config.

(*) Make use of the VFS's parsing support to split comma-separated lists

(*) Pin the NFS protocol module in the nfs_fs_context.

(*) Attach supplementary error information to fs_context. This has the
downside that these strings must be static and can't be formatted.

(*) Remove the auxiliary file_system_type structs since the information
necessary can be conveyed in the nfs_fs_context struct instead.

(*) Root mounts are made by duplicating the config for the requested mount
so as to have the same parameters. Submounts pick up their parameters
from the parent superblock.

[AV -- retrans is u32, not string]
[SM -- Renamed cfg to ctx in a few functions in an earlier patch]
[SM -- Moved fs_context mount option parsing to an earlier patch]
[SM -- Moved fs_context error logging to a later patch]
[SM -- Fixed printks in nfs4_try_get_tree() and nfs4_get_referral_tree()]
[SM -- Added is_remount_fc() helper]
[SM -- Deferred some refactoring to a later patch]
[SM -- Fixed referral mounts, which were broken in the original patch]
[SM -- Fixed leak of nfs_fattr when fs_context is freed]

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.2 fix memory leak in nfs42_ssc_open

Static analysis with Coverity detected a memory leak

Reported-by: Colin King <colin.king@canonical.com>
Fixes: ec4b09250898 ("NFS: inter ssc open")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2 fix kfree in __nfs42_copy_file_range

This is triggering problems with static analysis with Coverity

Reported-by: Colin King <colin.king@netapp.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: remove duplicated include from nfs4file.c

Remove duplicated include.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFS: replace cross device check in copy_file_range

Add a check to disallow cross file systems copy offload, both
files are expected to be of NFS4.2+ type.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

NFS based on file size issue sync copy or fallback to generic copy offload

For small file sizes, it make sense to issue a synchronous copy (and
save an RPC callback operation). Also, for the inter copy offload,
copy len must be larger than the cost of doing a mount between the
destination and source server (14RPCs are sent during 4.x mount).

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

NFS: handle source server reboot

When the source server reboots after a server-to-server copy was
issued, we need to retry the copy from COPY_NOTIFY. We need to
detect that the source server rebooted and there is a copy waiting
on a destination server and wake it up.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

NFS: skip recovery of copy open on dest server

Mark the open created for the source file on the destination
server. Then if this open is going thru a recovery, then fail
the recovery as we don't need to be recoving a "fake" open.
We need to fail the ongoing READs and vfs_copy_file_range().

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

NFS: inter ssc open

NFSv4.2 inter server to server copy requires the destination server to
READ the data from the source server using the provided stateid and
file handle.

Given an NFSv4 stateid and filehandle from the COPY operaion, provide the
destination server with an NFS client function to create a struct file
suitable for the destiniation server to READ the data to be copied.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Andy Adamson <andros@netapp.com>

NFS: add ca_source_server<> to COPY

Support only one source server address: the same address that
the client and source server use.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

NFS: add COPY_NOTIFY operation

Try using the delegation stateid, then the open stateid.

Only NL4_NETATTR, No support for NL4_NAME and NL4_URL.
Allow only one source server address to be returned for now.

To distinguish between same server copy offload ("intra") and
a copy between different server ("inter"), do a check of server
owner identity and also make sure server is capable of doing
a copy offload.

Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>

NFSv4: Fix return values for nfs4_file_open()

Currently, we are translating RPC level errors such as timeouts,
as well as interrupts etc into EOPENSTALE, which forces a single
replay of the open attempt. What we actually want to do is
force the replay only in the cases where the returned error
indicates that the file may have changed on the server.

So the fix is to spell out the exact set of errors where we want
to return EOPENSTALE.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

nfs: disable client side deduplication

The NFS protocol doesn't support deduplication, so turn it off again.

Fixes: ce96e888fe48e ("Fix nfs4.2 return -EINVAL when do dedupe operation")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4: Handle the special Linux file open access mode

According to the open() manpage, Linux reserves the access mode 3
to mean "check for read and write permission on the file and return
a file descriptor that can't be used for reading or writing."

Currently, the NFSv4 code will ask the server to open the file,
and will use an incorrect share access mode of 0. Since it has
an incorrect share access mode, the client later forgets to send
a corresponding close, meaning it can leak stateids on the server.

Fixes: ce4ef7c0a8a05 ("NFS: Split out NFS v4 file operations")
Cc: stable@vger.kernel.org # 3.6+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

vfs: allow copy_file_range to copy across devices

We want to enable cross-filesystem copy_file_range functionality
where possible, so push the "same superblock only" checks down to
the individual filesystem callouts so they can make their own
decisions about cross-superblock copy offload and fallack to
generic_copy_file_range() for cross-superblock copy.

[Amir] We do not call ->remap_file_range() in case the files are not
on the same sb and do not call ->copy_file_range() in case the files
do not belong to the same filesystem driver.

This changes behavior of the copy_file_range(2) syscall, which will
now allow cross filesystem in-kernel copy. CIFS already supports
cross-superblock copy, between two shares to the same server. This
functionality will now be available via the copy_file_range(2) syscall.

Cc: Steve French <stfrench@microsoft.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

vfs: no fallback for ->copy_file_range

Now that we have generic_copy_file_range(), remove it as a fallback
case when offloads fail. This puts the responsibility for executing
fallbacks on the filesystems that implement ->copy_file_range and
allows us to add operational validity checks to
generic_copy_file_range().

Rework vfs_copy_file_range() to call a new do_copy_file_range()
helper to execute the copying callout, and move calls to
generic_file_copy_range() into filesystem methods where they
currently return failures.

[Amir] overlayfs is not responsible of executing the fallback.
It is the responsibility of the underlying filesystem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Fix nfs4.2 return -EINVAL when do dedupe operation

dedupe_file_range operations is combiled into remap_file_range.
But in nfs42_remap_file_range, it's skiped for dedupe operations.
Before this patch:
# dd if=/dev/zero of=nfs/file bs=1M count=1
# xfs_io -c "dedupe nfs/file 4k 64k 4k" nfs/file
XFS_IOC_FILE_EXTENT_SAME: Invalid argument
After this patch:
# dd if=/dev/zero of=nfs/file bs=1M count=1
# xfs_io -c "dedupe nfs/file 4k 64k 4k" nfs/file
deduped 4096/4096 bytes at offset 65536
4 KiB, 1 ops; 0.0046 sec (865.988 KiB/sec and 216.4971 ops/sec)

Signed-off-by: Xiaoli Feng <fengxiaoli0714@gmail.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Don't inadvertently clear writeback errors

vfs_fsync() has the side effect of clearing unreported writeback errors,
so we need to make sure that we do not abuse it in situations where
applications might not normally expect us to report those errors.

The solution is to replace calls to vfs_fsync() with calls to nfs_wb_all().

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFSv4.1 fix incorrect return value in copy_file_range

According to the NFSv4.2 spec if the input and output file is the
same file, operation should fail with EINVAL. However, linux
copy_file_range() system call has no such restrictions. Therefore,
in such case let's return EOPNOTSUPP and allow VFS to fallback
to doing do_splice_direct(). Also when copy_file_range is called
on an NFSv4.0 or 4.1 mount (ie., a server that doesn't support
COPY functionality), we also need to return EOPNOTSUPP and
fallback to a regular copy.

Fixes xfstest generic/075, generic/091, generic/112, generic/263
for all NFSv4.x versions.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

NFSv4.2 fix unnecessary retry in nfs4_copy_file_range

Currently nfs42_proc_copy_file_range() can not return EAGAIN.

Fixes: e4648aa4f98a ("NFS recover from destination server reboot for copies")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

vfs: make remap_file_range functions take and return bytes completed

Change the remap_file_range functions to take a number of bytes to
operate upon and return the number of bytes they operated on. This is a
requirement for allowing fs implementations to return short clone/dedupe
results to the user, which will enable us to obey resource limits in a
graceful manner.

A subsequent patch will enable copy_file_range to signal to the
->clone_file_range implementation that it can handle a short length,
which will be returned in the function's return value. For now the
short return is not implemented anywhere so the behavior won't change --
either copy_file_range manages to clone the entire range or it tries an
alternative.

Neither clone ioctl can take advantage of this, alas.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

vfs: combine the clone and dedupe into a single remap_file_range

Combine the clone_file_range and dedupe_file_range operations into a
single remap_file_range file operation dispatch since they're
fundamentally the same operation. The differences between the two can
be made in the prep functions.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>

NFS recover from destination server reboot for copies

Mark the destination state to indicate a server-side copy is
happening. On detecting a reboot and recovering open state check
if any state is engaged in a server-side copy, if so, find the
copy and mark it and then signal the waiting thread. Upon wakeup,
if copy was marked then propage EAGAIN to the nfsd_copy_file_range
and restart the copy from scratch.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

NFS: Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Warning level 2 was used: -Wimplicit-fallthrough=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

nfs4file: get rid of pointless include of btrfs.h

should've been killed by "vfs: pull btrfs clone API to vfs layer"...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.

For non */uapi/* files that summary was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139

and resulted in the first patch in this series.

If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:

SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930

and resulted in the second patch in this series.

- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:

SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1

and that resulted in the third patch in this series.

- when the two scanners agreed on the detected license(s), that became
the concluded license(s).

- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.

- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).

- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.

- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct

This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

NFSv4: add flock_owner to open context

An open file description (struct file) in a given process can be
associated with two different lock owners.

It can have a Posix lock owner which will be different in each process
that has a fd on the file.
It can have a Flock owner which will be the same in all processes.

When searching for a lock stateid to use, we need to consider both of these
owners

So add a new "flock_owner" to the "nfs_open_context" (of which there
is one for each open file description).

This flock_owner does not need to be reference-counted as there is a
1-1 relation between 'struct file' and nfs open contexts,
and it will never be part of a list of contexts. So there is no need
for a 'flock_context' - just the owner is enough.

The io_count included in the (Posix) lock_context provides no
guarantee that all read-aheads that could use the state have
completed, so not supporting it for flock locks in not a serious
problem. Synchronization between flock and read-ahead can be added
later if needed.

When creating an open_context for a non-openning create call, we don't have
a 'struct file' to pass in, so the lock context gets initialized with
a NULL owner, but this will never be used.

The flock_owner is not used at all in this patch, that will come later.

Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

switch generic_file_splice_read() to use of ->read_iter()

... and kill the ->splice_read() instances that can be switched to it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFSv4: Revert "Truncating file opens should also sync O_DIRECT writes"

We're not holding any locks, so both nfs_wb_all() and inode_dio_wait()
are unenforcible and have livelock potential. Just limit ourselves to
flushing out the data.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4.2: Fix writeback races in nfs4_copy_file_range

We need to ensure that any writes to the destination file are serialised
with the copy, meaning that the writeback has to occur under the inode lock.

Also relax the writeback requirement on the source, and rely on the
stateid checking to tell us if the source rebooted. Add the helper
nfs_filemap_write_and_wait_range() to call pnfs_sync_inode() as
is appropriate for pNFS servers that may need a layoutcommit.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Add COPY nfs operation

This adds the copy_range file_ops function pointer used by the
sys_copy_range() function call. This patch only implements sync copies,
so if an async copy happens we decode the stateid and ignore it.

Signed-off-by: Anna Schumaker <bjschuma@netapp.com>

nfs: use file_dentry()

NFS may be used as lower layer of overlayfs and accessing f_path.dentry can
lead to a crash.

Fix by replacing direct access of file->f_path.dentry with the
file_dentry() accessor, which will always return a native object.

Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: <stable@vger.kernel.org> # v4.2
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>

nfs: remove nfs4_file_fsync

The only difference to nfs_file_fsync is the call to pnfs_sync_inode. But
pnfs_sync_inode is just an inline that calls a pNFS layout driver method
if CONFIG_PNFS is designed, and thus can be called just fine from the core
NFS module.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

wrappers for ->i_mutex access

parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).

Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFSv4: Fix a compile warning about no prototype for nfs4_ioctl()

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

vfs: pull btrfs clone API to vfs layer

The btrfs clone ioctls are now adopted by other file systems, with NFS
and CIFS already having support for them, and XFS being under active
development. To avoid growth of various slightly incompatible
implementations, add one to the VFS. Note that clones are different from
file copies in several ways:

- they are atomic vs other writers
- they support whole file clones
- they support 64-bit legth clones
- they do not allow partial success (aka short writes)
- clones are expected to be a fast metadata operation

Because of that it would be rather cumbersome to try to piggyback them on
top of the recent clone_file_range infrastructure. The converse isn't
true and the clone_file_range system call could try clone file range as
a first attempt to copy, something that further patches will enable.

Based on earlier work from Peng Tao.

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

nfs: reduce the amount of ifdefs for v4.2 in nfs4file.c

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs: use btrfs ioctl defintions for clone

The NFS CLONE_RANGE defintion was wrong and thus never worked. Fix this
by simply using the btrfs ioctl defintion.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs: allow intra-file CLONE

Originally CLONE didn't allow for intra-file clones, but we recently
updated the spec to support this feature which is also supported by
local Linux file systems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs: offer native ioctls even if CONFIG_COMPAT is set

Without this for example 64-bit binaries on typical amd64 distributions
would not be able to use ioctls on NFS. For now this only affects clones.
Additionally ->compat_ioctl is defined even for non-compat builds, so
get rid of the pointless ifdef.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Fix an 'unused variable' complaint when #ifndef CONFIG_NFS_V4_2

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs42: add NFS_IOC_CLONE_RANGE ioctl

It follows btrfs BTRFS_IOC_CLONE_RANGE lead on ioctl number and
arguments.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs42: respect clone_blksize

draft-ietf-nfsv4-minorversion2-38.txt says:
Both cl_src_offset and
cl_dst_offset must be aligned to the clone block size Section 12.2.1.
The number of bytes to be cloned must be a multiple of the clone
block size, except in the case in which cl_src_offset plus the number
of bytes to be cloned is equal to the source file size.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs42: add NFS_IOC_CLONE ioctl

It can be called by user space to CLONE two files.
Follow btrfs lead and define NFS_IOC_CLONE same as BTRFS_IOC_CLONE.
Thus we don't mess up userspace with too many ioctls.

Signed-off-by: Peng Tao <tao.peng@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Respect the server imposed limit on how many changes we may cache

The NFSv4 delegation spec allows the server to tell a client to limit how
much data it cache after the file is closed. In return, the server
guarantees enough free space to avoid ENOSPC situations, etc.
Prior to this patch, we assumed we could always cache aggressively after
close. Unfortunately, this causes problems with servers that set the
limit to 0 and therefore do not offer any ENOSPC guarantees.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Make opened as optional argument in _nfs4_do_open

Check opened, only update it when non-NULL.
It's not needs define an unused value for the opened
when calling _nfs4_do_open.

v3, same as v2.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs: verify open flags before allowing open

Commit 9597c13b forbade opens with O_APPEND|O_DIRECT for NFSv4:

nfs: verify open flags before allowing an atomic open

Currently, you can open a NFSv4 file with O_APPEND|O_DIRECT, but cannot
fcntl(F_SETFL,...) with those flags. This flag combination is explicitly
forbidden on NFSv3 opens, and it seems like it should also be on NFSv4.

However, you can still open a file with O_DIRECT|O_APPEND if there exists a
cached dentry for the file because nfs4_file_open() is used instead of
nfs_atomic_open() and the check is bypassed. Add the check in
nfs4_file_open() as well.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Reduce time spent holding the i_mutex during fallocate()

At the very least, we should not be taking the i_mutex until after
checking if the server even supports ALLOCATE or DEALLOCATE, allowing
v4.0 or v4.1 to exit without potentially waiting on a lock.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Don't zap caches on fallocate()

This patch adds a GETATTR to the end of ALLOCATE and DEALLOCATE
operations so we can set the updated inode size and change attribute
directly. DEALLOCATE will still need to release pagecache pages, so
nfs42_proc_deallocate() now calls truncate_pagecache_range() before
contacting the server.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

VFS: normal filesystems (and lustre): d_inode() annotations

that's the bulk of filesystem drivers dealing with inodes of their own

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

make new_sync_{read,write}() static

All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFSv4.1/pnfs: Separate out metadata and data consistency for pNFS

The LAYOUTCOMMIT operation means different things to different layout types.
For blocks and objects, it is both a data and metadata consistency operation.
For files and flexfiles, it is only a metadata consistency operation.

This patch separates out the 2 cases, allowing the files/flexfiles layout
drivers to optimise away the data consistency calls to layoutcommit.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4.1/pnfs: Ensure that writes respect the O_SYNC flag when doing O_DIRECT

If the caller does not specify the O_SYNC flag, then it is legitimate
to return from O_DIRECT without doing a pNFS layoutcommit operation.
However if the file is opened O_DIRECT|O_SYNC then we'd better get it
right.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Truncating file opens should also sync O_DIRECT writes

We don't just want to sync out buffered writes, but also O_DIRECT ones.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFSv4: Allow tracing of NFSv4 fsync calls

I appear to have missed this when adding the ftrace probes.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs: Add DEALLOCATE support

This patch adds support for using the NFS v4.2 operation DEALLOCATE to
punch holes in a file.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs: Add ALLOCATE support

This patch adds support for using the NFS v4.2 operation ALLOCATE to
preallocate data in a file.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

NFS: Implement SEEK

The SEEK operation is used when an application makes an lseek call with
either the SEEK_HOLE or SEEK_DATA flags set. I fall back on
nfs_file_llseek() if the server does not have SEEK support.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

locks: consolidate "nolease" routines

GFS2 and NFS have setlease routines that always just return -EINVAL.
Turn that into a generic routine that can live in fs/libfs.c.

Cc: <linux-nfs@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: <cluster-devel@redhat.com>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

nfs: switch to iter_splice_write_file()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

nfs: commit layouts in fdatasync

"fdatasync() is similar to fsync(), but does not flush modified metadata
unless that metadata is needed in order to allow a subsequent data
retrieval to be correctly handled."

We absolutely need to commit the layouts to be able to retrieve the data
in case either the client, the server or the storage subsystem go down.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

nfs: switch to ->write_iter()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

nfs: switch to ->read_iter()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

nfs: use %p[dD] instead of open-coded (and often racy) equivalents

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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

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: [<ffffffff812a1903>] __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:[<ffffffff812a1903>] __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:
[<ffffffff81365a72>] __nfs_fscache_invalidate_page+0x42/0x70
[<ffffffff813553d5>] nfs_invalidate_page+0x75/0x90
[<ffffffff811b8f5e>] truncate_inode_page+0x8e/0x90
[<ffffffff811b90ad>] truncate_inode_pages_range.part.12+0x14d/0x620
[<ffffffff81d6387d>] ? __mutex_lock_slowpath+0x1fd/0x2e0
[<ffffffff811b95d3>] truncate_inode_pages_range+0x53/0x70
[<ffffffff811b969d>] truncate_inode_pages+0x2d/0x40
[<ffffffff811b96ff>] truncate_pagecache+0x4f/0x70
[<ffffffff81356840>] nfs_setattr_update_inode+0xa0/0x120
[<ffffffff81368de4>] nfs3_proc_setattr+0xc4/0xe0
[<ffffffff81357f78>] nfs_setattr+0xc8/0x150
[<ffffffff8122d95b>] notify_change+0x1cb/0x390
[<ffffffff8120a55b>] do_truncate+0x7b/0xc0
[<ffffffff8121f96c>] do_last+0xa4c/0xfd0
[<ffffffff8121ffbc>] path_openat+0xcc/0x670
[<ffffffff81220a0e>] do_filp_open+0x4e/0xb0
[<ffffffff8120ba1f>] do_sys_open+0x13f/0x2b0
[<ffffffff8126aaf6>] compat_SyS_open+0x36/0x50
[<ffffffff81d7204c>] 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)
<crash>
<--__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 <moseleymark@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>

NFSv4: Honour the 'opened' parameter in the atomic_open() filesystem method

Determine if we've created a new file by examining the directory change
attribute and/or the O_EXCL flag.

This fixes a regression when doing a non-exclusive create of a new file.
If the FILE_CREATED flag is not set, the atomic_open() command will
perform full file access permissions checks instead of just checking
for MAY_OPEN.

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

NFSv4: Move dentry instantiation into the NFSv4-specific atomic open code

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

new helper: file_inode(file)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

NFS4: Open files for fscaching

nfs4_file_open() should open files for fscaching.

Signed-off-by: David Howells <dhowells@redhat.com>

NFSv4: Get rid of unnecessary BUG_ON()s

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

NFS: Write the entire file if a server reboot occurs during fsync()

This is to ensure that we don't clear the NFS_CONTEXT_RESEND_WRITES
flag while there are still writes that haven't been resent.

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

NFS: Fix fdatasync/fsync() when confronted with a server reboot

If the server reboots before it can commit the unstable writes to disk,
then nfs_commit_release_pages() will detect this when it compares the
verifier returned by COMMIT to the one returned by WRITE. When this
happens, the client needs to resend those writes in order to guarantee
that they make it to stable storage.

This patch adds a signalling mechanism to notify fsync() that it
needs to retry all writes before it can exit.

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

NFS: fsync() must exit with an error if page writeback failed

We need to ensure that if the call to filemap_write_and_wait_range()
fails, then we report that error back to the application.

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

NFS: Split out NFS v4 file operations

This patch moves the NFS v4 file functions into a new file that is only
compiled when CONFIG_NFS_V4 is enabled.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>