Commit Graph

92 Commits

Author SHA1 Message Date
Trond Myklebust
e93a5e9306 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>
2021-06-13 19:36:28 -04:00
Zhang Xiaoxu
e67afa7ee4 NFSv4: Fix v4.0/v4.1 SEEK_DATA return -ENOTSUPP when set NFS_V4_2 config
Since commit bdcc2cd14e ("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: bdcc2cd14e ("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>
2021-05-27 08:46:19 -04:00
Dai Ngo
d9092b4bb2 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>
2021-04-26 09:29:17 -04:00
Dai Ngo
02591f9feb 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>
2021-01-28 10:55:37 -05:00
Dai Ngo
fe8eb820e3 NFSv4.2: Fix 5 seconds delay when doing inter server copy
Since commit b4868b44c5 ("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: ce0887ac96 ("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>
2020-12-10 16:48:03 -05:00
Linus Torvalds
24717cfbbb The one new feature this time, from Anna Schumaker, is READ_PLUS, which
has the same arguments as READ but allows the server to return an array
 of data and hole extents.
 
 Otherwise it's a lot of cleanup and bugfixes.
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCAAzFiEEYtFWavXG9hZotryuJ5vNeUKO4b4FAl+Q5vsVHGJmaWVsZHNA
 ZmllbGRzZXMub3JnAAoJECebzXlCjuG+DUAP/RlALnXbaoWi8YCcEcc9U1LoQKbD
 CJpDR+FqCOyGwRuzWung/5pvkOO50fGEeAroos+2rF/NgRkQq8EFr9AuBhNOYUFE
 IZhWEOfu/r2ukXyBmcu21HGcWLwPnyJehvjuzTQW2wOHlBi/sdoL5Ap1sVlwVLj5
 EZ5kqJLD+ioG2sufW99Spi55l1Cy+3Y0IhLSWl4ZAE6s8hmFSYAJZFsOeI0Afx57
 USPTDRaeqjyEULkb+f8IhD0eRApOUo4evDn9dwQx+of7HPa1CiygctTKYwA3hnlc
 gXp2KpVA1REaiYVgOPwYlnqBmJ2K9X0wCRzcWy2razqEcVAX/2j7QCe9M2mn4DC8
 xZ2q4SxgXu9yf0qfUSVnDxWmP6ipqq7OmsG0JXTFseGKBdpjJY1qHhyqanVAGvEg
 I+xHnnWfGwNCftwyA3mt3RfSFPsbLlSBIMZxvN4kn8aVlqszGITOQvTdQcLYA6kT
 xWllBf4XKVXMqF0PzerxPDmfzBfhx6b1VPWOIVcu7VLBg3IXoEB2G5xG8MUJiSch
 OUTCt41LUQkerQlnzaZYqwmFdSBfXJefmcE/x/vps4VtQ/fPHX1jQyD7iTu3HfSP
 bRlkKHvNVeTodlBDe/HTPiTA99MShhBJyvtV5wfzIqwjc1cNreed+ePppxn8mxJi
 SmQ2uZk/MpUl7/V0
 =rcOj
 -----END PGP SIGNATURE-----

Merge tag 'nfsd-5.10' of git://linux-nfs.org/~bfields/linux

Pull nfsd updates from Bruce Fields:
 "The one new feature this time, from Anna Schumaker, is READ_PLUS,
  which has the same arguments as READ but allows the server to return
  an array of data and hole extents.

  Otherwise it's a lot of cleanup and bugfixes"

* tag 'nfsd-5.10' of git://linux-nfs.org/~bfields/linux: (43 commits)
  NFSv4.2: Fix NFS4ERR_STALE error when doing inter server copy
  SUNRPC: fix copying of multiple pages in gss_read_proxy_verf()
  sunrpc: raise kernel RPC channel buffer size
  svcrdma: fix bounce buffers for unaligned offsets and multiple pages
  nfsd: remove unneeded break
  net/sunrpc: Fix return value for sysctl sunrpc.transports
  NFSD: Encode a full READ_PLUS reply
  NFSD: Return both a hole and a data segment
  NFSD: Add READ_PLUS hole segment encoding
  NFSD: Add READ_PLUS data support
  NFSD: Hoist status code encoding into XDR encoder functions
  NFSD: Map nfserr_wrongsec outside of nfsd_dispatch
  NFSD: Remove the RETURN_STATUS() macro
  NFSD: Call NFSv2 encoders on error returns
  NFSD: Fix .pc_release method for NFSv2
  NFSD: Remove vestigial typedefs
  NFSD: Refactor nfsd_dispatch() error paths
  NFSD: Clean up nfsd_dispatch() variables
  NFSD: Clean up stale comments in nfsd_dispatch()
  NFSD: Clean up switch statement in nfsd_dispatch()
  ...
2020-10-22 09:44:27 -07:00
Dai Ngo
0cfcd405e7 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: 3ac3711adb ("NFSD: Fix NFS server build errors")
Signed-off-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-10-21 10:31:20 -04:00
Dave Wysochanski
d8a6ad913c 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>
2020-09-21 10:21:10 -04:00
Gustavo A. R. Silva
df561f6688 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>
2020-08-23 17:36:59 -05:00
Scott Mayhew
67dd23f9e6 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: 6fbda89b25 ("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>
2020-08-01 15:37:48 -04:00
Murphy Zhou
f5fdf1243f 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>
2020-03-16 10:14:30 -04:00
Trond Myklebust
cf5b4059ba 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>
2020-02-10 10:50:59 -05:00
David Howells
f2aedb713c 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>
2020-01-15 10:15:17 -05:00
Olga Kornievskaia
f751c54525 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: ec4b092508 ("NFS: inter ssc open")
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-11-18 10:50:41 +01:00
Olga Kornievskaia
66588abe2d 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>
2019-11-18 10:50:30 +01:00
YueHaibing
843aa17a35 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>
2019-11-18 10:47:39 +01:00
Olga Kornievskaia
8dff1df551 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>
2019-10-09 12:06:26 -04:00
Olga Kornievskaia
1275101026 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>
2019-10-09 12:06:22 -04:00
Olga Kornievskaia
0e65a32c8a 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>
2019-10-09 12:06:19 -04:00
Olga Kornievskaia
0b9018b9ca 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>
2019-10-09 12:05:56 -04:00
Olga Kornievskaia
ec4b092508 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>
2019-10-09 12:05:52 -04:00
Olga Kornievskaia
1d38f3f0d7 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>
2019-10-09 12:05:49 -04:00
Olga Kornievskaia
0491567b51 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>
2019-10-09 12:05:45 -04:00
Trond Myklebust
90cf500e33 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>
2019-08-19 08:56:04 -04:00
Linus Torvalds
6860c981b9 NFS client updates for Linux 5.3
Highlights include:
 
 Stable fixes:
 - SUNRPC: Ensure bvecs are re-synced when we re-encode the RPC request
 - Fix an Oops in ff_layout_track_ds_error due to a PTR_ERR() dereference
 - Revert buggy NFS readdirplus optimisation
 - NFSv4: Handle the special Linux file open access mode
 - pnfs: Fix a problem where we gratuitously start doing I/O through the MDS
 
 Features:
 - Allow NFS client to set up multiple TCP connections to the server using
    a new 'nconnect=X' mount option. Queue length is used to balance load.
 - Enhance statistics reporting to report on all transports when using
    multiple connections.
 - Speed up SUNRPC by removing bh-safe spinlocks
 - Add a mechanism to allow NFSv4 to request that containers set a
    unique per-host identifier for when the hostname is not set.
 - Ensure NFSv4 updates the lease_time after a clientid update
 
 Bugfixes and cleanup:
 - Fix use-after-free in rpcrdma_post_recvs
 - Fix a memory leak when nfs_match_client() is interrupted
 - Fix buggy file access checking in NFSv4 open for execute
 - disable unsupported client side deduplication
 - Fix spurious client disconnections
 - Fix occasional RDMA transport deadlock
 - Various RDMA cleanups
 - Various tracepoint fixes
 - Fix the TCP callback channel to guarantee the server can actually send
    the number of callback requests that was negotiated at mount time.
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEESQctxSBg8JpV8KqEZwvnipYKAPIFAl0wz/EACgkQZwvnipYK
 APJUrQ/9FpbWTaI/H0BkBf+/iIDAwuGozldDDRkHpHvykvcbNSFPNk5CA4fV/lCq
 rI0tD9ijj0KJhAjS1RWLb9oXMUm/MDIIcZNvsbOiIfGftzGnxAz022KS2JyV+Xk6
 ul7sCQ8QmbQJzfZk+aFZxl5slS9i5nM+Sa//k5SK3JghOlLuYkW50OlmE6ME8rKP
 sLWD2quLh1J5mjG+B9ml4YWozNi0elFN6ZqdzO/SjIhIG7rn2Hkr0glWcEprdiS7
 qHoF6dIn80oR37YNrcbBtEGqBnMnWkpGAGq2Hgf5I2YtO+xfEgMqqs9FNIcahtQG
 SGa1bnpcys9+fG4fnwzgOgYkvGzKdi/bIYc8lhBowl+76z+6VgjwlwT3wRtnWfO9
 288LZDMMfOSYoDkbA9iGtoQRviIsoGMoeH/r5tZe7U1W35h60NGPVhH9sP9/Gc2s
 Va1xBYK6PaIg+UxeghJmCnNK3zANyEI7AtDVvn0wsJuDcgXO5/PAANenc6/Fl6nf
 U9XB4wmgaM2jN5uqLYT3bJAaAPAXTOayVnnd9oDYb87/31sYM6iwzSPkmm5+qIsi
 0Ftks4PSjpjTTrmUvs3CL+ll3Y9bWUd58qlooGwi6u1DnXDQDzbIoRQBezNFJ+Lc
 MahUVY7w9ATyJFJRvbscO7mRS8qTmr4qP91bAOsYQ0P2Yo02L7k=
 =eR7d
 -----END PGP SIGNATURE-----

Merge tag 'nfs-for-5.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Highlights include:

  Stable fixes:

   - SUNRPC: Ensure bvecs are re-synced when we re-encode the RPC
     request

   - Fix an Oops in ff_layout_track_ds_error due to a PTR_ERR()
     dereference

   - Revert buggy NFS readdirplus optimisation

   - NFSv4: Handle the special Linux file open access mode

   - pnfs: Fix a problem where we gratuitously start doing I/O through
     the MDS

  Features:

   - Allow NFS client to set up multiple TCP connections to the server
     using a new 'nconnect=X' mount option. Queue length is used to
     balance load.

   - Enhance statistics reporting to report on all transports when using
     multiple connections.

   - Speed up SUNRPC by removing bh-safe spinlocks

   - Add a mechanism to allow NFSv4 to request that containers set a
     unique per-host identifier for when the hostname is not set.

   - Ensure NFSv4 updates the lease_time after a clientid update

  Bugfixes and cleanup:

   - Fix use-after-free in rpcrdma_post_recvs

   - Fix a memory leak when nfs_match_client() is interrupted

   - Fix buggy file access checking in NFSv4 open for execute

   - disable unsupported client side deduplication

   - Fix spurious client disconnections

   - Fix occasional RDMA transport deadlock

   - Various RDMA cleanups

   - Various tracepoint fixes

   - Fix the TCP callback channel to guarantee the server can actually
     send the number of callback requests that was negotiated at mount
     time"

* tag 'nfs-for-5.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (68 commits)
  pnfs/flexfiles: Add tracepoints for detecting pnfs fallback to MDS
  pnfs: Fix a problem where we gratuitously start doing I/O through the MDS
  SUNRPC: Optimise transport balancing code
  SUNRPC: Ensure the bvecs are reset when we re-encode the RPC request
  pnfs/flexfiles: Fix PTR_ERR() dereferences in ff_layout_track_ds_error
  NFSv4: Don't use the zero stateid with layoutget
  SUNRPC: Fix up backchannel slot table accounting
  SUNRPC: Fix initialisation of struct rpc_xprt_switch
  SUNRPC: Skip zero-refcount transports
  SUNRPC: Replace division by multiplication in calculation of queue length
  NFSv4: Validate the stateid before applying it to state recovery
  nfs4.0: Refetch lease_time after clientid update
  nfs4: Rename nfs41_setup_state_renewal
  nfs4: Make nfs4_proc_get_lease_time available for nfs4.0
  nfs: Fix copy-and-paste error in debug message
  NFS: Replace 16 seq_printf() calls by seq_puts()
  NFS: Use seq_putc() in nfs_show_stats()
  Revert "NFS: readdirplus optimization by cache mechanism" (memleak)
  SUNRPC: Fix transport accounting when caller specifies an rpc_xprt
  NFS: Record task, client ID, and XID in xdr_status trace points
  ...
2019-07-18 14:32:33 -07:00
Darrick J. Wong
9026b3a973 nfs: disable client side deduplication
The NFS protocol doesn't support deduplication, so turn it off again.

Fixes: ce96e888fe ("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>
2019-07-06 14:54:53 -04:00
Trond Myklebust
44942b4e45 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: ce4ef7c0a8 ("NFS: Split out NFS v4 file operations")
Cc: stable@vger.kernel.org # 3.6+
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2019-07-06 14:54:25 -04:00
Amir Goldstein
5dae222a5f 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>
2019-06-09 10:06:20 -07:00
Dave Chinner
64bf5ff58d 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>
2019-06-09 10:06:19 -07:00
Xiaoli Feng
ce96e888fe 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>
2019-04-25 14:18:15 -04:00
Trond Myklebust
aded8d7b54 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>
2019-04-25 14:18:14 -04:00
Olga Kornievskaia
0769663b4f 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>
2019-04-11 15:23:48 -04:00
Olga Kornievskaia
45ac486ecf NFSv4.2 fix unnecessary retry in nfs4_copy_file_range
Currently nfs42_proc_copy_file_range() can not return EAGAIN.

Fixes: e4648aa4f9 ("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>
2019-01-15 11:24:49 -05:00
Darrick J. Wong
42ec3d4c02 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>
2018-10-30 10:41:49 +11:00
Darrick J. Wong
2e5dfc99f2 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>
2018-10-30 10:41:21 +11:00
Olga Kornievskaia
e4648aa4f9 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>
2018-08-13 17:04:23 -04:00
Gustavo A. R. Silva
01e03bdc74 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>
2018-08-08 16:50:02 -04:00
Al Viro
6db620012f 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>
2017-12-30 00:03:39 -05:00
Greg Kroah-Hartman
b24413180f 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>
2017-11-02 11:10:55 +01:00
NeilBrown
532d4def2f 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>
2016-12-01 17:57:27 -05:00
Al Viro
82c156f853 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>
2016-10-05 18:23:56 -04:00
Trond Myklebust
8b7d9d09b2 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>
2016-07-14 12:42:40 -04:00
Trond Myklebust
837bb1d752 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>
2016-07-05 19:11:07 -04:00
Anna Schumaker
2e72448b07 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>
2016-05-17 15:47:55 -04:00
Linus Torvalds
93061f390f These changes contains a fix for overlayfs interacting with some
(badly behaved) dentry code in various file systems.  These have been
 reviewed by Al and the respective file system mtinainers and are going
 through the ext4 tree for convenience.
 
 This also has a few ext4 encryption bug fixes that were discovered in
 Android testing (yes, we will need to get these sync'ed up with the
 fs/crypto code; I'll take care of that).  It also has some bug fixes
 and a change to ignore the legacy quota options to allow for xfstests
 regression testing of ext4's internal quota feature and to be more
 consistent with how xfs handles this case.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2
 
 iQEcBAABCAAGBQJXBn4aAAoJEPL5WVaVDYGjHWgH/2wXnlQnC2ndJhblBWtPzprz
 OQW4dawdnhxqbTEGUqWe942tZivSb/liu/lF+urCGbWsbgz9jNOCmEAg7JPwlccY
 mjzwDvtVq5U4d2rP+JDWXLy/Gi8XgUclhbQDWFVIIIea6fS7IuFWqoVBR+HPMhra
 9tEygpiy5lNtJA/hqq3/z9x0AywAjwrYR491CuWreo2Uu1aeKg0YZsiDsuAcGioN
 Waa2TgbC/ZZyJuJcPBP8If+VOFAa0ea3F+C/o7Tb9bOqwuz0qSTcaMRgt6eQ2KUt
 P4b9Ecp1XLjJTC7IYOknUOScY3lCyREx/Xya9oGZfFNTSHzbOlLBoplCr3aUpYQ=
 =/HHR
 -----END PGP SIGNATURE-----

Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 bugfixes from Ted Ts'o:
 "These changes contains a fix for overlayfs interacting with some
  (badly behaved) dentry code in various file systems.  These have been
  reviewed by Al and the respective file system mtinainers and are going
  through the ext4 tree for convenience.

  This also has a few ext4 encryption bug fixes that were discovered in
  Android testing (yes, we will need to get these sync'ed up with the
  fs/crypto code; I'll take care of that).  It also has some bug fixes
  and a change to ignore the legacy quota options to allow for xfstests
  regression testing of ext4's internal quota feature and to be more
  consistent with how xfs handles this case"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: ignore quota mount options if the quota feature is enabled
  ext4 crypto: fix some error handling
  ext4: avoid calling dquot_get_next_id() if quota is not enabled
  ext4: retry block allocation for failed DIO and DAX writes
  ext4: add lockdep annotations for i_data_sem
  ext4: allow readdir()'s of large empty directories to be interrupted
  btrfs: fix crash/invalid memory access on fsync when using overlayfs
  ext4 crypto: use dget_parent() in ext4_d_revalidate()
  ext4: use file_dentry()
  ext4: use dget_parent() in ext4_file_open()
  nfs: use file_dentry()
  fs: add file_dentry()
  ext4 crypto: don't let data integrity writebacks fail with ENOMEM
  ext4: check if in-inode xattr is corrupted in ext4_expand_extra_isize_ea()
2016-04-07 17:22:20 -07:00
Miklos Szeredi
be62a1a8fd 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: 4bacc9c923 ("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>
2016-03-26 16:14:39 -04:00
Christoph Hellwig
4ff79bc709 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>
2016-03-16 15:42:43 -04:00
Al Viro
5955102c99 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>
2016-01-22 18:04:28 -05:00
Christoph Hellwig
04b38d6012 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>
2015-12-07 23:11:33 -05:00
Christoph Hellwig
6b7153da2c 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>
2015-11-23 21:53:14 -05:00