Commit Graph

65 Commits

Author SHA1 Message Date
NeilBrown
c0cbe70742 NFSD: add posix ACLs to struct nfsd_attrs
pacl and dpacl pointers are added to struct nfsd_attrs, which requires
that we have an nfsd_attrs_free() function to free them.
Those nfsv4 functions that can set ACLs now set up these pointers
based on the passed in NFSv4 ACL.

nfsd_setattr() sets the acls as appropriate.

Errors are handled as with security labels.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-08-04 10:28:03 -04:00
NeilBrown
d6a97d3f58 NFSD: add security label to struct nfsd_attrs
nfsd_setattr() now sets a security label if provided, and nfsv4 provides
it in the 'open' and 'create' paths and the 'setattr' path.
If setting the label failed (including because the kernel doesn't
support labels), an error field in 'struct nfsd_attrs' is set, and the
caller can respond.  The open/create callers clear
FATTR4_WORD2_SECURITY_LABEL in the returned attr set in this case.
The setattr caller returns the error.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29 20:17:00 -04:00
NeilBrown
93adc1e391 NFSD: set attributes when creating symlinks
The NFS protocol includes attributes when creating symlinks.
Linux does store attributes for symlinks and allows them to be set,
though they are not used for permission checking.

NFSD currently doesn't set standard (struct iattr) attributes when
creating symlinks, but for NFSv4 it does set ACLs and security labels.
This is inconsistent.

To improve consistency, pass the provided attributes into nfsd_symlink()
and call nfsd_create_setattr() to set them.

NOTE: this results in a behaviour change for all NFS versions when the
client sends non-default attributes with a SYMLINK request. With the
Linux client, the only attributes are:
	attr.ia_mode = S_IFLNK | S_IRWXUGO;
	attr.ia_valid = ATTR_MODE;
so the final outcome will be unchanged. Other clients might sent
different attributes, and if they did they probably expect them to be
honoured.

We ignore any error from nfsd_create_setattr().  It isn't really clear
what should be done if a file is successfully created, but the
attributes cannot be set.  NFS doesn't allow partial success to be
reported.  Reporting failure is probably more misleading than reporting
success, so the status is ignored.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29 20:17:00 -04:00
NeilBrown
7fe2a71dda NFSD: introduce struct nfsd_attrs
The attributes that nfsd might want to set on a file include 'struct
iattr' as well as an ACL and security label.
The latter two are passed around quite separately from the first, in
part because they are only needed for NFSv4.  This leads to some
clumsiness in the code, such as the attributes NOT being set in
nfsd_create_setattr().

We need to keep the directory locked until all attributes are set to
ensure the file is never visibile without all its attributes.  This need
combined with the inconsistent handling of attributes leads to more
clumsiness.

As a first step towards tidying this up, introduce 'struct nfsd_attrs'.
This is passed (by reference) to vfs.c functions that work with
attributes, and is assembled by the various nfs*proc functions which
call them.  As yet only iattr is included, but future patches will
expand this.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-07-29 20:17:00 -04:00
Chuck Lever
f4d84c5264 NFSD: Clean up nfsd_open_verified()
Its only caller always passes S_IFREG as the @type parameter. As an
additional clean-up, add a kerneldoc comment.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-20 13:18:25 -04:00
Chuck Lever
1c388f2775 NFSD: Remove do_nfsd_create()
Now that its two callers have their own version-specific instance of
this function, do_nfsd_create() is no longer used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-20 13:18:25 -04:00
Chuck Lever
5f46e950c3 NFSD: Refactor nfsd_create_setattr()
I'd like to move do_nfsd_create() out of vfs.c. Therefore
nfsd_create_setattr() needs to be made publicly visible.

Note that both call sites in vfs.c commit both the new object and
its parent directory, so just combine those common metadata commits
into nfsd_create_setattr().

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-05-20 13:18:24 -04:00
Chuck Lever
5f9a62ff7d NFSD: Remove CONFIG_NFSD_V3
Eventually support for NFSv2 in the Linux NFS server is to be
deprecated and then removed.

However, NFSv2 is the "always supported" version that is available
as soon as CONFIG_NFSD is set.  Before NFSv2 support can be removed,
we need to choose a different "always supported" version.

This patch removes CONFIG_NFSD_V3 so that NFSv3 is always supported,
as NFSv2 is today. When NFSv2 support is removed, NFSv3 will become
the only "always supported" NFS version.

The defconfigs still need to be updated to remove CONFIG_NFSD_V3=y.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2022-03-11 10:25:14 -05:00
Chuck Lever
3f965021c8 NFSD: COMMIT operations must not return NFS?ERR_INVAL
Since, well, forever, the Linux NFS server's nfsd_commit() function
has returned nfserr_inval when the passed-in byte range arguments
were non-sensical.

However, according to RFC 1813 section 3.3.21, NFSv3 COMMIT requests
are permitted to return only the following non-zero status codes:

      NFS3ERR_IO
      NFS3ERR_STALE
      NFS3ERR_BADHANDLE
      NFS3ERR_SERVERFAULT

NFS3ERR_INVAL is not included in that list. Likewise, NFS4ERR_INVAL
is not listed in the COMMIT row of Table 6 in RFC 8881.

RFC 7530 does permit COMMIT to return NFS4ERR_INVAL, but does not
specify when it can or should be used.

Instead of dropping or failing a COMMIT request in a byte range that
is not supported, turn it into a valid request by treating one or
both arguments as zero. Offset zero means start-of-file, count zero
means until-end-of-file, so we only ever extend the commit range.
NFS servers are always allowed to commit more and sooner than
requested.

The range check is no longer bounded by NFS_OFFSET_MAX, but rather
by the value that is returned in the maxfilesize field of the NFSv3
FSINFO procedure or the NFSv4 maxfilesize file attribute.

Note that this change results in a new pynfs failure:

CMT4     st_commit.testCommitOverflow                             : RUNNING
CMT4     st_commit.testCommitOverflow                             : FAILURE
           COMMIT with offset + count overflow should return
           NFS4ERR_INVAL, instead got NFS4_OK

IMO the test is not correct as written: RFC 8881 does not allow the
COMMIT operation to return NFS4ERR_INVAL.

Reported-by: Dan Aloni <dan.aloni@vastdata.com>
Cc: stable@vger.kernel.org
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Bruce Fields <bfields@fieldses.org>
2022-02-09 09:24:23 -05:00
Trond Myklebust
a2f4c3fa4d nfsd: Add a tracepoint for errors in nfsd4_clone_file_range()
Since a clone error commit can cause the boot verifier to change,
we should trace those errors.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
[ cel: Addressed a checkpatch.pl splat in fs/nfsd/vfs.h ]
2022-01-08 14:42:02 -05:00
Chuck Lever
907c38227f NFSD: Update the NFSv3 ACCESS3res encoder to use struct xdr_stream
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2021-03-22 10:18:52 -04:00
Frank van der Linden
32119446bb nfsd: define xattr functions to call into their vfs counterparts
This adds the filehandle based functions for the xattr operations
that call in to the vfs layer to do the actual work.

Signed-off-by: Frank van der Linden <fllinden@amazon.com>
[ cel: address checkpatch.pl complaint ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2020-07-13 17:27:03 -04:00
Trond Myklebust
19e0663ff9 nfsd: Ensure sampling of the write verifier is atomic with the write
When doing an unstable write, we need to ensure that we sample the
write verifier before releasing the lock, and allowing a commit to
the same file to proceed.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:41 -05:00
Trond Myklebust
524ff1af22 nfsd: Ensure sampling of the commit verifier is atomic with the commit
When we have a successful commit, ensure we sample the commit verifier
before releasing the lock.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:41 -05:00
Trond Myklebust
b66ae6dd0c nfsd: Pass the nfsd_file as arguments to nfsd4_clone_file_range()
Needed in order to fix exclusion w.r.t. writes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:40 -05:00
Trond Myklebust
16f8f89410 nfsd: Allow nfsd_vfs_write() to take the nfsd_file as an argument
Needed in order to fix stable writes.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2020-01-22 16:25:40 -05:00
Arnd Bergmann
2a1aa48929 nfsd: pass a 64-bit guardtime to nfsd_setattr()
Guardtime handling in nfs3 differs between 32-bit and 64-bit
architectures, and uses the deprecated time_t type.

Change it to using time64_t, which behaves the same way on
64-bit and 32-bit architectures, treating the number as an
unsigned 32-bit entity with a range of year 1970 to 2106
consistently, and avoiding the y2038 overflow.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-12-19 17:46:08 -05:00
Trond Myklebust
a25e3726b3 nfsd: Ensure CLONE persists data and metadata changes to the target file
The NFSv4.2 CLONE operation has implicit persistence requirements on the
target file, since there is no protocol requirement that the client issue
a separate operation to persist data.
For that reason, we should call vfs_fsync_range() on the destination file
after a successful call to vfs_clone_file_range().

Fixes: ffa0160a10 ("nfsd: implement the NFSv4.2 CLONE operation")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-11-30 14:55:38 -05:00
Trond Myklebust
83a63072c8 nfsd: fix nfs read eof detection
Currently, the knfsd server assumes that a short read indicates an
end of file. That assumption is incorrect. The short read means that
either we've hit the end of file, or we've hit a read error.

In the case of a read error, the client may want to retry (as per the
implementation recommendations in RFC1813 and RFC7530), but currently it
is being told that it hit an eof.

Move the code to detect eof from version specific code into the generic
nfsd read.

Report eof only in the two following cases:
1) read() returns a zero length short read with no error.
2) the offset+length of the read is >= the file size.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-09-23 16:24:08 -04:00
Jeff Layton
501cb1849f nfsd: rip out the raparms cache
The raparms cache was set up in order to ensure that we carry readahead
information forward from one RPC call to the next. In other words, it
was set up because each RPC call was forced to open a struct file, then
close it, causing the loss of readahead information that is normally
cached in that struct file, and used to keep the page cache filled when
a user calls read() multiple times on the same file descriptor.

Now that we cache the struct file, and reuse it for all the I/O calls
to a given file by a given user, we no longer have to keep a separate
readahead cache.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:09:09 -04:00
Jeff Layton
65294c1f2c nfsd: add a new struct file caching facility to nfsd
Currently, NFSv2/3 reads and writes have to open a file, do the read or
write and then close it again for each RPC. This is highly inefficient,
especially when the underlying filesystem has a relatively slow open
routine.

This patch adds a new open file cache to knfsd. Rather than doing an
open for each RPC, the read/write handlers can call into this cache to
see if there is one already there for the correct filehandle and
NFS_MAY_READ/WRITE flags.

If there isn't an entry, then we create a new one and attempt to
perform the open. If there is, then we wait until the entry is fully
instantiated and return it if it is at the end of the wait. If it's
not, then we attempt to take over construction.

Since the main goal is to speed up NFSv2/3 I/O, we don't want to
close these files on last put of these objects. We need to keep them
around for a little while since we never know when the next READ/WRITE
will come in.

Cache entries have a hardcoded 1s timeout, and we have a recurring
workqueue job that walks the cache and purges any entries that have
expired.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: Weston Andros Adamson <dros@primarydata.com>
Signed-off-by: Richard Sharpe <richard.sharpe@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-08-19 11:00:39 -04:00
J. Bruce Fields
0b8f62625d nfsd: allow fh_want_write to be called twice
A fuzzer recently triggered lockdep warnings about potential sb_writers
deadlocks caused by fh_want_write().

Looks like we aren't careful to pair each fh_want_write() with an
fh_drop_write().

It's not normally a problem since fh_put() will call fh_drop_write() for
us.  And was OK for NFSv3 where we'd do one operation that might call
fh_want_write(), and then put the filehandle.

But an NFSv4 protocol fuzzer can do weird things like call unlink twice
in a compound, and then we get into trouble.

I'm a little worried about this approach of just leaving everything to
fh_put().  But I think there are probably a lot of
fh_want_write()/fh_drop_write() imbalances so for now I think we need it
to be more forgiving.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2019-04-24 09:46:35 -04:00
Chuck Lever
87c5942e8f nfsd: Add I/O trace points in the NFSv4 read proc
NFSv4 read compound processing invokes nfsd_splice_read and
nfs_readv directly, so the trace points currently in nfsd_read are
not invoked for NFSv4 reads.

Move the NFSD READ trace points to common helpers so that NFSv4
reads are captured.

Also, record any local I/O error that occurs, the total count of
bytes that were actually returned, and whether splice or vectored
read was used.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2018-04-03 15:08:15 -04:00
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
David Howells
a528d35e8b statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode.  This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included.  The
following have been included:

 (1) Make the fields a consistent size on all arches and make them large.

 (2) Spare space, request flags and information flags are provided for
     future expansion.

 (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
     __s64).

 (4) Creation time: The SMB protocol carries the creation time, which could
     be exported by Samba, which will in turn help CIFS make use of
     FS-Cache as that can be used for coherency data (stx_btime).

     This is also specified in NFSv4 as a recommended attribute and could
     be exported by NFSD [Steve French].

 (5) Lightweight stat: Ask for just those details of interest, and allow a
     netfs (such as NFS) to approximate anything not of interest, possibly
     without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
     Dilger] (AT_STATX_DONT_SYNC).

 (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
     its cached attributes are up to date [Trond Myklebust]
     (AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

 (7) Data version number: Could be used by userspace NFS servers [Aneesh
     Kumar].

     Can also be used to modify fill_post_wcc() in NFSD which retrieves
     i_version directly, but has just called vfs_getattr().  It could get
     it from the kstat struct if it used vfs_xgetattr() instead.

     (There's disagreement on the exact semantics of a single field, since
     not all filesystems do this the same way).

 (8) BSD stat compatibility: Including more fields from the BSD stat such
     as creation time (st_btime) and inode generation number (st_gen)
     [Jeremy Allison, Bernd Schubert].

 (9) Inode generation number: Useful for FUSE and userspace NFS servers
     [Bernd Schubert].

     (This was asked for but later deemed unnecessary with the
     open-by-handle capability available and caused disagreement as to
     whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

     (No particular data were offered, but things like last backup
     timestamp, the data version number and the DOS archive bit would come
     into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
     filesystem can now say it doesn't support a standard stat feature if
     that isn't available, so if, for instance, inode numbers or UIDs don't
     exist or are fabricated locally...

     (This requires a separate system call - I have an fsinfo() call idea
     for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
     struct xstat [Steve French].

     (Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
     granularity of each of the times (NFSv4 time_delta) [Steve French].

     (Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value.  These could be translated to BSD's st_flags.
     Note that the Linux IOC flags are a mess and filesystems such as Ext4
     define flags that aren't in linux/fs.h, so translation in the kernel
     may be a necessity (or, possibly, we provide the filesystem type too).

     (Some attributes are made available in stx_attributes, but the general
     feeling was that the IOC flags were to ext[234]-specific and shouldn't
     be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
     Michael Kerrisk].

     (Deferred, probably to fsinfo.  Finding out if there's an ACL or
     seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

     (A __reserved field has been left in the statx_timestamp struct for
     this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

	int ret = statx(int dfd,
			const char *filename,
			unsigned int flags,
			unsigned int mask,
			struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat().  There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags.  There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

 (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
     respect.

 (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
     its attributes with the server - which might require data writeback to
     occur to get the timestamps correct.

 (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
     network filesystem.  The resulting values should be considered
     approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller.  The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat().  It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data.  This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

	struct statx_timestamp {
		__s64	tv_sec;
		__s32	tv_nsec;
		__s32	__reserved;
	};

	struct statx {
		__u32	stx_mask;
		__u32	stx_blksize;
		__u64	stx_attributes;
		__u32	stx_nlink;
		__u32	stx_uid;
		__u32	stx_gid;
		__u16	stx_mode;
		__u16	__spare0[1];
		__u64	stx_ino;
		__u64	stx_size;
		__u64	stx_blocks;
		__u64	__spare1[1];
		struct statx_timestamp	stx_atime;
		struct statx_timestamp	stx_btime;
		struct statx_timestamp	stx_ctime;
		struct statx_timestamp	stx_mtime;
		__u32	stx_rdev_major;
		__u32	stx_rdev_minor;
		__u32	stx_dev_major;
		__u32	stx_dev_minor;
		__u64	__spare2[14];
	};

The defined bits in request_mask and stx_mask are:

	STATX_TYPE		Want/got stx_mode & S_IFMT
	STATX_MODE		Want/got stx_mode & ~S_IFMT
	STATX_NLINK		Want/got stx_nlink
	STATX_UID		Want/got stx_uid
	STATX_GID		Want/got stx_gid
	STATX_ATIME		Want/got stx_atime{,_ns}
	STATX_MTIME		Want/got stx_mtime{,_ns}
	STATX_CTIME		Want/got stx_ctime{,_ns}
	STATX_INO		Want/got stx_ino
	STATX_SIZE		Want/got stx_size
	STATX_BLOCKS		Want/got stx_blocks
	STATX_BASIC_STATS	[The stuff in the normal stat struct]
	STATX_BTIME		Want/got stx_btime{,_ns}
	STATX_ALL		[All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution.  Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does.  The following
attributes map to FS_*_FL flags and are the same numerical value:

	STATX_ATTR_COMPRESSED		File is compressed by the fs
	STATX_ATTR_IMMUTABLE		File is marked immutable
	STATX_ATTR_APPEND		File is append-only
	STATX_ATTR_NODUMP		File is not to be dumped
	STATX_ATTR_ENCRYPTED		File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

	KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

	STATX_ATTR_AUTOMOUNT		Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

 (0) stx_dev_*, stx_blksize.

     These are local system information and are always available.

 (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
     stx_size, stx_blocks.

     These will be returned whether the caller asks for them or not.  The
     corresponding bits in stx_mask will be set to indicate whether they
     actually have valid values.

     If the caller didn't ask for them, then they may be approximated.  For
     example, NFS won't waste any time updating them from the server,
     unless as a byproduct of updating something requested.

     If the values don't actually exist for the underlying object (such as
     UID or GID on a DOS file), then the bit won't be set in the stx_mask,
     even if the caller asked for the value.  In such a case, the returned
     value will be a fabrication.

     Note that there are instances where the type might not be valid, for
     instance Windows reparse points.

 (2) stx_rdev_*.

     This will be set only if stx_mode indicates we're looking at a
     blockdev or a chardev, otherwise will be 0.

 (3) stx_btime.

     Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

	samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output.  Firstly, an NFS directory that crosses to
another FSID.  Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

	[root@andromeda ~]# /tmp/test-statx -A /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:26           Inode: 1703937     Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000
	Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

	[root@andromeda ~]# /tmp/test-statx /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:27           Inode: 2           Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02 20:51:15 -05:00
Kinglong Mee
52e380e049 NFSD: cleanup dead codes and values in nfsd_write
This is just cleanup, no change in functionality.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-01-31 12:31:53 -05:00
Kinglong Mee
54bbb7d206 NFSD: pass an integer for stable type to nfsd_vfs_write
After fae5096ad2 "nfsd: assume writeable exportabled filesystems have
f_sync" we no longer modify this argument.

This is just cleanup, no change in functionality.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2017-01-31 12:31:53 -05:00
Anna Schumaker
29ae7f9dc2 NFSD: Implement the COPY call
I only implemented the sync version of this call, since it's the
easiest.  I can simply call vfs_copy_range() and have the vfs do the
right thing for the filesystem being exported.

Signed-off-by: Anna Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-10-07 14:54:25 -04:00
J. Bruce Fields
b44061d0b9 nfsd: reorganize nfsd_create
There's some odd logic in nfsd_create() that allows it to be called with
the parent directory either locked or unlocked.  The only already-locked
caller is NFSv2's nfsd_proc_create().  It's less confusing to split out
the unlocked case into a separate function which the NFSv2 code can call
directly.

Also fix some comments while we're here.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-08-04 17:11:49 -04:00
Benjamin Coddington
ac503e4a30 nfsd: use short read as well as i_size to set eof
Use the result of a local read to determine when to set the eof flag.  This
allows us to return the location of the end of the file atomically at the
time of the read.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
[bfields: add some documentation]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2016-03-23 16:02:39 -04:00
Christoph Hellwig
ffa0160a10 nfsd: implement the NFSv4.2 CLONE operation
This is basically a remote version of the btrfs CLONE operation,
so the implementation is fairly trivial.  Made even more trivial
by stealing the XDR code and general framework Anna Schumaker's
COPY prototype.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: J. Bruce Fields <bfields@fieldses.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-07 23:12:00 -05:00
Jeff Layton
aaf91ec148 nfsd: switch unsigned char flags in svc_fh to bools
...just for clarity.

Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-10-12 17:31:04 -04:00
Kinglong Mee
ead8fb8c24 NFSD: Set the attributes used to store the verifier for EXCLUSIVE4_1
According to rfc5661 18.16.4,
"If EXCLUSIVE4_1 was used, the client determines the attributes
 used for the verifier by comparing attrset with cva_attrs.attrmask;"

So, EXCLUSIVE4_1 also needs those bitmask used to store the verifier.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-08-31 16:16:39 -04:00
Christoph Hellwig
af90f707fa nfsd: take struct file setup fully into nfs4_preprocess_stateid_op
This patch changes nfs4_preprocess_stateid_op so it always returns
a valid struct file if it has been asked for that.  For that we
now allocate a temporary struct file for special stateids, and check
permissions if we got the file structure from the stateid.  This
ensures that all callers will get their handling of special stateids
right, and avoids code duplication.

There is a little wart in here because the read code needs to know
if we allocated a file structure so that it can copy around the
read-ahead parameters.  In the long run we should probably aim to
cache full file structures used with special stateids instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-22 14:15:03 -04:00
Christoph Hellwig
e749a4621e nfsd: clean up raparams handling
Refactor the raparam hash helpers to just deal with the raparms,
and keep opening/closing files separate from that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-06-19 15:39:51 -04:00
Christoph Hellwig
fd89145460 nfsd: remove nfsd_close
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-05-04 12:02:43 -04:00
Linus Torvalds
0b233b7c79 Merge branch 'for-3.19' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
 "A comparatively quieter cycle for nfsd this time, but still with two
  larger changes:

   - RPC server scalability improvements from Jeff Layton (using RCU
     instead of a spinlock to find idle threads).

   - server-side NFSv4.2 ALLOCATE/DEALLOCATE support from Anna
     Schumaker, enabling fallocate on new clients"

* 'for-3.19' of git://linux-nfs.org/~bfields/linux: (32 commits)
  nfsd4: fix xdr4 count of server in fs_location4
  nfsd4: fix xdr4 inclusion of escaped char
  sunrpc/cache: convert to use string_escape_str()
  sunrpc: only call test_bit once in svc_xprt_received
  fs: nfsd: Fix signedness bug in compare_blob
  sunrpc: add some tracepoints around enqueue and dequeue of svc_xprt
  sunrpc: convert to lockless lookup of queued server threads
  sunrpc: fix potential races in pool_stats collection
  sunrpc: add a rcu_head to svc_rqst and use kfree_rcu to free it
  sunrpc: require svc_create callers to pass in meaningful shutdown routine
  sunrpc: have svc_wake_up only deal with pool 0
  sunrpc: convert sp_task_pending flag to use atomic bitops
  sunrpc: move rq_cachetype field to better optimize space
  sunrpc: move rq_splice_ok flag into rq_flags
  sunrpc: move rq_dropme flag into rq_flags
  sunrpc: move rq_usedeferral flag to rq_flags
  sunrpc: move rq_local field to rq_flags
  sunrpc: add a generic rq_flags field to svc_rqst and move rq_secure to it
  nfsd: minor off by one checks in __write_versions()
  sunrpc: release svc_pool_map reference when serv allocation fails
  ...
2014-12-16 15:25:31 -08:00
Anna Schumaker
95d871f03c nfsd: Add ALLOCATE support
The ALLOCATE operation is used to preallocate space in a file.  I can do
this by using vfs_fallocate() to do the actual preallocation.

ALLOCATE only returns a status indicator, so we don't need to write a
special encode() function.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-11-07 16:19:49 -05:00
Miklos Szeredi
ac7576f4b1 vfs: make first argument of dir_context.actor typed
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31 17:48:54 -04:00
Kinglong Mee
1e444f5bc0 NFSD: Remove iattr parameter from nfsd_symlink()
Commit db2e747b14 (vfs: remove mode parameter from vfs_symlink())
have remove mode parameter from vfs_symlink.
So that, iattr isn't needed by nfsd_symlink now, just remove it.

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:31 -04:00
J. Bruce Fields
52ee04330f nfsd: let nfsd_symlink assume null-terminated data
Currently nfsd_symlink has a weird hack to serve callers who don't
null-terminate symlink data: it looks ahead at the next byte to see if
it's zero, and copies it to a new buffer to null-terminate if not.

That means callers don't have to null-terminate, but they *do* have to
ensure that the byte following the end of the data is theirs to read.

That's a bit subtle, and the NFSv4 code actually got this wrong.

So let's just throw out that code and let callers pass null-terminated
strings; we've already fixed them to do that.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-07-08 17:14:23 -04:00
Jeff Layton
e2afc81919 nfsd: nfsd_splice_read and nfsd_readv should return __be32
The callers expect a __be32 return and the functions they call return
__be32, so having these return int is just wrong. Also, nfsd_finish_read
can be made static.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-06-23 11:31:37 -04:00
Christoph Hellwig
b52bd7bccc nfsd: remove unused function nfsd_read_file
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:27 -04:00
J. Bruce Fields
dc97618ddd nfsd4: separate splice and readv cases
The splice and readv cases are actually quite different--for example the
former case ignores the array of vectors we build up for the latter.

It is probably clearer to separate the two cases entirely.

There's some code duplication between the split out encoders, but this
is only temporary and will be fixed by a later patch.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-05-30 17:32:09 -04:00
Linus Torvalds
d9894c228b Merge branch 'for-3.14' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
 - Handle some loose ends from the vfs read delegation support.
   (For example nfsd can stop breaking leases on its own in a
    fewer places where it can now depend on the vfs to.)
 - Make life a little easier for NFSv4-only configurations
   (thanks to Kinglong Mee).
 - Fix some gss-proxy problems (thanks Jeff Layton).
 - miscellaneous bug fixes and cleanup

* 'for-3.14' of git://linux-nfs.org/~bfields/linux: (38 commits)
  nfsd: consider CLAIM_FH when handing out delegation
  nfsd4: fix delegation-unlink/rename race
  nfsd4: delay setting current_fh in open
  nfsd4: minor nfs4_setlease cleanup
  gss_krb5: use lcm from kernel lib
  nfsd4: decrease nfsd4_encode_fattr stack usage
  nfsd: fix encode_entryplus_baggage stack usage
  nfsd4: simplify xdr encoding of nfsv4 names
  nfsd4: encode_rdattr_error cleanup
  nfsd4: nfsd4_encode_fattr cleanup
  minor svcauth_gss.c cleanup
  nfsd4: better VERIFY comment
  nfsd4: break only delegations when appropriate
  NFSD: Fix a memory leak in nfsd4_create_session
  sunrpc: get rid of use_gssp_lock
  sunrpc: fix potential race between setting use_gss_proxy and the upcall rpc_clnt
  sunrpc: don't wait for write before allowing reads from use-gss-proxy file
  nfsd: get rid of unused function definition
  Define op_iattr for nfsd4_open instead using macro
  NFSD: fix compile warning without CONFIG_NFSD_V3
  ...
2014-01-30 10:18:43 -08:00
Christoph Hellwig
4ac7249ea5 nfsd: use get_acl and ->set_acl
Remove the boilerplate code to marshall and unmarhall ACL objects into
xattrs and operate on the posix_acl objects directly.  Also move all
the ACL handling code into nfs?acl.c where it belongs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-01-26 08:26:41 -05:00
Kinglong Mee
73ca65904c nfsd: get rid of unused function definition
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-01-06 12:23:33 -05:00
David Quigley
18032ca062 NFSD: Server implementation of MAC Labeling
Implement labeled NFS on the server: encoding and decoding, and writing
and reading, of file labels.

Enabled with CONFIG_NFSD_V4_SECURITY_LABEL.

Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-05-15 09:27:02 -04:00
Zhao Hongjiang
eb48241bb4 nfsd: get rid of the unused functions in vfs
The fh_lock_parent(), nfsd_truncate(), nfsd_notify_change() and
nfsd_sync_dir() fuctions are neither implemented nor used, just remove
them.

Signed-off-by: Zhao Hongjiang <zhaohongjiang@huawei.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-05-13 10:11:44 -04:00
Al Viro
3dadecce20 switch vfs_getattr() to struct path
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-26 02:46:08 -05:00