Strengthen the checking of pos/len vs. i_size, clarify the return values
for the clone prep function, and remove pointless code.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

With overlayfs, it is wrong to compare file_inode(inode)->i_sb
of regular files with those of non-regular files, because the
former reference the real (upper/lower) sb and the latter reference
the overlayfs sb.

Move the test for same super block after the sanity tests for
clone range of directory and non-regular file.

This change fixes xfstest generic/157, which returned EXDEV instead
of EISDIR/EINVAL in the following test cases over overlayfs:

  echo "Try to reflink a dir"
  _reflink_range $testdir1/dir1 0 $testdir1/file2 0 $blksz

  echo "Try to reflink a device"
  _reflink_range $testdir1/dev1 0 $testdir1/file2 0 $blksz
Signed-off-by: NAmir Goldstein <amir73il@gmail.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

Move sb_start_write()/sb_end_write() out of the vfs helper and up into the
ioctl handler.
Signed-off-by: NAmir Goldstein <amir73il@gmail.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

FICLONE/FICLONERANGE ioctls return -EXDEV if src and dest
files are not on the same mount point.
Practically, clone only requires that src and dest files
are on the same file system.

Move the check for same mount point to ioctl handler and keep
only the check for same super block in the vfs helper.

A following patch is going to use the vfs_clone_file_range()
helper in overlayfs to copy up between lower and upper
mount points on the same file system.
Signed-off-by: NAmir Goldstein <amir73il@gmail.com>
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

We've checked for file_out being opened for write.  This ensures that we
already have mnt_want_write() on target.
Signed-off-by: NMiklos Szeredi <mszeredi@redhat.com>

Hoist both the XFS reflink inode state and preparation code and the XFS
file blocks compare functions into the VFS so that ocfs2 can take
advantage of it for reflink and dedupe.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

A clone is a perfectly fine implementation of a file copy, so most
file systems just implement the copy that way.  Instead of duplicating
this logic move it to the VFS.  Currently btrfs and XFS implement copies
the same way as clones and there is no behavior change for them, cifs
only implements clones and grow support for copy_file_range with this
patch.  NFS implements both, so this will allow copy_file_range to work
on servers that only implement CLONE and be lot more efficient on servers
that implements CLONE and COPY.
Signed-off-by: NChristoph Hellwig <hch@lst.de>

Both import_iovec() and rw_copy_check_uvector() take an array
(typically small and on-stack) which is used to hold an iovec array copy
from userspace. This is to avoid an expensive memory allocation in the
fast path (i.e. few iovec elements).

The caller may have to check whether these functions actually used
the provided buffer or allocated a new one -- but this differs between
the too. Let's just add a kernel doc to clarify what the semantics are
for each function.
Signed-off-by: NVegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Don't use the same syscall numbers for 2 different syscalls:

 534	x32	preadv			compat_sys_preadv64
 535	x32	pwritev			compat_sys_pwritev64
 534	x32	preadv2			compat_sys_preadv2
 535	x32	pwritev2		compat_sys_pwritev2

Add compat_sys_preadv64v2() and compat_sys_pwritev64v2() so that 64-bit offset
is passed in one 64-bit register on x32, similar to compat_sys_preadv64()
and compat_sys_pwritev64().
Signed-off-by: NH.J. Lu <hjl.tools@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/CAMe9rOovCMf-RQfx_n1U_Tu_DX1BYkjtFr%3DQ4-_PFVSj9BCzUA@mail.gmail.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

same as read() on regular files has, and for the same reason.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This is the per-I/O equivalent of O_DSYNC and O_SYNC, and very useful for
all kinds of file servers and storage targets.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Lift length capping into the few callers that care about it.  Most of
them treat all non-negatives as "success" and ignore the capped value,
and with good reasons.

Make rw_verify_area() return 0 on success.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This adds a flag that tells the file system that this is a high priority
request for which it's worth to poll the hardware.  The flag is purely
advisory and can be ignored if not supported.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NStephen Bates <stephen.bates@pmcs.com>
Tested-by: NStephen Bates <stephen.bates@pmcs.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

New syscalls that take an flag argument.   No flags are added yet in this
patch.
Signed-off-by: NMilosz Tanski <milosz@adfin.com>
[hch: rebased on top of my kiocb changes]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NStephen Bates <stephen.bates@pmcs.com>
Tested-by: NStephen Bates <stephen.bates@pmcs.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This way we can set kiocb flags also from the sync read/write path for
the read_iter/write_iter operations.  For now there is no way to pass
flags to plain read/write operations as there is no real need for that,
and all flags passed are explicitly rejected for these files.
Signed-off-by: NMilosz Tanski <milosz@adfin.com>
[hch: rebased on top of my kiocb changes]
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NStephen Bates <stephen.bates@pmcs.com>
Tested-by: NStephen Bates <stephen.bates@pmcs.com>
Acked-by: NJeff Moyer <jmoyer@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

-EBADF is a rather confusing error if an operations is not supported,
and nfsd gets rather upset about it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The user-visible impact of the issue is for example that without this
patch sensors-detect breaks when trying to seek in /dev/cpu/0/cpuid.

'~0ULL' is a 'unsigned long long' that when converted to a loff_t,
which is signed, gets turned into -1. later in vfs_setpos we have
'if (offset > maxsize)', which makes it always return EINVAL.

Fixes: b25472f9 ("new helpers: no_seek_end_llseek{,_size}()")
Signed-off-by: NWouter van Kesteren <woutershep@gmail.com>
Reviewed-by: NAndreas Dilger <adilger@dilger.ca>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

If the program running dedupe receives a fatal signal during the
dedupe loop, we should bail out to avoid tying up the system.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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: NAl Viro <viro@zeniv.linux.org.uk>

Hoist the btrfs EXTENT_SAME ioctl up to the VFS and make the name
more systematic (FIDEDUPERANGE).
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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

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

Pass a loff_t end for the last byte instead of the 32-bit count
parameter to allow full file clones even on 32-bit architectures.
While we're at it also simplify the read/write selection.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This allows us to have an in-kernel copy mechanism that avoids frequent
switches between kernel and user space.  This is especially useful so
NFSD can support server-side copies.

The default (flags=0) means to first attempt copy acceleration, but use
the pagecache if that fails.
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NPadraig Brady <P@draigBrady.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add a copy_file_range() system call for offloading copies between
regular files.

This gives an interface to underlying layers of the storage stack which
can copy without reading and writing all the data.  There are a few
candidates that should support copy offloading in the nearer term:

- btrfs shares extent references with its clone ioctl
- NFS has patches to add a COPY command which copies on the server
- SCSI has a family of XCOPY commands which copy in the device

This system call avoids the complexity of also accelerating the creation
of the destination file by operating on an existing destination file
descriptor, not a path.

Currently the high level vfs entry point limits copy offloading to files
on the same mount and super (and not in the same file).  This can be
relaxed if we get implementations which can copy between file systems
safely.
Signed-off-by: NZach Brown <zab@redhat.com>
[Anna Schumaker: Change -EINVAL to -EBADF during file verification,
                 Change flags parameter from int to unsigned int,
                 Add function to include/linux/syscalls.h,
                 Check copy len after file open mode,
                 Don't forbid ranges inside the same file,
                 Use rw_verify_area() to veriy ranges,
                 Use file_out rather than file_in,
                 Add COPY_FR_REFLINK flag]
Signed-off-by: NAnna Schumaker <Anna.Schumaker@Netapp.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

That allows ->write_iter() instances much more convenient life wrt
iocb->ki_pos (and fixes several filesystems with borderline POSIX
violations when zero-length write succeeds and changes the current
position).
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

no remaining users
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

all remaining instances of aio_{read,write} (all 4 of them) have explicit
->read and ->write resp.; do_sync_read/do_sync_write is never called by
__vfs_read/__vfs_write anymore and no other users had been left.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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: NAl Viro <viro@zeniv.linux.org.uk>

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

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

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

get it closer to matching {compat_,}rw_copy_check_uvector().
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The AIO interface is fairly complex because it tries to allow
filesystems to always work async and then wakeup a synchronous
caller through aio_complete.  It turns out that basically no one
was doing this to avoid the complexity and context switches,
and we've already fixed up the remaining users and can now
get rid of this case.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

There is no need to pass the total request length in the kiocb, as
we already get passed in through the iov_iter argument.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Simple helpers that pass an arbitrary iov_iter to filesystems.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NJeff Layton <jlayton@primarydata.com>
Acked-by: NChristoph Hellwig <hch@lst.de>

integrity_kernel_read() duplicates the file read operations code
in vfs_read(). This patch refactors vfs_read() code creating a
helper function __vfs_read(). It is used by both vfs_read() and
integrity_kernel_read().
Signed-off-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>