linux-toradex.git/lib/iov_iter.c, branch v4.20-rc6

iov_iter: teach csum_and_copy_to_iter() to handle pipe-backed ones

2018-11-25T21:24:49+00:00

Signed-off-by: Al Viro

iov_iter: Add I/O discard iterator

2018-10-23T23:41:07+00:00

Add a new iterator, ITER_DISCARD, that can only be used in READ mode and
just discards any data copied to it.

This is useful in a network filesystem for discarding any unwanted data
sent by a server.

Signed-off-by: David Howells

iov_iter: Separate type from direction and use accessor functions

2018-10-23T23:41:07+00:00

In the iov_iter struct, separate the iterator type from the iterator
direction and use accessor functions to access them in most places.

Convert a bunch of places to use switch-statements to access them rather
then chains of bitwise-AND statements.  This makes it easier to add further
iterator types.  Also, this can be more efficient as to implement a switch
of small contiguous integers, the compiler can use ~50% fewer compare
instructions than it has to use bitwise-and instructions.

Further, cease passing the iterator type into the iterator setup function.
The iterator function can set that itself.  Only the direction is required.

Signed-off-by: David Howells

iov_iter: Use accessor function

2018-10-23T23:40:44+00:00

Use accessor functions to access an iterator's type and direction.  This
allows for the possibility of using some other method of determining the
type of iterator than if-chains with bitwise-AND conditions.

Signed-off-by: David Howells

lib/iov_iter: Fix pipe handling in _copy_to_iter_mcsafe()

2018-07-15T22:05:05+00:00

By mistake the ITER_PIPE early-exit / warning from copy_from_iter() was
cargo-culted in _copy_to_iter_mcsafe() rather than a machine-check-safe
version of copy_to_iter_pipe().

Implement copy_pipe_to_iter_mcsafe() being careful to return the
indication of short copies due to a CPU exception.

Without this regression-fix all splice reads to dax-mode files fail.

Reported-by: Ross Zwisler 
Tested-by: Ross Zwisler 
Signed-off-by: Dan Williams 
Acked-by: Al Viro 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Fixes: 8780356ef630 ("x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()")
Link: http://lkml.kernel.org/r/153108277278.37979.3327916996902264102.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar

lib/iov_iter: Document _copy_to_iter_flushcache()

2018-07-15T22:05:05+00:00

Add some theory of operation documentation to _copy_to_iter_flushcache().

Reported-by: Al Viro 
Signed-off-by: Dan Williams 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Link: http://lkml.kernel.org/r/153108276767.37979.9462477994086841699.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar

lib/iov_iter: Document _copy_to_iter_mcsafe()

2018-07-15T22:05:05+00:00

Add some theory of operation documentation to _copy_to_iter_mcsafe().

Reported-by: Al Viro 
Signed-off-by: Dan Williams 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Link: http://lkml.kernel.org/r/153108276256.37979.1689794213845539316.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar

Merge branch 'x86-dax-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-06-05T02:23:13+00:00

Pull x86 dax updates from Ingo Molnar:
 "This contains x86 memcpy_mcsafe() fault handling improvements the
  nvdimm tree would like to make more use of"

* 'x86-dax-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()
  x86/asm/memcpy_mcsafe: Add write-protection-fault handling
  x86/asm/memcpy_mcsafe: Return bytes remaining
  x86/asm/memcpy_mcsafe: Add labels for __memcpy_mcsafe() write fault handling
  x86/asm/memcpy_mcsafe: Remove loop unrolling

x86/asm/memcpy_mcsafe: Define copy_to_iter_mcsafe()

2018-05-15T06:32:42+00:00

Use the updated memcpy_mcsafe() implementation to define
copy_user_mcsafe() and copy_to_iter_mcsafe(). The most significant
difference from typical copy_to_iter() is that the ITER_KVEC and
ITER_BVEC iterator types can fail to complete a full transfer.

Signed-off-by: Dan Williams 
Cc: Al Viro 
Cc: Andrew Morton 
Cc: Andy Lutomirski 
Cc: Borislav Petkov 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Tony Luck 
Cc: hch@lst.de
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/152539239150.31796.9189779163576449784.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar

iov_iter: fix memory leak in pipe_get_pages_alloc()

2018-05-02T19:43:19+00:00

Make n signed to avoid leaking the pages array if __pipe_get_pages()
fails to allocate any pages.

Signed-off-by: Ilya Dryomov 
Signed-off-by: Al Viro