linux-stable.git/fs/splice.c, branch v6.2

use less confusing names for iov_iter direction initializers

2022-11-25T18:01:55+00:00

READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro

iter_to_pipe(): switch to advancing variant of iov_iter_get_pages()

2022-08-09T02:37:23+00:00

... and untangle the cleanup on failure to add into pipe.

Reviewed-by: Jeff Layton 
Signed-off-by: Al Viro

splice: stop abusing iov_iter_advance() to flush a pipe

2022-08-09T02:37:16+00:00

Use pipe_discard_from() explicitly in generic_file_read_iter(); don't bother
with rather non-obvious use of iov_iter_advance() in there.

Reviewed-by: Jeff Layton 
Reviewed-by: Christian Brauner (Microsoft) 
Signed-off-by: Al Viro

fs: check FMODE_LSEEK to control internal pipe splicing

2022-07-16T13:19:16+00:00

The original direct splicing mechanism from Jens required the input to
be a regular file because it was avoiding the special socket case. It
also recognized blkdevs as being close enough to a regular file. But it
forgot about chardevs, which behave the same way and work fine here.

This is an okayish heuristic, but it doesn't totally work. For example,
a few chardevs should be spliceable here. And a few regular files
shouldn't. This patch fixes this by instead checking whether FMODE_LSEEK
is set, which represents decently enough what we need rewinding for when
splicing to internal pipes.

Fixes: b92ce5589374 ("[PATCH] splice: add direct fd <-> fd splicing support")
Cc: Jens Axboe 
Signed-off-by: Jason A. Donenfeld 
Signed-off-by: Al Viro

mm: Convert remove_mapping() to take a folio

2022-03-21T16:59:01+00:00

Add kernel-doc and return the number of pages removed in order to
get the statistics right in __invalidate_mapping_pages().

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Miaohe Lin

splice: Use a folio in page_cache_pipe_buf_try_steal()

2022-03-21T16:59:01+00:00

This saves a lot of calls to compound_head().

Signed-off-by: Matthew Wilcox (Oracle) 
Reviewed-by: Christoph Hellwig 
Reviewed-by: Miaohe Lin

Merge tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block

2021-02-21T19:02:48+00:00

Pull core block updates from Jens Axboe:
 "Another nice round of removing more code than what is added, mostly
  due to Christoph's relentless pursuit of tech debt removal/cleanups.
  This pull request contains:

   - Two series of BFQ improvements (Paolo, Jan, Jia)

   - Block iov_iter improvements (Pavel)

   - bsg error path fix (Pan)

   - blk-mq scheduler improvements (Jan)

   - -EBUSY discard fix (Jan)

   - bvec allocation improvements (Ming, Christoph)

   - bio allocation and init improvements (Christoph)

   - Store bdev pointer in bio instead of gendisk + partno (Christoph)

   - Block trace point cleanups (Christoph)

   - hard read-only vs read-only split (Christoph)

   - Block based swap cleanups (Christoph)

   - Zoned write granularity support (Damien)

   - Various fixes/tweaks (Chunguang, Guoqing, Lei, Lukas, Huhai)"

* tag 'for-5.12/block-2021-02-17' of git://git.kernel.dk/linux-block: (104 commits)
  mm: simplify swapdev_block
  sd_zbc: clear zone resources for non-zoned case
  block: introduce blk_queue_clear_zone_settings()
  zonefs: use zone write granularity as block size
  block: introduce zone_write_granularity limit
  block: use blk_queue_set_zoned in add_partition()
  nullb: use blk_queue_set_zoned() to setup zoned devices
  nvme: cleanup zone information initialization
  block: document zone_append_max_bytes attribute
  block: use bi_max_vecs to find the bvec pool
  md/raid10: remove dead code in reshape_request
  block: mark the bio as cloned in bio_iov_bvec_set
  block: set BIO_NO_PAGE_REF in bio_iov_bvec_set
  block: remove a layer of indentation in bio_iov_iter_get_pages
  block: turn the nr_iovecs argument to bio_alloc* into an unsigned short
  block: remove the 1 and 4 vec bvec_slabs entries
  block: streamline bvec_alloc
  block: factor out a bvec_alloc_gfp helper
  block: move struct biovec_slab to bio.c
  block: reuse BIO_INLINE_VECS for integrity bvecs
  ...

teach sendfile(2) to handle send-to-pipe directly

2021-01-26T04:29:36+00:00

no point going through the intermediate pipe

Signed-off-by: Al Viro

take the guts of file-to-pipe splice into a helper function

2021-01-26T04:29:33+00:00

Signed-off-by: Al Viro

do_splice_to(): move the logics for limiting the read length in

2021-01-26T04:28:41+00:00

Both callers have the identical logics limiting the amount of
data we try to read into pipe - no more than would fit into
that pipe.  Move that into do_splice_to() itself.

Signed-off-by: Al Viro