linux.git/include/linux/bio.h, branch v6.5-rc4

block: remove BIO_PAGE_REFFED

2023-06-16T16:08:09+00:00

Now that all block direct I/O helpers use page pinning, this flag is
unused.

Signed-off-by: Christoph Hellwig 
Reviewed-by: Christian Brauner 
Reviewed-by: Johannes Thumshirn 
Reviewed-by: David Howells 
Link: https://lore.kernel.org/r/20230614140341.521331-4-hch@lst.de
Signed-off-by: Jens Axboe

block: mark bio_add_folio as __must_check

2023-06-01T15:13:31+00:00

Now that all callers of bio_add_folio() check the return value, mark it as
__must_check.

Reviewed-by: Matthew Wilcox (Oracle) 
Signed-off-by: Johannes Thumshirn 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/381360a45ac3684120cfbe1e07685e9c36256e47.1685532726.git.johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe

block: add bio_add_folio_nofail

2023-06-01T15:13:31+00:00

Just like for bio_add_pages() add a no-fail variant for bio_add_folio().

Reviewed-by: Matthew Wilcox (Oracle) 
Signed-off-by: Johannes Thumshirn 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/924dff4077812804398ef84128fb920507fa4be1.1685532726.git.johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe

block: mark bio_add_page as __must_check

2023-06-01T15:13:31+00:00

Now that all users of bio_add_page check for the return value, mark
bio_add_page as __must_check.

Reviewed-by: Damien Le Moal 
Signed-off-by: Johannes Thumshirn 
Reviewed-by: Christoph Hellwig 
Link: https://lore.kernel.org/r/7ae4a902e08fe2e90c012ee07aeb35d4aae28373.1685532726.git.johannes.thumshirn@wdc.com
Signed-off-by: Jens Axboe

block: Add BIO_PAGE_PINNED and associated infrastructure

2023-05-24T14:42:44+00:00

Add BIO_PAGE_PINNED to indicate that the pages in a bio are pinned
(FOLL_PIN) and that the pin will need removing.

Signed-off-by: David Howells 
Reviewed-by: Christoph Hellwig 
Reviewed-by: John Hubbard 
cc: Al Viro 
cc: Jens Axboe 
cc: Jan Kara 
cc: Matthew Wilcox 
cc: Logan Gunthorpe 
cc: linux-block@vger.kernel.org
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20230522205744.2825689-5-dhowells@redhat.com
Signed-off-by: Jens Axboe

block: Replace BIO_NO_PAGE_REF with BIO_PAGE_REFFED with inverted logic

2023-05-24T14:42:44+00:00

Replace BIO_NO_PAGE_REF with a BIO_PAGE_REFFED flag that has the inverted
meaning is only set when a page reference has been acquired that needs to
be released by bio_release_pages().

Signed-off-by: Christoph Hellwig 
Signed-off-by: David Howells 
Reviewed-by: John Hubbard 
cc: Al Viro 
cc: Jens Axboe 
cc: Jan Kara 
cc: Matthew Wilcox 
cc: Logan Gunthorpe 
cc: linux-block@vger.kernel.org
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20230522205744.2825689-4-dhowells@redhat.com
Signed-off-by: Jens Axboe

block: Fix bio_flagged() so that gcc can better optimise it

2023-05-24T14:42:44+00:00

Fix bio_flagged() so that multiple instances of it, such as:

	if (bio_flagged(bio, BIO_PAGE_REFFED) ||
	    bio_flagged(bio, BIO_PAGE_PINNED))

can be combined by the gcc optimiser into a single test in assembly
(arguably, this is a compiler optimisation issue[1]).

The missed optimisation stems from bio_flagged() comparing the result of
the bitwise-AND to zero.  This results in an out-of-line bio_release_page()
being compiled to something like:

   <+0>:     mov    0x14(%rdi),%eax
   <+3>:     test   $0x1,%al
   <+5>:     jne    0xffffffff816dac53 
   <+7>:     test   $0x2,%al
   <+9>:     je     0xffffffff816dac5c 
   <+11>:    movzbl %sil,%esi
   <+15>:    jmp    0xffffffff816daba1 <__bio_release_pages>
   <+20>:    jmp    0xffffffff81d0b800 <__x86_return_thunk>

However, the test is superfluous as the return type is bool.  Removing it
results in:

   <+0>:     testb  $0x3,0x14(%rdi)
   <+4>:     je     0xffffffff816e4af4 
   <+6>:     movzbl %sil,%esi
   <+10>:    jmp    0xffffffff816dab7c <__bio_release_pages>
   <+15>:    jmp    0xffffffff81d0b7c0 <__x86_return_thunk>

instead.

Also, the MOVZBL instruction looks unnecessary[2] - I think it's just
're-booling' the mark_dirty parameter.

Signed-off-by: David Howells 
Reviewed-by: Christoph Hellwig 
Reviewed-by: John Hubbard 
cc: Jens Axboe 
cc: linux-block@vger.kernel.org
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108370 [1]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108371 [2]
Link: https://lore.kernel.org/r/167391056756.2311931.356007731815807265.stgit@warthog.procyon.org.uk/ # v6
Reviewed-by: Christian Brauner 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/20230522205744.2825689-3-dhowells@redhat.com
Signed-off-by: Jens Axboe

btrfs, block: move REQ_CGROUP_PUNT to btrfs

2023-04-17T16:01:22+00:00

REQ_CGROUP_PUNT is a bit annoying as it is hard to follow and adds
a branch to the bio submission hot path.  To fix this, export
blkcg_punt_bio_submit and let btrfs call it directly.  Add a new
REQ_FS_PRIVATE flag for btrfs to indicate to it's own low-level
bio submission code that a punt to the cgroup submission helper
is required.

Reviewed-by: Jens Axboe 
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

block: export bio_split_rw

2023-02-15T18:38:50+00:00

bio_split_rw can be used by file systems to split and incoming write
bio into multiple bios fitting the hardware limit for use as ZONE_APPEND
bios.  Export it for initial use in btrfs.

Reviewed-by: Josef Bacik 
Reviewed-by: Chaitanya Kulkarni 
Reviewed-by: Johannes Thumshirn 
Signed-off-by: Christoph Hellwig 
Reviewed-by: David Sterba 
Signed-off-by: David Sterba

Revert "block: bio_copy_data_iter"

2023-01-04T21:43:27+00:00

This reverts commit db1c7d77976775483a8ef240b4c705f113e13ea1.

We're reinstating the pktcdvd driver, which needs this API.

Signed-off-by: Jens Axboe