user/sven/linux.git/include/linux/bio.h, branch v6.5.5

block: don't make REQ_POLLED imply REQ_NOWAIT

2023-08-09T22:04:07Z

Normally these two flags do go together, as the issuer of polled IO generally cannot wait for resources that will get freed as part of IO completion. This is because that very task is the one that will complete the request and free those resources, hence that would introduce a deadlock. But it is possible to have someone else issue the polled IO, eg via io_uring if the request is punted to io-wq. For that case, it's fine to have the task block on IO submission, as it is not the same task that will be completing the IO. It's completely up to the caller to ask for both polled and nowait IO separately! If we don't allow polled IO where IOCB_NOWAIT isn't set in the kiocb, then we can run into repeated -EAGAIN submissions and not make any progress. Reviewed-by: Bart Van Assche Signed-off-by: Jens Axboe

block: remove BIO_PAGE_REFFED

2023-06-16T16:08:09Z

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

2023-06-01T15:13:31Z

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

2023-06-01T15:13:31Z

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

2023-06-01T15:13:31Z

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

2023-05-24T14:42:44Z

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

2023-05-24T14:42:44Z

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

2023-05-24T14:42:44Z

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

2023-04-17T16:01:22Z

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

2023-02-15T18:38:50Z

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