kernel/linux.git/fs/buffer.c, branch linux-6.0.y

mm: fs: initialize fsdata passed to write_begin/write_end interface

2022-11-26T08:27:56+00:00

commit 1468c6f4558b1bcd92aa0400f2920f9dc7588402 upstream. Functions implementing the a_ops->write_end() interface accept the `void *fsdata` parameter that is supposed to be initialized by the corresponding a_ops->write_begin() (which accepts `void **fsdata`). However not all a_ops->write_begin() implementations initialize `fsdata` unconditionally, so it may get passed uninitialized to a_ops->write_end(), resulting in undefined behavior. Fix this by initializing fsdata with NULL before the call to write_begin(), rather than doing so in all possible a_ops implementations. This patch covers only the following cases found by running x86 KMSAN under syzkaller: - generic_perform_write() - cont_expand_zero() and generic_cont_expand_simple() - page_symlink() Other cases of passing uninitialized fsdata may persist in the codebase. Link: https://lkml.kernel.org/r/20220915150417.722975-43-glider@google.com Signed-off-by: Alexander Potapenko Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Marco Elver Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache

2022-08-03T17:35:43+00:00

Pull folio updates from Matthew Wilcox: - Fix an accounting bug that made NR_FILE_DIRTY grow without limit when running xfstests - Convert more of mpage to use folios - Remove add_to_page_cache() and add_to_page_cache_locked() - Convert find_get_pages_range() to filemap_get_folios() - Improvements to the read_cache_page() family of functions - Remove a few unnecessary checks of PageError - Some straightforward filesystem conversions to use folios - Split PageMovable users out from address_space_operations into their own movable_operations - Convert aops->migratepage to aops->migrate_folio - Remove nobh support (Christoph Hellwig) * tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits) fs: remove the NULL get_block case in mpage_writepages fs: don't call ->writepage from __mpage_writepage fs: remove the nobh helpers jfs: stop using the nobh helper ext2: remove nobh support ntfs3: refactor ntfs_writepages mm/folio-compat: Remove migration compatibility functions fs: Remove aops->migratepage() secretmem: Convert to migrate_folio hugetlb: Convert to migrate_folio aio: Convert to migrate_folio f2fs: Convert to filemap_migrate_folio() ubifs: Convert to filemap_migrate_folio() btrfs: Convert btrfs_migratepage to migrate_folio mm/migrate: Add filemap_migrate_folio() mm/migrate: Convert migrate_page() to migrate_folio() nfs: Convert to migrate_folio btrfs: Convert btree_migratepage to migrate_folio mm/migrate: Convert expected_page_refs() to folio_expected_refs() mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio() ...

fs: remove the nobh helpers

2022-08-02T16:34:04+00:00

All callers are gone, so remove the now dead code. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Matthew Wilcox (Oracle)

buffer: Don't test folio error in block_read_full_folio()

2022-08-02T16:34:02+00:00

We can cache this information in a local variable instead of communicating from one part of the function to another via folio flags. Signed-off-by: Matthew Wilcox (Oracle)

fs/buffer: Fix the ll_rw_block() kernel-doc header

2022-07-15T19:10:04+00:00

Bring the ll_rw_block() kernel-doc header again in sync with the function prototype. Reported-by: Stephen Rothwell Cc: Alexander Viro Cc: Jan Kara Cc: Stephen Rothwell Fixes: 1420c4a549bf ("fs/buffer: Combine two submit_bh() and ll_rw_block() arguments") Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220715184735.2326034-2-bvanassche@acm.org Signed-off-by: Jens Axboe

fs/buffer: Combine two submit_bh() and ll_rw_block() arguments

2022-07-14T18:14:32+00:00

Both submit_bh() and ll_rw_block() accept a request operation type and request flags as their first two arguments. Micro-optimize these two functions by combining these first two arguments into a single argument. This patch does not change the behavior of any of the modified code. Cc: Alexander Viro Cc: Jan Kara Acked-by: Song Liu (for the md changes) Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220714180729.1065367-48-bvanassche@acm.org Signed-off-by: Jens Axboe

fs/buffer: Use the new blk_opf_t type

2022-07-14T18:14:32+00:00

Improve static type checking by using the new blk_opf_t type for block layer request flags. Change WRITE into REQ_OP_WRITE. This patch does not change any functionality since REQ_OP_WRITE == WRITE == 1. Reviewed-by: Jan Kara Cc: Al Viro Cc: Christoph Hellwig Cc: Matthew Wilcox Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220714180729.1065367-47-bvanassche@acm.org Signed-off-by: Jens Axboe

buffer: Remove check for PageError

2022-06-29T12:51:07+00:00

If a buffer is completed with an error, its uptodate flag will be clear, so the page_uptodate variable will have been set to 0. There's no need to check PageError here. Signed-off-by: Matthew Wilcox (Oracle)

buffer: Convert clean_bdev_aliases() to use filemap_get_folios()

2022-06-29T12:51:05+00:00

Use a folio throughout this function. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Christoph Hellwig Acked-by: Christian Brauner (Microsoft)

fs: Convert drop_buffers() to use a folio

2022-05-10T03:12:34+00:00

All callers now have a folio. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Jeff Layton