linux-dev/fs/hfsplus, branch master

hfsplus: convert kmap() to kmap_local_page() in btree.c

2022-09-12T04:55:05Z

kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap's pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. Since its use in btree.c is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in btree.c. Tested in a QEMU/KVM x86_32 VM, 6GB RAM, booting a kernel with HIGHMEM64GB enabled. Link: https://lkml.kernel.org/r/20220809203105.26183-5-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco Suggested-by: Ira Weiny Reviewed-by: Ira Weiny Reviewed-by: Viacheslav Dubeyko Cc: Bart Van Assche Cc: Jens Axboe Cc: Kees Cook Cc: Matthew Wilcox Cc: Muchun Song Signed-off-by: Andrew Morton

hfsplus: convert kmap() to kmap_local_page() in bitmap.c

2022-09-12T04:55:04Z

kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap's pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and are still valid. Since its use in bitmap.c is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in bitmap.c. Tested in a QEMU/KVM x86_32 VM, 6GB RAM, booting a kernel with HIGHMEM64GB enabled. Link: https://lkml.kernel.org/r/20220809203105.26183-4-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco Suggested-by: Ira Weiny Reviewed-by: Ira Weiny Reviewed-by: Viacheslav Dubeyko Cc: Bart Van Assche Cc: Jens Axboe Cc: Kees Cook Cc: Matthew Wilcox Cc: Muchun Song Signed-off-by: Andrew Morton

hfsplus: convert kmap() to kmap_local_page() in bnode.c

2022-09-12T04:55:04Z

kmap() is being deprecated in favor of kmap_local_page(). Two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap's pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. Since its use in bnode.c is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in bnode.c. Where possible, use the suited standard helpers (memzero_page(), memcpy_page()) instead of open coding kmap_local_page() plus memset() or memcpy(). Tested in a QEMU/KVM x86_32 VM, 6GB RAM, booting a kernel with HIGHMEM64GB enabled. Link: https://lkml.kernel.org/r/20220809203105.26183-3-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco Suggested-by: Ira Weiny Reviewed-by: Ira Weiny Reviewed-by: Viacheslav Dubeyko Cc: Bart Van Assche Cc: Jens Axboe Cc: Kees Cook Cc: Matthew Wilcox Cc: Muchun Song Signed-off-by: Andrew Morton

hfsplus: unmap the page in the "fail_page" label

2022-09-12T04:55:04Z

Patch series "hfsplus: Replace kmap() with kmap_local_page()". kmap() is being deprecated in favor of kmap_local_page(). There are two main problems with kmap(): (1) It comes with an overhead as mapping space is restricted and protected by a global lock for synchronization and (2) it also requires global TLB invalidation when the kmap’s pool wraps and it might block when the mapping space is fully utilized until a slot becomes available. With kmap_local_page() the mappings are per thread, CPU local, can take page faults, and can be called from any context (including interrupts). It is faster than kmap() in kernels with HIGHMEM enabled. Furthermore, the tasks can be preempted and, when they are scheduled to run again, the kernel virtual addresses are restored and still valid. Since its use in fs/hfsplus is safe everywhere, it should be preferred. Therefore, replace kmap() with kmap_local_page() in fs/hfsplus. Where possible, use the suited standard helpers (memzero_page(), memcpy_page()) instead of open coding kmap_local_page() plus memset() or memcpy(). Fix a bug due to a page being not unmapped if the code jumps to the "fail_page" label (1/4). Tested in a QEMU/KVM x86_32 VM, 6GB RAM, booting a kernel with HIGHMEM64GB enabled. This patch (of 4): Several paths within hfs_btree_open() jump to the "fail_page" label where put_page() is called while the page is still mapped. Call kunmap() to unmap the page soon before put_page(). Link: https://lkml.kernel.org/r/20220809203105.26183-1-fmdefrancesco@gmail.com Link: https://lkml.kernel.org/r/20220809203105.26183-2-fmdefrancesco@gmail.com Signed-off-by: Fabio M. De Francesco Reviewed-by: Ira Weiny Reviewed-by: Viacheslav Dubeyko Cc: Matthew Wilcox Cc: Fabio M. De Francesco Cc: Jens Axboe Cc: Bart Van Assche Cc: Kees Cook Cc: Muchun Song Signed-off-by: Andrew Morton

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

2022-08-03T17:35:43Z

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/hfsplus: Use the enum req_op and blk_opf_t types

2022-07-14T18:14:32Z

Improve static type checking by using the enum req_op type for variables that represent a request operation and the new blk_opf_t type for variables that represent request flags. Combine the last two hfsplus_submit_bio() arguments into a single argument. Cc: Christoph Hellwig Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20220714180729.1065367-55-bvanassche@acm.org Signed-off-by: Jens Axboe

hfsplus: Remove check for PageError

2022-06-29T12:51:06Z

If read_mapping_page() encounters an error, it returns an errno, not a page with PageError set, so this is dead code. Signed-off-by: Matthew Wilcox (Oracle)

fs: Change try_to_free_buffers() to take a folio

2022-05-10T03:12:34Z

All but two of the callers already have a folio; pass a folio into try_to_free_buffers(). This removes the last user of cancel_dirty_page() so remove that wrapper function too. Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Jeff Layton

hfsplus: Convert to release_folio

2022-05-10T03:12:33Z

Use a folio throughout hfsplus_release_folio(). Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Jeff Layton

fs: Convert block_read_full_page() to block_read_full_folio()

2022-05-09T20:21:44Z

This function is NOT converted to handle large folios, so include an assert that the filesystem isn't passing one in. Otherwise, use the folio functions instead of the page functions, where they exist. Convert all filesystems which use block_read_full_page(). Signed-off-by: Matthew Wilcox (Oracle)