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author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-19 14:28:30 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-19 14:28:30 -0700 |
commit | 694565356c2e06224d94774a42709cc8dfab49ee (patch) | |
tree | 443d7b3b08166603b435670dff18fdf203048171 /fs/dax.c | |
parent | 922a763ae178901c2393424ba42b0aa1be22bf06 (diff) | |
parent | 42d3e2d041f08d1f8f078da005c936648ba77405 (diff) | |
download | linux-694565356c2e06224d94774a42709cc8dfab49ee.tar.gz |
Merge tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi: - Support directly accessing host page cache from virtiofs. This can improve I/O performance for various workloads, as well as reducing the memory requirement by eliminating double caching. Thanks to Vivek Goyal for doing most of the work on this. - Allow automatic submounting inside virtiofs. This allows unique st_dev/ st_ino values to be assigned inside the guest to files residing on different filesystems on the host. Thanks to Max Reitz for the patches. - Fix an old use after free bug found by Pradeep P V K. * tag 'fuse-update-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (25 commits) virtiofs: calculate number of scatter-gather elements accurately fuse: connection remove fix fuse: implement crossmounts fuse: Allow fuse_fill_super_common() for submounts fuse: split fuse_mount off of fuse_conn fuse: drop fuse_conn parameter where possible fuse: store fuse_conn in fuse_req fuse: add submount support to <uapi/linux/fuse.h> fuse: fix page dereference after free virtiofs: add logic to free up a memory range virtiofs: maintain a list of busy elements virtiofs: serialize truncate/punch_hole and dax fault path virtiofs: define dax address space operations virtiofs: add DAX mmap support virtiofs: implement dax read/write operations virtiofs: introduce setupmapping/removemapping commands virtiofs: implement FUSE_INIT map_alignment field virtiofs: keep a list of free dax memory ranges virtiofs: add a mount option to enable dax virtiofs: set up virtio_fs dax_device ...
Diffstat (limited to 'fs/dax.c')
-rw-r--r-- | fs/dax.c | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/fs/dax.c b/fs/dax.c index 6ad346352a8c..5b47834f2e1b 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -559,8 +559,11 @@ fallback: } /** - * dax_layout_busy_page - find first pinned page in @mapping + * dax_layout_busy_page_range - find first pinned page in @mapping * @mapping: address space to scan for a page with ref count > 1 + * @start: Starting offset. Page containing 'start' is included. + * @end: End offset. Page containing 'end' is included. If 'end' is LLONG_MAX, + * pages from 'start' till the end of file are included. * * DAX requires ZONE_DEVICE mapped pages. These pages are never * 'onlined' to the page allocator so they are considered idle when @@ -573,12 +576,15 @@ fallback: * to be able to run unmap_mapping_range() and subsequently not race * mapping_mapped() becoming true. */ -struct page *dax_layout_busy_page(struct address_space *mapping) +struct page *dax_layout_busy_page_range(struct address_space *mapping, + loff_t start, loff_t end) { - XA_STATE(xas, &mapping->i_pages, 0); void *entry; unsigned int scanned = 0; struct page *page = NULL; + pgoff_t start_idx = start >> PAGE_SHIFT; + pgoff_t end_idx; + XA_STATE(xas, &mapping->i_pages, start_idx); /* * In the 'limited' case get_user_pages() for dax is disabled. @@ -589,6 +595,11 @@ struct page *dax_layout_busy_page(struct address_space *mapping) if (!dax_mapping(mapping) || !mapping_mapped(mapping)) return NULL; + /* If end == LLONG_MAX, all pages from start to till end of file */ + if (end == LLONG_MAX) + end_idx = ULONG_MAX; + else + end_idx = end >> PAGE_SHIFT; /* * If we race get_user_pages_fast() here either we'll see the * elevated page count in the iteration and wait, or @@ -596,15 +607,15 @@ struct page *dax_layout_busy_page(struct address_space *mapping) * against is no longer mapped in the page tables and bail to the * get_user_pages() slow path. The slow path is protected by * pte_lock() and pmd_lock(). New references are not taken without - * holding those locks, and unmap_mapping_range() will not zero the + * holding those locks, and unmap_mapping_pages() will not zero the * pte or pmd without holding the respective lock, so we are * guaranteed to either see new references or prevent new * references from being established. */ - unmap_mapping_range(mapping, 0, 0, 0); + unmap_mapping_pages(mapping, start_idx, end_idx - start_idx + 1, 0); xas_lock_irq(&xas); - xas_for_each(&xas, entry, ULONG_MAX) { + xas_for_each(&xas, entry, end_idx) { if (WARN_ON_ONCE(!xa_is_value(entry))) continue; if (unlikely(dax_is_locked(entry))) @@ -625,6 +636,12 @@ struct page *dax_layout_busy_page(struct address_space *mapping) xas_unlock_irq(&xas); return page; } +EXPORT_SYMBOL_GPL(dax_layout_busy_page_range); + +struct page *dax_layout_busy_page(struct address_space *mapping) +{ + return dax_layout_busy_page_range(mapping, 0, LLONG_MAX); +} EXPORT_SYMBOL_GPL(dax_layout_busy_page); static int __dax_invalidate_entry(struct address_space *mapping, |