diff options
author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2020-10-15 20:06:28 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-16 11:11:16 -0700 |
commit | fefa7c478fdafe71c64b5ddf817ac0271aed1146 (patch) | |
tree | 2914f3ee4ad601b510eefa45885fe15d3fd9ddb8 /mm/readahead.c | |
parent | 7b3df3b9ac7e807bf1b6fcc03077bd80068f3d3c (diff) |
mm/readahead: add page_cache_sync_ra and page_cache_async_ra
Reimplement page_cache_sync_readahead() and page_cache_async_readahead()
as wrappers around versions of the function which take a readahead_control
in preparation for making do_sync_mmap_readahead() pass down an RAC
struct.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Eric Biggers <ebiggers@google.com>
Link: https://lkml.kernel.org/r/20200903140844.14194-8-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/readahead.c')
-rw-r--r-- | mm/readahead.c | 58 |
1 files changed, 12 insertions, 46 deletions
diff --git a/mm/readahead.c b/mm/readahead.c index 3115ced5faae..620ac83f35cc 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -550,25 +550,9 @@ readit: do_page_cache_ra(ractl, ra->size, ra->async_size); } -/** - * page_cache_sync_readahead - generic file readahead - * @mapping: address_space which holds the pagecache and I/O vectors - * @ra: file_ra_state which holds the readahead state - * @filp: passed on to ->readpage() and ->readpages() - * @index: Index of first page to be read. - * @req_count: Total number of pages being read by the caller. - * - * page_cache_sync_readahead() should be called when a cache miss happened: - * it will submit the read. The readahead logic may decide to piggyback more - * pages onto the read request if access patterns suggest it will improve - * performance. - */ -void page_cache_sync_readahead(struct address_space *mapping, - struct file_ra_state *ra, struct file *filp, - pgoff_t index, unsigned long req_count) +void page_cache_sync_ra(struct readahead_control *ractl, + struct file_ra_state *ra, unsigned long req_count) { - DEFINE_READAHEAD(ractl, filp, mapping, index); - /* no read-ahead */ if (!ra->ra_pages) return; @@ -577,38 +561,20 @@ void page_cache_sync_readahead(struct address_space *mapping, return; /* be dumb */ - if (filp && (filp->f_mode & FMODE_RANDOM)) { - force_page_cache_ra(&ractl, req_count); + if (ractl->file && (ractl->file->f_mode & FMODE_RANDOM)) { + force_page_cache_ra(ractl, req_count); return; } /* do read-ahead */ - ondemand_readahead(&ractl, ra, false, req_count); + ondemand_readahead(ractl, ra, false, req_count); } -EXPORT_SYMBOL_GPL(page_cache_sync_readahead); +EXPORT_SYMBOL_GPL(page_cache_sync_ra); -/** - * page_cache_async_readahead - file readahead for marked pages - * @mapping: address_space which holds the pagecache and I/O vectors - * @ra: file_ra_state which holds the readahead state - * @filp: passed on to ->readpage() and ->readpages() - * @page: The page at @index which triggered the readahead call. - * @index: Index of first page to be read. - * @req_count: Total number of pages being read by the caller. - * - * page_cache_async_readahead() should be called when a page is used which - * is marked as PageReadahead; this is a marker to suggest that the application - * has used up enough of the readahead window that we should start pulling in - * more pages. - */ -void -page_cache_async_readahead(struct address_space *mapping, - struct file_ra_state *ra, struct file *filp, - struct page *page, pgoff_t index, - unsigned long req_count) +void page_cache_async_ra(struct readahead_control *ractl, + struct file_ra_state *ra, struct page *page, + unsigned long req_count) { - DEFINE_READAHEAD(ractl, filp, mapping, index); - /* no read-ahead */ if (!ra->ra_pages) return; @@ -624,16 +590,16 @@ page_cache_async_readahead(struct address_space *mapping, /* * Defer asynchronous read-ahead on IO congestion. */ - if (inode_read_congested(mapping->host)) + if (inode_read_congested(ractl->mapping->host)) return; if (blk_cgroup_congested()) return; /* do read-ahead */ - ondemand_readahead(&ractl, ra, true, req_count); + ondemand_readahead(ractl, ra, true, req_count); } -EXPORT_SYMBOL_GPL(page_cache_async_readahead); +EXPORT_SYMBOL_GPL(page_cache_async_ra); ssize_t ksys_readahead(int fd, loff_t offset, size_t count) { |