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authorMatthew Wilcox (Oracle) <willy@infradead.org>2020-10-16 05:06:28 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-16 20:11:16 +0200
commitfefa7c478fdafe71c64b5ddf817ac0271aed1146 (patch)
tree2914f3ee4ad601b510eefa45885fe15d3fd9ddb8 /mm/readahead.c
parentmm/readahead: pass readahead_control to force_page_cache_ra (diff)
downloadlinux-fefa7c478fdafe71c64b5ddf817ac0271aed1146.tar.xz
linux-fefa7c478fdafe71c64b5ddf817ac0271aed1146.zip
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.c58
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)
{