Commit 7e7f7749 authored by Ross Zwisler's avatar Ross Zwisler Committed by Linus Torvalds

mm: add find_get_entries_tag()

Add find_get_entries_tag() to the family of functions that include
find_get_entries(), find_get_pages() and find_get_pages_tag().  This is
needed for DAX dirty page handling because we need a list of both page
offsets and radix tree entries ('indices' and 'entries' in this
function) that are marked with the PAGECACHE_TAG_TOWRITE tag.
Signed-off-by: default avatarRoss Zwisler <>
Reviewed-by: default avatarJan Kara <>
Cc: "H. Peter Anvin" <>
Cc: "J. Bruce Fields" <>
Cc: "Theodore Ts'o" <>
Cc: Alexander Viro <>
Cc: Andreas Dilger <>
Cc: Dave Chinner <>
Cc: Ingo Molnar <>
Cc: Jeff Layton <>
Cc: Matthew Wilcox <>
Cc: Thomas Gleixner <>
Cc: Dan Williams <>
Cc: Matthew Wilcox <>
Cc: Dave Hansen <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
parent f9fe48be
......@@ -361,6 +361,9 @@ unsigned find_get_pages_contig(struct address_space *mapping, pgoff_t start,
unsigned int nr_pages, struct page **pages);
unsigned find_get_pages_tag(struct address_space *mapping, pgoff_t *index,
int tag, unsigned int nr_pages, struct page **pages);
unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start,
int tag, unsigned int nr_entries,
struct page **entries, pgoff_t *indices);
struct page *grab_cache_page_write_begin(struct address_space *mapping,
pgoff_t index, unsigned flags);
......@@ -1499,6 +1499,74 @@ repeat:
* find_get_entries_tag - find and return entries that match @tag
* @mapping: the address_space to search
* @start: the starting page cache index
* @tag: the tag index
* @nr_entries: the maximum number of entries
* @entries: where the resulting entries are placed
* @indices: the cache indices corresponding to the entries in @entries
* Like find_get_entries, except we only return entries which are tagged with
* @tag.
unsigned find_get_entries_tag(struct address_space *mapping, pgoff_t start,
int tag, unsigned int nr_entries,
struct page **entries, pgoff_t *indices)
void **slot;
unsigned int ret = 0;
struct radix_tree_iter iter;
if (!nr_entries)
return 0;
radix_tree_for_each_tagged(slot, &mapping->page_tree,
&iter, start, tag) {
struct page *page;
page = radix_tree_deref_slot(slot);
if (unlikely(!page))
if (radix_tree_exception(page)) {
if (radix_tree_deref_retry(page)) {
* Transient condition which can only trigger
* when entry at index 0 moves out of or back
* to root: none yet gotten, safe to restart.
goto restart;
* A shadow entry of a recently evicted page, a swap
* entry from shmem/tmpfs or a DAX entry. Return it
* without attempting to raise page count.
goto export;
if (!page_cache_get_speculative(page))
goto repeat;
/* Has the page moved? */
if (unlikely(page != *slot)) {
goto repeat;
indices[ret] = iter.index;
entries[ret] = page;
if (++ret == nr_entries)
return ret;
* CD/DVDs are error prone. When a medium error occurs, the driver may fail
* a _large_ part of the i/o request. Imagine the worst scenario:
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