The patch titled
mm: introduce probe_page()
has been added to the -mm tree. Its filename is
mm-introduce-probe_page.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: mm: introduce probe_page()
From: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
Introduce a pair of functions to probe the existence of file page.
- int __probe_page(mapping, offset)
- int probe_page(mapping, offset)
Signed-off-by: Wu Fengguang <wfg@xxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/pagemap.h | 2 ++
mm/filemap.c | 23 +++++++++++++++++++++++
2 files changed, 25 insertions(+)
diff -puN include/linux/pagemap.h~mm-introduce-probe_page include/linux/pagemap.h
--- a/include/linux/pagemap.h~mm-introduce-probe_page
+++ a/include/linux/pagemap.h
@@ -72,6 +72,8 @@ static inline struct page *page_cache_al
typedef int filler_t(void *, struct page *);
+extern int __probe_page(struct address_space *mapping, pgoff_t offset);
+extern int probe_page(struct address_space *mapping, pgoff_t offset);
extern struct page * find_get_page(struct address_space *mapping,
unsigned long index);
extern struct page * find_lock_page(struct address_space *mapping,
diff -puN mm/filemap.c~mm-introduce-probe_page mm/filemap.c
--- a/mm/filemap.c~mm-introduce-probe_page
+++ a/mm/filemap.c
@@ -584,6 +584,29 @@ void fastcall __lock_page_nosync(struct
TASK_UNINTERRUPTIBLE);
}
+/*
+ * Probing page existence.
+ */
+int __probe_page(struct address_space *mapping, pgoff_t offset)
+{
+ return !!radix_tree_lookup(&mapping->page_tree, offset);
+}
+
+/*
+ * Here we just do not bother to grab the page, it's meaningless anyway.
+ */
+int probe_page(struct address_space *mapping, pgoff_t offset)
+{
+ int exists;
+
+ read_lock_irq(&mapping->tree_lock);
+ exists = __probe_page(mapping, offset);
+ read_unlock_irq(&mapping->tree_lock);
+
+ return exists;
+}
+EXPORT_SYMBOL(probe_page);
+
/**
* find_get_page - find and get a page reference
* @mapping: the address_space to search
_
Patches currently in -mm which might be from wfg@xxxxxxxxxxxxxxxx are
readahead-kconfig-options.patch
radixtree-introduce-scan-hole-data-functions.patch
mm-introduce-probe_page.patch
mm-introduce-pg_readahead.patch
readahead-add-look-ahead-support-to-__do_page_cache_readahead.patch
readahead-insert-cond_resched-calls.patch
readahead-minmax_ra_pages.patch
readahead-events-accounting.patch
readahead-rescue_pages.patch
readahead-sysctl-parameters.patch
readahead-min-max-sizes.patch
readahead-state-based-method-aging-accounting.patch
readahead-state-based-method-routines.patch
readahead-state-based-method.patch
readahead-context-based-method.patch
readahead-initial-method-guiding-sizes.patch
readahead-initial-method-thrashing-guard-size.patch
readahead-initial-method-user-recommended-size.patch
readahead-initial-method.patch
readahead-backward-prefetching-method.patch
readahead-thrashing-recovery-method.patch
readahead-call-scheme.patch
readahead-laptop-mode.patch
readahead-loop-case.patch
readahead-nfsd-case.patch
readahead-turn-on-by-default.patch
readahead-remove-size-limit-on-read_ahead_kb.patch
readahead-remove-size-limit-of-max_sectors_kb-on-read_ahead_kb.patch
-
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