summaryrefslogtreecommitdiff
path: root/mm
diff options
context:
space:
mode:
authorMatthew Wilcox (Oracle) <willy@infradead.org>2020-12-24 12:55:56 -0500
committerMatthew Wilcox (Oracle) <willy@infradead.org>2021-10-18 07:49:41 -0400
commitb27652d935f41793c5e229a1e8b3a8bb3afe3cc1 (patch)
treed0a5062b4845c54721f9d99d653e85c78f2e2324 /mm
parent3f0c6a07fee6a1c2618a2e12ffb8e9aa24384fde (diff)
mm/filemap: Add FGP_STABLE
Allow filemap_get_folio() to wait for writeback to complete (if the filesystem wants that behaviour). This is the folio equivalent of grab_cache_page_write_begin(), which is moved into the folio-compat file as a reminder to migrate all the code using it. This paves the way for getting rid of AOP_FLAG_NOFS once grab_cache_page_write_begin() is removed. Kernel grows by 11 bytes. filemap_get_folio() grows by 33 bytes but grab_cache_page_write_begin() shrinks by 22 bytes to make up for it. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Reviewed-by: David Howells <dhowells@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz>
Diffstat (limited to 'mm')
-rw-r--r--mm/filemap.c25
-rw-r--r--mm/folio-compat.c13
2 files changed, 16 insertions, 22 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index de4cc1b9aa9b..3e9feb5cc570 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1872,6 +1872,7 @@ out:
* * %FGP_WRITE - The page will be written to by the caller.
* * %FGP_NOFS - __GFP_FS will get cleared in gfp.
* * %FGP_NOWAIT - Don't get blocked by page lock.
+ * * %FGP_STABLE - Wait for the folio to be stable (finished writeback)
*
* If %FGP_LOCK or %FGP_CREAT are specified then the function may sleep even
* if the %GFP flags specified for %FGP_CREAT are atomic.
@@ -1922,6 +1923,8 @@ repeat:
folio_clear_idle(folio);
}
+ if (fgp_flags & FGP_STABLE)
+ folio_wait_stable(folio);
no_page:
if (!folio && (fgp_flags & FGP_CREAT)) {
int err;
@@ -3704,28 +3707,6 @@ out:
}
EXPORT_SYMBOL(generic_file_direct_write);
-/*
- * Find or create a page at the given pagecache position. Return the locked
- * page. This function is specifically for buffered writes.
- */
-struct page *grab_cache_page_write_begin(struct address_space *mapping,
- pgoff_t index, unsigned flags)
-{
- struct page *page;
- int fgp_flags = FGP_LOCK|FGP_WRITE|FGP_CREAT;
-
- if (flags & AOP_FLAG_NOFS)
- fgp_flags |= FGP_NOFS;
-
- page = pagecache_get_page(mapping, index, fgp_flags,
- mapping_gfp_mask(mapping));
- if (page)
- wait_for_stable_page(page);
-
- return page;
-}
-EXPORT_SYMBOL(grab_cache_page_write_begin);
-
ssize_t generic_perform_write(struct file *file,
struct iov_iter *i, loff_t pos)
{
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index e833e680e944..5b6ae1da314e 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -116,6 +116,7 @@ int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
}
EXPORT_SYMBOL(add_to_page_cache_lru);
+noinline
struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
int fgp_flags, gfp_t gfp)
{
@@ -127,3 +128,15 @@ struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
return folio_file_page(folio, index);
}
EXPORT_SYMBOL(pagecache_get_page);
+
+struct page *grab_cache_page_write_begin(struct address_space *mapping,
+ pgoff_t index, unsigned flags)
+{
+ unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
+
+ if (flags & AOP_FLAG_NOFS)
+ fgp_flags |= FGP_NOFS;
+ return pagecache_get_page(mapping, index, fgp_flags,
+ mapping_gfp_mask(mapping));
+}
+EXPORT_SYMBOL(grab_cache_page_write_begin);