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Message-Id: <20230324180129.1220691-2-willy@infradead.org>
Date: Fri, 24 Mar 2023 18:01:01 +0000
From: "Matthew Wilcox (Oracle)" <willy@...radead.org>
To: tytso@....edu, adilger.kernel@...ger.ca
Cc: "Matthew Wilcox (Oracle)" <willy@...radead.org>,
linux-ext4@...r.kernel.org, linux-fsdevel@...r.kernel.org
Subject: [PATCH v2 01/29] fs: Add FGP_WRITEBEGIN
This particular combination of flags is used by most filesystems
in their ->write_begin method, although it does find use in a
few other places. Before folios, it warranted its own function
(grab_cache_page_write_begin()), but I think that just having specialised
flags is enough. It certainly helps the few places that have been
converted from grab_cache_page_write_begin() to __filemap_get_folio().
Signed-off-by: Matthew Wilcox (Oracle) <willy@...radead.org>
---
fs/ext4/move_extent.c | 5 ++---
fs/iomap/buffered-io.c | 2 +-
fs/netfs/buffered_read.c | 3 +--
fs/nfs/file.c | 12 ++----------
include/linux/pagemap.h | 2 ++
mm/folio-compat.c | 4 +---
6 files changed, 9 insertions(+), 19 deletions(-)
diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
index 7bf6d069199c..a84a794fed56 100644
--- a/fs/ext4/move_extent.c
+++ b/fs/ext4/move_extent.c
@@ -126,7 +126,6 @@ mext_folio_double_lock(struct inode *inode1, struct inode *inode2,
{
struct address_space *mapping[2];
unsigned int flags;
- unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
BUG_ON(!inode1 || !inode2);
if (inode1 < inode2) {
@@ -139,14 +138,14 @@ mext_folio_double_lock(struct inode *inode1, struct inode *inode2,
}
flags = memalloc_nofs_save();
- folio[0] = __filemap_get_folio(mapping[0], index1, fgp_flags,
+ folio[0] = __filemap_get_folio(mapping[0], index1, FGP_WRITEBEGIN,
mapping_gfp_mask(mapping[0]));
if (IS_ERR(folio[0])) {
memalloc_nofs_restore(flags);
return PTR_ERR(folio[0]);
}
- folio[1] = __filemap_get_folio(mapping[1], index2, fgp_flags,
+ folio[1] = __filemap_get_folio(mapping[1], index2, FGP_WRITEBEGIN,
mapping_gfp_mask(mapping[1]));
memalloc_nofs_restore(flags);
if (IS_ERR(folio[1])) {
diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 96bb56c203f4..063133ec77f4 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -467,7 +467,7 @@ EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate);
*/
struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos)
{
- unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS;
+ unsigned fgp = FGP_WRITEBEGIN | FGP_NOFS;
if (iter->flags & IOMAP_NOWAIT)
fgp |= FGP_NOWAIT;
diff --git a/fs/netfs/buffered_read.c b/fs/netfs/buffered_read.c
index 209726a9cfdb..3404707ddbe7 100644
--- a/fs/netfs/buffered_read.c
+++ b/fs/netfs/buffered_read.c
@@ -341,14 +341,13 @@ int netfs_write_begin(struct netfs_inode *ctx,
{
struct netfs_io_request *rreq;
struct folio *folio;
- unsigned int fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
pgoff_t index = pos >> PAGE_SHIFT;
int ret;
DEFINE_READAHEAD(ractl, file, NULL, mapping, index);
retry:
- folio = __filemap_get_folio(mapping, index, fgp_flags,
+ folio = __filemap_get_folio(mapping, index, FGP_WRITEBEGIN,
mapping_gfp_mask(mapping));
if (IS_ERR(folio))
return PTR_ERR(folio);
diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 1d03406e6c03..dd9ef0655716 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -306,15 +306,6 @@ static bool nfs_want_read_modify_write(struct file *file, struct folio *folio,
return false;
}
-static struct folio *
-nfs_folio_grab_cache_write_begin(struct address_space *mapping, pgoff_t index)
-{
- unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
-
- return __filemap_get_folio(mapping, index, fgp_flags,
- mapping_gfp_mask(mapping));
-}
-
/*
* This does the "real" work of the write. We must allocate and lock the
* page to be sent back to the generic routine, which then copies the
@@ -335,7 +326,8 @@ static int nfs_write_begin(struct file *file, struct address_space *mapping,
file, mapping->host->i_ino, len, (long long) pos);
start:
- folio = nfs_folio_grab_cache_write_begin(mapping, pos >> PAGE_SHIFT);
+ folio = __filemap_get_folio(mapping, pos >> PAGE_SHIFT, FGP_WRITEBEGIN,
+ mapping_gfp_mask(mapping));
if (IS_ERR(folio))
return PTR_ERR(folio);
*pagep = &folio->page;
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index fdcd595d2294..a56308a9d1a4 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -506,6 +506,8 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping,
#define FGP_FOR_MMAP 0x00000040
#define FGP_STABLE 0x00000080
+#define FGP_WRITEBEGIN (FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE)
+
void *filemap_get_entry(struct address_space *mapping, pgoff_t index);
struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
int fgp_flags, gfp_t gfp);
diff --git a/mm/folio-compat.c b/mm/folio-compat.c
index 2511c055a35f..c6f056c20503 100644
--- a/mm/folio-compat.c
+++ b/mm/folio-compat.c
@@ -106,9 +106,7 @@ EXPORT_SYMBOL(pagecache_get_page);
struct page *grab_cache_page_write_begin(struct address_space *mapping,
pgoff_t index)
{
- unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
-
- return pagecache_get_page(mapping, index, fgp_flags,
+ return pagecache_get_page(mapping, index, FGP_WRITEBEGIN,
mapping_gfp_mask(mapping));
}
EXPORT_SYMBOL(grab_cache_page_write_begin);
--
2.39.2
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