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authorTrond Myklebust <trond.myklebust@hammerspace.com>2021-02-08 16:55:46 +0300
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2021-02-08 19:26:14 +0300
commitfc9dc401899ab280fe1849a0ca5800384726a793 (patch)
treedd650add42ee89972be1e8c33ba41470d218373d /fs/nfs/write.c
parent37eaeed1a57e92d9db200ba7b4851a09c55eef5a (diff)
downloadlinux-fc9dc401899ab280fe1849a0ca5800384726a793.tar.xz
NFS: Optimise sparse writes past the end of file
If we're doing a write, and the entire page lies beyond the end-of-file, then we can assume the write can be extended to cover the beginning of the page, since we know the data in that region will be all zeros. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs/write.c')
-rw-r--r--fs/nfs/write.c20
1 files changed, 12 insertions, 8 deletions
diff --git a/fs/nfs/write.c b/fs/nfs/write.c
index 639c34fec04a..6193350356a8 100644
--- a/fs/nfs/write.c
+++ b/fs/nfs/write.c
@@ -1278,19 +1278,21 @@ bool nfs_ctx_key_to_expire(struct nfs_open_context *ctx, struct inode *inode)
* the PageUptodate() flag. In this case, we will need to turn off
* write optimisations that depend on the page contents being correct.
*/
-static bool nfs_write_pageuptodate(struct page *page, struct inode *inode)
+static bool nfs_write_pageuptodate(struct page *page, struct inode *inode,
+ unsigned int pagelen)
{
struct nfs_inode *nfsi = NFS_I(inode);
if (nfs_have_delegated_attributes(inode))
goto out;
- if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
+ if (nfsi->cache_validity &
+ (NFS_INO_REVAL_PAGECACHE | NFS_INO_INVALID_SIZE))
return false;
smp_rmb();
- if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags))
+ if (test_bit(NFS_INO_INVALIDATING, &nfsi->flags) && pagelen != 0)
return false;
out:
- if (nfsi->cache_validity & NFS_INO_INVALID_DATA)
+ if (nfsi->cache_validity & NFS_INO_INVALID_DATA && pagelen != 0)
return false;
return PageUptodate(page) != 0;
}
@@ -1310,7 +1312,8 @@ is_whole_file_wrlock(struct file_lock *fl)
* If the file is opened for synchronous writes then we can just skip the rest
* of the checks.
*/
-static int nfs_can_extend_write(struct file *file, struct page *page, struct inode *inode)
+static int nfs_can_extend_write(struct file *file, struct page *page,
+ struct inode *inode, unsigned int pagelen)
{
int ret;
struct file_lock_context *flctx = inode->i_flctx;
@@ -1318,7 +1321,7 @@ static int nfs_can_extend_write(struct file *file, struct page *page, struct ino
if (file->f_flags & O_DSYNC)
return 0;
- if (!nfs_write_pageuptodate(page, inode))
+ if (!nfs_write_pageuptodate(page, inode, pagelen))
return 0;
if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
return 1;
@@ -1356,6 +1359,7 @@ int nfs_updatepage(struct file *file, struct page *page,
struct nfs_open_context *ctx = nfs_file_open_context(file);
struct address_space *mapping = page_file_mapping(page);
struct inode *inode = mapping->host;
+ unsigned int pagelen = nfs_page_length(page);
int status = 0;
nfs_inc_stats(inode, NFSIOS_VFSUPDATEPAGE);
@@ -1366,8 +1370,8 @@ int nfs_updatepage(struct file *file, struct page *page,
if (!count)
goto out;
- if (nfs_can_extend_write(file, page, inode)) {
- count = max(count + offset, nfs_page_length(page));
+ if (nfs_can_extend_write(file, page, inode, pagelen)) {
+ count = max(count + offset, pagelen);
offset = 0;
}