Add cifs_file_aio_read where we read from the cache if we have at least
Level II oplock - otherwise read from the server.
Signed-off-by: Pavel Shilovsky <piastryyy@xxxxxxxxx>
---
fs/cifs/cifsfs.c | 31 +++++++++++++++++++++++++++++--
1 files changed, 29 insertions(+), 2 deletions(-)
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 9c37897..bbb5294 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -568,6 +568,33 @@ cifs_do_mount(struct file_system_type *fs_type,
return dget(sb->s_root);
}
+static ssize_t cifs_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ struct inode *inode;
+ struct cifs_sb_info *cifs_sb;
+ ssize_t read;
+
+ inode = iocb->ki_filp->f_path.dentry->d_inode;
+ cifs_sb = CIFS_SB(iocb->ki_filp->f_path.dentry->d_sb);
+
+ if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) == 0 ||
+ CIFS_I(inode)->clientCanCacheRead)
+ return generic_file_aio_read(iocb, iov, nr_segs, pos);
+
+ /* in strict cache mode we need to read from the server all the time
+ if we don't have level II oplock because the server can delay mtime
+ change - so we can't make a decision about inode invalidating.
+ And we can also fail with pagereading if there are mandatory locks
+ on pages affected by this read but not on the region from pos to
+ pos+len-1 */
+ read = cifs_user_read(iocb->ki_filp, iov->iov_base,
+ iov->iov_len, &pos);
+ iocb->ki_pos = pos;
+
+ return read;
+}
+
static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
@@ -690,7 +717,7 @@ const struct inode_operations cifs_symlink_inode_ops = {
const struct file_operations cifs_file_ops = {
.read = do_sync_read,
.write = do_sync_write,
- .aio_read = generic_file_aio_read,
+ .aio_read = cifs_file_aio_read,
.aio_write = cifs_file_aio_write,
.open = cifs_open,
.release = cifs_close,
@@ -727,7 +754,7 @@ const struct file_operations cifs_file_direct_ops = {
const struct file_operations cifs_file_nobrl_ops = {
.read = do_sync_read,
.write = do_sync_write,
- .aio_read = generic_file_aio_read,
+ .aio_read = cifs_file_aio_read,
.aio_write = cifs_file_aio_write,
.open = cifs_open,
.release = cifs_close,
--
1.7.2.3
--
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