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 <[email protected]> --- fs/cifs/cifsfs.c | 44 ++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 42 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 9c37897..370acdc 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -568,6 +568,46 @@ 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 = 0, retval; + unsigned long i; + + 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. + */ + + for (i = 0; i < nr_segs; i++) { + retval = cifs_user_read(iocb->ki_filp, iov[i].iov_base, + iov[i].iov_len, &pos); + if (retval < 0) { + read = read ? read : retval; + break; + } + + read += retval; + } + + 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 +730,7 @@ 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 +767,7 @@ 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, -- 1.7.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
