On Tue, 2 Nov 2010 12:02:24 +0300 Pavel Shilovsky <[email protected]> wrote:
> Modify cifs_file_aio_write and cifs_write_end to let the client works with > strict cache mode. > > Signed-off-by: Pavel Shilovsky <[email protected]> > --- > fs/cifs/cifsfs.c | 35 ++++++++++++++++++++++++++++++----- > fs/cifs/file.c | 14 ++++++++++++-- > 2 files changed, 42 insertions(+), 7 deletions(-) > > diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c > index 1b44a92..e1ecd35 100644 > --- a/fs/cifs/cifsfs.c > +++ b/fs/cifs/cifsfs.c > @@ -602,12 +602,37 @@ static ssize_t cifs_file_aio_read(struct kiocb > *iocb, const struct iovec *iov, > static ssize_t cifs_file_aio_write(struct kiocb *iocb, const struct iovec > *iov, > unsigned long nr_segs, loff_t pos) > { > - struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode; > - ssize_t written; > + struct inode *inode; > + struct cifs_sb_info *cifs_sb; > + ssize_t written, cache_written; > + loff_t saved_pos; > + > + inode = iocb->ki_filp->f_path.dentry->d_inode; > + > + if (CIFS_I(inode)->clientCanCacheAll) > + return generic_file_aio_write(iocb, iov, nr_segs, pos); > + > + cifs_sb = CIFS_SB(iocb->ki_filp->f_path.dentry->d_sb); > + > + if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) == 0) { > + written = generic_file_aio_write(iocb, iov, nr_segs, pos); > + filemap_write_and_wait(inode->i_mapping); ^^^^^^^^^^^^^^^^^^ You can't ignore the return code from this. That function may return an error if writeback fails. Also, I don't see any need to wait on the result in this case. Why not just kick off the I/O and return (do a filemap_fdatawrite, IOW). > + return written; > + } > + > + saved_pos = pos; > + written = cifs_user_write(iocb->ki_filp, iov->iov_base, > + iov->iov_len, &pos); > + > + if (written > 0) { > + cache_written = generic_file_aio_write(iocb, iov, > + nr_segs, saved_pos); > + if (cache_written != written) > + cERROR(1, "Cache written and server written data " > + "lengths are different"); > + } else > + iocb->ki_pos = pos; > ^^^^^ This seems awfully complicated. Why not just do a generic_file_aio_write to get this into the cache and then just do a filemap_write_and_wait and deal with the result? > - written = generic_file_aio_write(iocb, iov, nr_segs, pos); > - if (!CIFS_I(inode)->clientCanCacheAll) > - filemap_fdatawrite(inode->i_mapping); > return written; > } > > diff --git a/fs/cifs/file.c b/fs/cifs/file.c > index 3970e68..4796748 100644 > --- a/fs/cifs/file.c > +++ b/fs/cifs/file.c > @@ -1539,7 +1539,11 @@ static int cifs_write_end(struct file *file, > struct address_space *mapping, > struct page *page, void *fsdata) > { > int rc; > - struct inode *inode = mapping->host; > + struct inode *inode; > + struct cifs_sb_info *cifs_sb; > + > + inode = mapping->host; > + cifs_sb = CIFS_SB(inode->i_sb); > > cFYI(1, "write_end for page %p from pos %lld with %d bytes", > page, pos, copied); > @@ -1572,7 +1576,13 @@ static int cifs_write_end(struct file *file, > struct address_space *mapping, > } else { > rc = copied; > pos += copied; > - set_page_dirty(page); > + /* if we have strict cache switched on and don't have Exclusive > + oplock for the inode, we don't have to set_page_dirty > + because we flushed the data to the server in > + cifs_file_aio_write before */ > + if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO) == 0 || > + CIFS_I(inode)->clientCanCacheAll) > + set_page_dirty(page); > } > > if (rc > 0) { -- Jeff Layton <[email protected]> -- 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
