| Message ID | 5439234B.2030709@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2014/10/11 20:32, WeiWei Wang wrote: > Now append O_DIRECT write to a hole will try direct io first, then > fallback to buffered IO if fails. > > Signed-off-by: Weiwei Wang <wangww631@huawei.com> > Reviewed-by: Joseph Qi <joseph.qi@huawei.com> > --- > fs/ocfs2/file.c | 93 ++++++++++++++++++++++++++------------------------------- > 1 file changed, 42 insertions(+), 51 deletions(-) > > diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c > index 19e372f..08f234e 100644 > --- a/fs/ocfs2/file.c > +++ b/fs/ocfs2/file.c > @@ -1353,44 +1353,6 @@ out: > return ret; > } > > -/* > - * Will look for holes and unwritten extents in the range starting at > - * pos for count bytes (inclusive). > - */ > -static int ocfs2_check_range_for_holes(struct inode *inode, loff_t pos, > - size_t count) > -{ > - int ret = 0; > - unsigned int extent_flags; > - u32 cpos, clusters, extent_len, phys_cpos; > - struct super_block *sb = inode->i_sb; > - > - cpos = pos >> OCFS2_SB(sb)->s_clustersize_bits; > - clusters = ocfs2_clusters_for_bytes(sb, pos + count) - cpos; > - > - while (clusters) { > - ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len, > - &extent_flags); > - if (ret < 0) { > - mlog_errno(ret); > - goto out; > - } > - > - if (phys_cpos == 0 || (extent_flags & OCFS2_EXT_UNWRITTEN)) { > - ret = 1; > - break; > - } > - > - if (extent_len > clusters) > - extent_len = clusters; > - > - clusters -= extent_len; > - cpos += extent_len; > - } > -out: > - return ret; > -} > - > static int ocfs2_write_remove_suid(struct inode *inode) > { > int ret; > @@ -2206,18 +2168,6 @@ static int ocfs2_prepare_inode_for_write(struct file *file, > break; > } > > - /* > - * We don't fill holes during direct io, so > - * check for them here. If any are found, the > - * caller will have to retake some cluster > - * locks and initiate the io as buffered. > - */ > - ret = ocfs2_check_range_for_holes(inode, saved_pos, count); > - if (ret == 1) { > - *direct_io = 0; > - ret = 0; > - } else if (ret < 0) > - mlog_errno(ret); > break; > } > > @@ -2247,6 +2197,7 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb, > u32 old_clusters; > struct file *file = iocb->ki_filp; > struct inode *inode = file_inode(file); > + struct address_space *mapping = file->f_mapping; > struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); > int full_coherency = !(osb->s_mount_opt & > OCFS2_MOUNT_COHERENCY_BUFFERED); > @@ -2361,11 +2312,51 @@ relock: > > iov_iter_truncate(from, count); > if (direct_io) { > + loff_t endbyte; > + ssize_t written_buffered; > written = generic_file_direct_write(iocb, from, *ppos); > - if (written < 0) { > + if (written < 0 || written == count) { > ret = written; > goto out_dio; > } > + /* > + * direct-io write to a hole: fall through to buffered I/O > + * for completing the rest of the request. > + */ > + *ppos += written; Here *ppos has already been changed in generic_file_direct_write. > + count -= written; > + written_buffered = generic_perform_write(file, from, *ppos); > + /* > + * If generic_file_buffered_write() retuned a synchronous error > + * then we want to return the number of bytes which were > + * direct-written, or the error code if that was zero. Note > + * that this differs from normal direct-io semantics, which > + * will return -EFOO even if some bytes were written. > + */ > + if (written_buffered < 0) { > + ret = written_buffered; > + goto out; > + } > + > + /* > + * We need to ensure that the page cache pages are written to > + * disk and invalidated to preserve the expected O_DIRECT > + * semantics. > + */ > + endbyte = *ppos + written_buffered - written - 1; > + ret = filemap_write_and_wait_range(file->f_mapping, *ppos, > + endbyte); > + if (ret == 0) { > + written = written_buffered; > + invalidate_mapping_pages(mapping, > + *ppos >> PAGE_CACHE_SHIFT, > + endbyte >> PAGE_CACHE_SHIFT); > + } else { > + /* > + * We don't know how much we wrote, so just return > + * the number of bytes which were direct-written > + */ > + } > } else { > current->backing_dev_info = file->f_mapping->backing_dev_info; > written = generic_perform_write(file, from, *ppos); >
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 19e372f..08f234e 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1353,44 +1353,6 @@ out: return ret; } -/* - * Will look for holes and unwritten extents in the range starting at - * pos for count bytes (inclusive). - */ -static int ocfs2_check_range_for_holes(struct inode *inode, loff_t pos, - size_t count) -{ - int ret = 0; - unsigned int extent_flags; - u32 cpos, clusters, extent_len, phys_cpos; - struct super_block *sb = inode->i_sb; - - cpos = pos >> OCFS2_SB(sb)->s_clustersize_bits; - clusters = ocfs2_clusters_for_bytes(sb, pos + count) - cpos; - - while (clusters) { - ret = ocfs2_get_clusters(inode, cpos, &phys_cpos, &extent_len, - &extent_flags); - if (ret < 0) { - mlog_errno(ret); - goto out; - } - - if (phys_cpos == 0 || (extent_flags & OCFS2_EXT_UNWRITTEN)) { - ret = 1; - break; - } - - if (extent_len > clusters) - extent_len = clusters; - - clusters -= extent_len; - cpos += extent_len; - } -out: - return ret; -} - static int ocfs2_write_remove_suid(struct inode *inode) { int ret; @@ -2206,18 +2168,6 @@ static int ocfs2_prepare_inode_for_write(struct file *file, break; } - /* - * We don't fill holes during direct io, so - * check for them here. If any are found, the - * caller will have to retake some cluster - * locks and initiate the io as buffered. - */ - ret = ocfs2_check_range_for_holes(inode, saved_pos, count); - if (ret == 1) { - *direct_io = 0; - ret = 0; - } else if (ret < 0) - mlog_errno(ret); break; } @@ -2247,6 +2197,7 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb, u32 old_clusters; struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); + struct address_space *mapping = file->f_mapping; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); int full_coherency = !(osb->s_mount_opt & OCFS2_MOUNT_COHERENCY_BUFFERED); @@ -2361,11 +2312,51 @@ relock: iov_iter_truncate(from, count); if (direct_io) { + loff_t endbyte; + ssize_t written_buffered; written = generic_file_direct_write(iocb, from, *ppos); - if (written < 0) { + if (written < 0 || written == count) { ret = written; goto out_dio; } + /* + * direct-io write to a hole: fall through to buffered I/O + * for completing the rest of the request. + */ + *ppos += written; + count -= written; + written_buffered = generic_perform_write(file, from, *ppos); + /* + * If generic_file_buffered_write() retuned a synchronous error + * then we want to return the number of bytes which were + * direct-written, or the error code if that was zero. Note + * that this differs from normal direct-io semantics, which + * will return -EFOO even if some bytes were written. + */ + if (written_buffered < 0) { + ret = written_buffered; + goto out; + } + + /* + * We need to ensure that the page cache pages are written to + * disk and invalidated to preserve the expected O_DIRECT + * semantics. + */ + endbyte = *ppos + written_buffered - written - 1; + ret = filemap_write_and_wait_range(file->f_mapping, *ppos, + endbyte); + if (ret == 0) { + written = written_buffered; + invalidate_mapping_pages(mapping, + *ppos >> PAGE_CACHE_SHIFT, + endbyte >> PAGE_CACHE_SHIFT); + } else { + /* + * We don't know how much we wrote, so just return + * the number of bytes which were direct-written + */ + } } else { current->backing_dev_info = file->f_mapping->backing_dev_info; written = generic_perform_write(file, from, *ppos);