Joseph Qi
2015-Jan-20 08:07 UTC
[Ocfs2-devel] [PATCH 4/9 v6] ocfs2: implement ocfs2_direct_IO_write
Implement ocfs2_direct_IO_write. Add the inode to orphan dir first, and
then delete it once append O_DIRECT finished.
This is to make sure block allocation and inode size are consistent.
Signed-off-by: Joseph Qi <joseph.qi at huawei.com>
Cc: Weiwei Wang <wangww631 at huawei.com>
---
fs/ocfs2/aops.c | 198 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-
fs/ocfs2/ocfs2.h | 10 +++
2 files changed, 205 insertions(+), 3 deletions(-)
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 46d93e9..8b464fe 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -28,6 +28,7 @@
#include <linux/pipe_fs_i.h>
#include <linux/mpage.h>
#include <linux/quotaops.h>
+#include <linux/blkdev.h>
#include <cluster/masklog.h>
@@ -47,6 +48,9 @@
#include "ocfs2_trace.h"
#include "buffer_head_io.h"
+#include "dir.h"
+#include "namei.h"
+#include "sysfile.h"
static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
@@ -597,6 +601,185 @@ static int ocfs2_releasepage(struct page *page, gfp_t
wait)
return try_to_free_buffers(page);
}
+static int ocfs2_is_overwrite(struct ocfs2_super *osb,
+ struct inode *inode, loff_t offset)
+{
+ int ret = 0;
+ u32 v_cpos = 0;
+ u32 p_cpos = 0;
+ unsigned int num_clusters = 0;
+ unsigned int ext_flags = 0;
+
+ v_cpos = ocfs2_bytes_to_clusters(osb->sb, offset);
+ ret = ocfs2_get_clusters(inode, v_cpos, &p_cpos,
+ &num_clusters, &ext_flags);
+ if (ret < 0) {
+ mlog_errno(ret);
+ return ret;
+ }
+
+ if (p_cpos && !(ext_flags & OCFS2_EXT_UNWRITTEN))
+ return 1;
+
+ return 0;
+}
+
+static ssize_t ocfs2_direct_IO_write(struct kiocb *iocb,
+ struct iov_iter *iter,
+ loff_t offset)
+{
+ ssize_t ret = 0;
+ ssize_t written = 0;
+ bool orphaned = false;
+ int is_overwrite = 0;
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file_inode(file)->i_mapping->host;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct buffer_head *di_bh = NULL;
+ size_t count = iter->count;
+ journal_t *journal = osb->journal->j_journal;
+ u32 zero_len;
+ int cluster_align;
+ loff_t final_size = offset + count;
+ int append_write = offset >= i_size_read(inode) ? 1 : 0;
+ unsigned int num_clusters = 0;
+ unsigned int ext_flags = 0;
+
+ {
+ u64 o = offset;
+
+ zero_len = do_div(o, 1 << osb->s_clustersize_bits);
+ cluster_align = !zero_len;
+ }
+
+ /*
+ * when final_size > inode->i_size, inode->i_size will be
+ * updated after direct write, so add the inode to orphan
+ * dir first.
+ */
+ if (final_size > i_size_read(inode)) {
+ ret = ocfs2_add_inode_to_orphan(osb, inode);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+ orphaned = true;
+ }
+
+ if (append_write) {
+ ret = ocfs2_inode_lock(inode, &di_bh, 1);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto clean_orphan;
+ }
+
+ if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)))
+ ret = ocfs2_zero_extend(inode, di_bh, offset);
+ else
+ ret = ocfs2_extend_no_holes(inode, di_bh, offset,
+ offset);
+ if (ret < 0) {
+ mlog_errno(ret);
+ ocfs2_inode_unlock(inode, 1);
+ brelse(di_bh);
+ goto clean_orphan;
+ }
+
+ is_overwrite = ocfs2_is_overwrite(osb, inode, offset);
+ if (is_overwrite < 0) {
+ mlog_errno(is_overwrite);
+ ocfs2_inode_unlock(inode, 1);
+ brelse(di_bh);
+ goto clean_orphan;
+ }
+
+ ocfs2_inode_unlock(inode, 1);
+ brelse(di_bh);
+ di_bh = NULL;
+ }
+
+ written = __blockdev_direct_IO(WRITE, iocb, inode, inode->i_sb->s_bdev,
+ iter, offset,
+ ocfs2_direct_IO_get_blocks,
+ ocfs2_dio_end_io, NULL, 0);
+ if (unlikely(written < 0)) {
+ loff_t i_size = i_size_read(inode);
+
+ if (offset + count > i_size) {
+ ret = ocfs2_inode_lock(inode, &di_bh, 1);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto clean_orphan;
+ }
+
+ if (i_size == i_size_read(inode)) {
+ ret = ocfs2_truncate_file(inode, di_bh,
+ i_size);
+ if (ret < 0) {
+ if (ret != -ENOSPC)
+ mlog_errno(ret);
+
+ ocfs2_inode_unlock(inode, 1);
+ brelse(di_bh);
+ goto clean_orphan;
+ }
+ }
+
+ ocfs2_inode_unlock(inode, 1);
+ brelse(di_bh);
+
+ ret = jbd2_journal_force_commit(journal);
+ if (ret < 0)
+ mlog_errno(ret);
+ }
+ } else if (written < 0 && append_write && !is_overwrite
&&
+ !cluster_align) {
+ u32 p_cpos = 0;
+ u32 v_cpos = ocfs2_bytes_to_clusters(osb->sb, offset);
+
+ ret = ocfs2_get_clusters(inode, v_cpos, &p_cpos,
+ &num_clusters, &ext_flags);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto clean_orphan;
+ }
+
+ BUG_ON(!p_cpos || (ext_flags & OCFS2_EXT_UNWRITTEN));
+
+ ret = blkdev_issue_zeroout(osb->sb->s_bdev,
+ p_cpos << (osb->s_clustersize_bits - 9),
+ zero_len >> 9,
+ GFP_KERNEL);
+ if (ret < 0)
+ mlog_errno(ret);
+ }
+
+clean_orphan:
+ if (orphaned) {
+ int tmp_ret;
+ int update_isize = written > 0 ? 1 : 0;
+ loff_t end = update_isize ? offset + written : 0;
+
+ tmp_ret = ocfs2_del_inode_from_orphan(osb, inode,
+ update_isize, end);
+ if (tmp_ret < 0) {
+ ret = tmp_ret;
+ goto out;
+ }
+
+ tmp_ret = jbd2_journal_force_commit(journal);
+ if (tmp_ret < 0) {
+ ret = tmp_ret;
+ mlog_errno(tmp_ret);
+ }
+ }
+
+out:
+ if (ret >= 0)
+ ret = written;
+ return ret;
+}
+
static ssize_t ocfs2_direct_IO(int rw,
struct kiocb *iocb,
struct iov_iter *iter,
@@ -604,6 +787,9 @@ static ssize_t ocfs2_direct_IO(int rw,
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file)->i_mapping->host;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ int full_coherency = !(osb->s_mount_opt &
+ OCFS2_MOUNT_COHERENCY_BUFFERED);
/*
* Fallback to buffered I/O if we see an inode without
@@ -612,14 +798,20 @@ static ssize_t ocfs2_direct_IO(int rw,
if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL)
return 0;
- /* Fallback to buffered I/O if we are appending. */
- if (i_size_read(inode) <= offset)
+ /* Fallback to buffered I/O if we are appending and
+ * concurrent O_DIRECT writes are allowed.
+ */
+ if (i_size_read(inode) <= offset && !full_coherency)
return 0;
- return __blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
+ if (rw == READ)
+ return __blockdev_direct_IO(rw, iocb, inode,
+ inode->i_sb->s_bdev,
iter, offset,
ocfs2_direct_IO_get_blocks,
ocfs2_dio_end_io, NULL, 0);
+ else
+ return ocfs2_direct_IO_write(iocb, iter, offset);
}
static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index cb1e2ec..131cc1c 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -729,6 +729,16 @@ static inline unsigned int ocfs2_clusters_for_bytes(struct
super_block *sb,
return clusters;
}
+static inline unsigned int ocfs2_bytes_to_clusters(struct super_block *sb,
+ u64 bytes)
+{
+ int cl_bits = OCFS2_SB(sb)->s_clustersize_bits;
+ unsigned int clusters;
+
+ clusters = (unsigned int)(bytes >> cl_bits);
+ return clusters;
+}
+
static inline u64 ocfs2_blocks_for_bytes(struct super_block *sb,
u64 bytes)
{
--
1.8.4.3