[PATCH v2] f2fs: compress: don't force buffered io when in COMPR_MODE_USER mode

[Yangtao Li]

It is observed that when in user compression mode (compress_extension=*),
even though the file is not compressed, the file is still forced to use
buffer io, which makes the AndroBench sequential read and write drop
significantly. In fact, when the file is not compressed, we don't need
to force it to buffer io.

                 | w/o patch | w/ patch |
seq read  (MB/s) | 1320.068  | 3696.154 |
seq write (MB/s) | 617.996   | 2978.478 |

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Qi Han <hanqi@xxxxxxxx>
Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>
---
 fs/f2fs/f2fs.h | 14 ++++++++++++++
 fs/f2fs/file.c |  5 ++++-
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 3f5b161dd743..9e960f1a1117 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3170,6 +3170,20 @@ static inline int f2fs_compressed_file(struct inode *inode)
 		is_inode_flag_set(inode, FI_COMPRESSED_FILE);
 }
 
+static inline bool f2fs_is_compressed_file(struct inode *inode)
+{
+	int compress_mode = F2FS_OPTION(F2FS_I_SB(inode)).compress_mode;
+
+	if (compress_mode == COMPR_MODE_FS)
+		return f2fs_compressed_file(inode);
+	else if (atomic_read(&F2FS_I(inode)->i_compr_blocks) ||
+		is_inode_flag_set(inode, FI_COMPRESS_RELEASED) ||
+		is_inode_flag_set(inode, FI_ENABLE_COMPRESS))
+		return true;
+
+	return false;
+}
+
 static inline bool f2fs_need_compress_data(struct inode *inode)
 {
 	int compress_mode = F2FS_OPTION(F2FS_I_SB(inode)).compress_mode;
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index f45d05c13ae5..75c9c3327bbd 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -822,7 +822,7 @@ static bool f2fs_force_buffered_io(struct inode *inode, int rw)
 		return true;
 	if (fsverity_active(inode))
 		return true;
-	if (f2fs_compressed_file(inode))
+	if (f2fs_is_compressed_file(inode))
 		return true;
 
 	/* disallow direct IO if any of devices has unaligned blksize */
@@ -4146,6 +4146,9 @@ static int f2fs_ioc_compress_file(struct file *filp)
 		goto out;
 	}
 
+	/* avoid race case between aio and ioc_compress_file */
+	inode_dio_wait(inode);
+
 	ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX);
 	if (ret)
 		goto out;
-- 
2.39.0