f2fs: add missing description for ipu_policy node

IPU policy can be disabled, let's add description for it and other policy.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs
index 0f17adc..9413274 100644 (file)
--- a/Documentation/ABI/testing/sysfs-fs-f2fs
+++ b/Documentation/ABI/testing/sysfs-fs-f2fs
@@ -49,16 +49,23 @@ Contact:    "Jaegeuk Kim" <jaegeuk.kim@samsung.com>
 Description:   Controls the in-place-update policy.
                updates in f2fs. User can set:
 
-               ====  =================
-               0x01  F2FS_IPU_FORCE
-               0x02  F2FS_IPU_SSR
-               0x04  F2FS_IPU_UTIL
-               0x08  F2FS_IPU_SSR_UTIL
-               0x10  F2FS_IPU_FSYNC
-               0x20  F2FS_IPU_ASYNC
-               0x40  F2FS_IPU_NOCACHE
-               0x80  F2FS_IPU_HONOR_OPU_WRITE
-               ====  =================
+               ===== =============== ===================================================
+               value policy          description
+               0x00  DISABLE         disable IPU(=default option in LFS mode)
+               0x01  FORCE           all the time
+               0x02  SSR             if SSR mode is activated
+               0x04  UTIL            if FS utilization is over threashold
+               0x08  SSR_UTIL        if SSR mode is activated and FS utilization is over
+                                     threashold
+               0x10  FSYNC           activated in fsync path only for high performance
+                                     flash storages. IPU will be triggered only if the
+                                     # of dirty pages over min_fsync_blocks.
+                                     (=default option)
+               0x20  ASYNC           do IPU given by asynchronous write requests
+               0x40  NOCACHE         disable IPU bio cache
+               0x80  HONOR_OPU_WRITE use OPU write prior to IPU write if inode has
+                                     FI_OPU_WRITE flag
+               ===== =============== ===================================================
 
                Refer segment.h for details.