[PATCH v2] f2fs: change fiemap way in printing compression chunk

From: Daeho Jeong
Date: Thu Jul 22 2021 - 17:19:30 EST


From: Daeho Jeong <daehojeong@xxxxxxxxxx>

When we print out a discontinuous compression chunk, it shows like a
continuous chunk now. To show it more correctly, I've changed the way of
printing fiemap info like below. Plus, eliminated NEW_ADDR(-1) in fiemap
info, since it is not in fiemap user api manual.

Logical Physical Length Flags
0: 0000000000000000 0000000fdf692000 0000000000004000 1008
1: 0000000000004000 0000000fdf693000 0000000000004000 1008
2: 0000000000008000 0000000fdf694000 0000000000004000 1008
3: 000000000000c000 0000000fdf695000 0000000000004000 1008
4: 0000000000010000 0000000fdf696000 000000000000c000 1000
5: 000000000001c000 0000000f8c60d000 0000000000010000 1000
6: 000000000002c000 0000000f8c61d000 0000000000004000 1008
7: 0000000000030000 0000000f8c620000 0000000000004000 1008
8: 0000000000034000 0000000f8c623000 0000000000001000 1008
9: 0000000000035000 0000000fc7af4000 0000000000003000 1008

Flags
0x1000 => FIEMAP_EXTENT_MERGED
0x0008 => FIEMAP_EXTENT_ENCODED

Signed-off-by: Daeho Jeong <daehojeong@xxxxxxxxxx>

---
v2: changed the print format
---
fs/f2fs/data.c | 76 ++++++++++++++++++++++++++++----------------------
1 file changed, 42 insertions(+), 34 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 3a01a1b50104..058dc751e3a6 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1843,8 +1843,9 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 logical = 0, phys = 0, size = 0;
u32 flags = 0;
int ret = 0;
- bool compr_cluster = false;
+ bool compr_cluster = false, compr_appended;
unsigned int cluster_size = F2FS_I(inode)->i_cluster_size;
+ unsigned int count_in_cluster;
loff_t maxbytes;

if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
@@ -1892,8 +1893,10 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
map.m_next_pgofs = &next_pgofs;
map.m_seg_type = NO_CHECK_TYPE;

- if (compr_cluster)
- map.m_len = cluster_size - 1;
+ if (compr_cluster) {
+ map.m_lblk += 1;
+ map.m_len = cluster_size - count_in_cluster;
+ }

ret = f2fs_map_blocks(inode, &map, 0, F2FS_GET_BLOCK_FIEMAP);
if (ret)
@@ -1903,11 +1906,23 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
if (!(map.m_flags & F2FS_MAP_FLAGS)) {
start_blk = next_pgofs;

- if (blks_to_bytes(inode, start_blk) < blks_to_bytes(inode,
+ if (blks_to_bytes(inode, start_blk) >= blks_to_bytes(inode,
max_inode_blocks(inode)))
+ flags |= FIEMAP_EXTENT_LAST;
+ else if (!compr_cluster)
goto prep_next;
+ }
+
+ compr_appended = false;
+ /* In a case of compressed cluster, append this to the last extent */
+ if (compr_cluster && ((map.m_flags & F2FS_MAP_UNWRITTEN) ||
+ !(map.m_flags & F2FS_MAP_FLAGS))) {
+ unsigned int appended_blks = cluster_size - count_in_cluster + 1;

- flags |= FIEMAP_EXTENT_LAST;
+ size += blks_to_bytes(inode, appended_blks);
+ if (map.m_flags & F2FS_MAP_UNWRITTEN)
+ start_blk += appended_blks;
+ compr_appended = true;
}

if (size) {
@@ -1926,38 +1941,31 @@ int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
if (start_blk > last_blk)
goto out;

- if (compr_cluster) {
- compr_cluster = false;
-
-
- logical = blks_to_bytes(inode, start_blk - 1);
- phys = blks_to_bytes(inode, map.m_pblk);
- size = blks_to_bytes(inode, cluster_size);
-
- flags |= FIEMAP_EXTENT_ENCODED;
-
- start_blk += cluster_size - 1;
-
- if (start_blk > last_blk)
- goto out;
-
- goto prep_next;
- }
-
if (map.m_pblk == COMPRESS_ADDR) {
compr_cluster = true;
- start_blk++;
- goto prep_next;
- }
-
- logical = blks_to_bytes(inode, start_blk);
- phys = blks_to_bytes(inode, map.m_pblk);
- size = blks_to_bytes(inode, map.m_len);
- flags = 0;
- if (map.m_flags & F2FS_MAP_UNWRITTEN)
- flags = FIEMAP_EXTENT_UNWRITTEN;
+ count_in_cluster = 1;
+ } else if (compr_appended) {
+ compr_cluster = false;
+ } else {
+ logical = blks_to_bytes(inode, start_blk);
+ phys = __is_valid_data_blkaddr(map.m_pblk) ?
+ blks_to_bytes(inode, map.m_pblk) : 0;
+ size = blks_to_bytes(inode, map.m_len);
+ flags = 0;
+
+ if (compr_cluster) {
+ flags = FIEMAP_EXTENT_ENCODED;
+ count_in_cluster += map.m_len;
+ if (count_in_cluster == cluster_size) {
+ compr_cluster = false;
+ size += blks_to_bytes(inode, 1);
+ }
+ } else if (map.m_flags & F2FS_MAP_UNWRITTEN) {
+ flags = FIEMAP_EXTENT_UNWRITTEN;
+ }

- start_blk += bytes_to_blks(inode, size);
+ start_blk += bytes_to_blks(inode, size);
+ }

prep_next:
cond_resched();
--
2.32.0.432.gabb21c7263-goog