[PATCH 02/18] f2fs: report unwritten area in f2fs_fiemap

Jaegeuk Kim
2015-05-09T04:26:40Z

This patch slightly changes f2fs_fiemap function to report unwritten area.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
fs/f2fs/data.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++++++--
fs/f2fs/f2fs.h | 4 +-
2 files changed, 117 insertions(+), 4 deletions(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 3b76261..842fcdd 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1241,6 +1241,8 @@ static int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
if (dn.data_blkaddr != NULL_ADDR) {
map->m_flags = F2FS_MAP_MAPPED;
map->m_pblk = dn.data_blkaddr;
+ if (dn.data_blkaddr == NEW_ADDR)
+ map->m_flags |= F2FS_MAP_UNWRITTEN;
} else if (create) {
err = __allocate_data_block(&dn);
if (err)
@@ -1288,7 +1290,10 @@ get_next:
blkaddr = dn.data_blkaddr;
}
/* Give more consecutive addresses for the readahead */
- if (map->m_pblk != NEW_ADDR && blkaddr == (map->m_pblk + ofs)) {
+ if ((map->m_pblk != NEW_ADDR &&
+ blkaddr == (map->m_pblk + ofs)) ||
+ (map->m_pblk == NEW_ADDR &&
+ blkaddr == NEW_ADDR)) {
ofs++;
dn.ofs_in_node++;
pgofs++;
@@ -1339,11 +1344,117 @@ static int get_data_block_fiemap(struct inode *inode, sector_t iblock,
return __get_data_block(inode, iblock, bh_result, create, true);
}

+static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
+{
+ return (offset >> inode->i_blkbits);
+}
+
+static inline loff_t blk_to_logical(struct inode *inode, sector_t blk)
+{
+ return (blk << inode->i_blkbits);
+}
+
int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len)
{
- return generic_block_fiemap(inode, fieinfo,
- start, len, get_data_block_fiemap);
+ struct buffer_head map_bh;
+ sector_t start_blk, last_blk;
+ loff_t isize = i_size_read(inode);
+ u64 logical = 0, phys = 0, size = 0;
+ u32 flags = 0;
+ bool past_eof = false, whole_file = false;
+ int ret = 0;
+
+ ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
+ if (ret)
+ return ret;
+
+ mutex_lock(&inode->i_mutex);
+
+ if (len >= isize) {
+ whole_file = true;
+ len = isize;
+ }
+
+ if (logical_to_blk(inode, len) == 0)
+ len = blk_to_logical(inode, 1);
+
+ start_blk = logical_to_blk(inode, start);
+ last_blk = logical_to_blk(inode, start + len - 1);
+next:
+ memset(&map_bh, 0, sizeof(struct buffer_head));
+ map_bh.b_size = len;
+
+ ret = get_data_block_fiemap(inode, start_blk, &map_bh, 0);
+ if (ret)
+ goto out;
+
+ /* HOLE */
+ if (!buffer_mapped(&map_bh)) {
+ start_blk++;
+
+ if (!past_eof && blk_to_logical(inode, start_blk) >= isize)
+ past_eof = 1;
+
+ if (past_eof && size) {
+ flags |= FIEMAP_EXTENT_LAST;
+ ret = fiemap_fill_next_extent(fieinfo, logical,
+ phys, size, flags);
+ } else if (size) {
+ ret = fiemap_fill_next_extent(fieinfo, logical,
+ phys, size, flags);
+ size = 0;
+ }
+
+ /* if we have holes up to/past EOF then we're done */
+ if (start_blk > last_blk || past_eof || ret)
+ goto out;
+ } else {
+ if (start_blk > last_blk && !whole_file) {
+ ret = fiemap_fill_next_extent(fieinfo, logical,
+ phys, size, flags);
+ goto out;
+ }
+
+ /*
+ * if size != 0 then we know we already have an extent
+ * to add, so add it.
+ */
+ if (size) {
+ ret = fiemap_fill_next_extent(fieinfo, logical,
+ phys, size, flags);
+ if (ret)
+ goto out;
+ }
+
+ logical = blk_to_logical(inode, start_blk);
+ phys = blk_to_logical(inode, map_bh.b_blocknr);
+ size = map_bh.b_size;
+ flags = 0;
+ if (buffer_unwritten(&map_bh))
+ flags = FIEMAP_EXTENT_UNWRITTEN;
+
+ start_blk += logical_to_blk(inode, size);
+
+ /*
+ * If we are past the EOF, then we need to make sure as
+ * soon as we find a hole that the last extent we found
+ * is marked with FIEMAP_EXTENT_LAST
+ */
+ if (!past_eof && logical + size >= isize)
+ past_eof = true;
+ }
+ cond_resched();
+ if (fatal_signal_pending(current))
+ ret = -EINTR;
+ else
+ goto next;
+out:
+ if (ret == 1)
+ ret = 0;
+
+ mutex_unlock(&inode->i_mutex);
+ return ret;
}

/*
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 160945f..477e65f 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -330,7 +330,9 @@ struct extent_tree {
*/
#define F2FS_MAP_NEW (1 << BH_New)
#define F2FS_MAP_MAPPED (1 << BH_Mapped)
-#define F2FS_MAP_FLAGS (F2FS_MAP_NEW | F2FS_MAP_MAPPED)
+#define F2FS_MAP_UNWRITTEN (1 << BH_Unwritten)
+#define F2FS_MAP_FLAGS (F2FS_MAP_NEW | F2FS_MAP_MAPPED |\
+ F2FS_MAP_UNWRITTEN)

struct f2fs_map_blocks {
block_t m_pblk;
--
2.1.1