nilfs2: support contiguous lookup of blocks
Although get_block() callback function can return extent of contiguous
blocks with bh->b_size, nilfs_get_block() function did not support
this feature.
This adds contiguous lookup feature to the block mapping codes of
nilfs, and allows the nilfs_get_blocks() function to return the extent
information by applying the feature.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/direct.c b/fs/nilfs2/direct.c
index 33467ad..342d976 100644
--- a/fs/nilfs2/direct.c
+++ b/fs/nilfs2/direct.c
@@ -25,6 +25,7 @@
#include "page.h"
#include "direct.h"
#include "alloc.h"
+#include "dat.h"
static inline __le64 *nilfs_direct_dptrs(const struct nilfs_direct *direct)
{
@@ -62,6 +63,47 @@
return 0;
}
+static int nilfs_direct_lookup_contig(const struct nilfs_bmap *bmap,
+ __u64 key, __u64 *ptrp,
+ unsigned maxblocks)
+{
+ struct nilfs_direct *direct = (struct nilfs_direct *)bmap;
+ struct inode *dat = NULL;
+ __u64 ptr, ptr2;
+ sector_t blocknr;
+ int ret, cnt;
+
+ if (key > NILFS_DIRECT_KEY_MAX ||
+ (ptr = nilfs_direct_get_ptr(direct, key)) ==
+ NILFS_BMAP_INVALID_PTR)
+ return -ENOENT;
+
+ if (NILFS_BMAP_USE_VBN(bmap)) {
+ dat = nilfs_bmap_get_dat(bmap);
+ ret = nilfs_dat_translate(dat, ptr, &blocknr);
+ if (ret < 0)
+ return ret;
+ ptr = blocknr;
+ }
+
+ maxblocks = min_t(unsigned, maxblocks, NILFS_DIRECT_KEY_MAX - key + 1);
+ for (cnt = 1; cnt < maxblocks &&
+ (ptr2 = nilfs_direct_get_ptr(direct, key + cnt)) !=
+ NILFS_BMAP_INVALID_PTR;
+ cnt++) {
+ if (dat) {
+ ret = nilfs_dat_translate(dat, ptr2, &blocknr);
+ if (ret < 0)
+ return ret;
+ ptr2 = blocknr;
+ }
+ if (ptr2 != ptr + cnt)
+ break;
+ }
+ *ptrp = ptr;
+ return cnt;
+}
+
static __u64
nilfs_direct_find_target_v(const struct nilfs_direct *direct, __u64 key)
{
@@ -367,6 +409,7 @@
static const struct nilfs_bmap_operations nilfs_direct_ops = {
.bop_lookup = nilfs_direct_lookup,
+ .bop_lookup_contig = nilfs_direct_lookup_contig,
.bop_insert = nilfs_direct_insert,
.bop_delete = nilfs_direct_delete,
.bop_clear = NULL,
