The underlay block storage could work in a stripe-like manner to improve
performance and space efficiency.
EROFS on-disk layout is flexible enough for such use cases.
Cc: Changpeng Liu <changpe...@tencent.com>
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
include/erofs/cache.h | 3 +++
lib/cache.c | 2 ++
man/mkfs.erofs.1 | 3 +++
mkfs/main.c | 11 +++++++++++
4 files changed, 19 insertions(+)
diff --git a/include/erofs/cache.h b/include/erofs/cache.h
index 5411eed..bd32602 100644
--- a/include/erofs/cache.h
+++ b/include/erofs/cache.h
@@ -64,6 +64,9 @@ struct erofs_bufmgr {
/* last mapped buffer block to accelerate erofs_mapbh() */
struct erofs_buffer_block *last_mapped_block;
+
+ /* align data block addresses to multiples of `dsunit` */
+ unsigned int dsunit;
};
static inline const int get_alignsize(struct erofs_sb_info *sbi, int type,
diff --git a/lib/cache.c b/lib/cache.c
index 3208e9f..b782f25 100644
--- a/lib/cache.c
+++ b/lib/cache.c
@@ -330,6 +330,8 @@ static erofs_blk_t __erofs_mapbh(struct erofs_buffer_block
*bb)
if (bb->blkaddr == NULL_ADDR) {
bb->blkaddr = bmgr->tail_blkaddr;
+ if (__erofs_unlikely(bmgr->dsunit) && bb->type == DATA)
+ bb->blkaddr = roundup(bb->blkaddr, bmgr->dsunit);
bmgr->last_mapped_block = bb;
erofs_bupdate_mapped(bb);
}
diff --git a/man/mkfs.erofs.1 b/man/mkfs.erofs.1
index abdd9b9..e7da588 100644
--- a/man/mkfs.erofs.1
+++ b/man/mkfs.erofs.1
@@ -138,6 +138,9 @@ the given primary algorithm, alternative algorithms can be
specified with
are extended regular expressions, matched against absolute paths within
the output filesystem, with no leading /.
.TP
+.BI "\-\-dsunit=" #
+Align all data block addresses to multiples of #.
+.TP
.BI "\-\-exclude-path=" path
Ignore file that matches the exact literal path.
You may give multiple
diff --git a/mkfs/main.c b/mkfs/main.c
index d422787..c92f408 100644
--- a/mkfs/main.c
+++ b/mkfs/main.c
@@ -85,6 +85,7 @@ static struct option long_options[] = {
{"mkfs-time", no_argument, NULL, 525},
{"all-time", no_argument, NULL, 526},
{"sort", required_argument, NULL, 527},
+ {"dsunit", required_argument, NULL, 528},
{0, 0, 0, 0},
};
@@ -161,6 +162,7 @@ static void usage(int argc, char **argv)
" --blobdev=X specify an extra device X to store
chunked data\n"
" --chunksize=# generate chunk-based files with #-byte
chunks\n"
" --clean=X run full clean build (default) or:\n"
+ " --dsunit=# align all data block addresses to
multiples of #\n"
" --incremental=X run incremental build\n"
" (X = data|rvsp; data=full data,
rvsp=space is allocated\n"
" and filled with
zeroes)\n"
@@ -241,6 +243,7 @@ static unsigned int rebuild_src_count;
static LIST_HEAD(rebuild_src_list);
static u8 fixeduuid[16];
static bool valid_fixeduuid;
+static unsigned int dsunit;
static int erofs_mkfs_feat_set_legacy_compress(bool en, const char *val,
unsigned int vallen)
@@ -846,6 +849,13 @@ static int mkfs_parse_options_cfg(int argc, char *argv[])
if (!strcmp(optarg, "none"))
erofstar.try_no_reorder = true;
break;
+ case 528:
+ dsunit = strtoul(optarg, &endptr, 0);
+ if (*endptr != '\0') {
+ erofs_err("invalid dsunit %s", optarg);
+ return -EINVAL;
+ }
+ break;
case 'V':
version();
exit(0);
@@ -1308,6 +1318,7 @@ int main(int argc, char **argv)
}
sb_bh = NULL;
}
+ g_sbi.bmgr->dsunit = dsunit;
/* Use the user-defined UUID or generate one for clean builds */
if (valid_fixeduuid)
--
2.43.5
