This patch adds support for the field su_nsnapshot_blks and includes the
necessary flags to update it from the GC.
The GC already has the necessary information about which block belongs
to a snapshot and which doesn't. So these blocks are counted up and
passed to the caller.
The number of snapshot blocks will then be updated with
NILFS_IOCTL_SET_SUINFO ioctl.
Signed-off-by: Andreas Rohner <andreas.rohner@xxxxxxx>
---
include/nilfs.h | 9 +++++++++
include/nilfs2_fs.h | 12 ++++++++----
lib/feature.c | 2 ++
lib/gc.c | 19 ++++++++++++++-----
lib/nilfs.c | 2 ++
man/mkfs.nilfs2.8 | 6 ++++++
sbin/mkfs/mkfs.c | 3 ++-
sbin/nilfs-tune/nilfs-tune.c | 6 ++++--
8 files changed, 47 insertions(+), 12 deletions(-)
diff --git a/include/nilfs.h b/include/nilfs.h
index 8511163..e84656b 100644
--- a/include/nilfs.h
+++ b/include/nilfs.h
@@ -131,6 +131,7 @@ struct nilfs {
#define NILFS_OPT_MMAP 0x01
#define NILFS_OPT_SET_SUINFO 0x02
#define NILFS_OPT_TRACK_LIVE_BLKS 0x04
+#define NILFS_OPT_TRACK_SNAPSHOTS 0x08
struct nilfs *nilfs_open(const char *, const char *, int);
@@ -161,6 +162,7 @@ nilfs_opt_test_##name(const struct nilfs *nilfs) \
NILFS_OPT_FLAG(SET_SUINFO, set_suinfo);
NILFS_OPT_FLAG(TRACK_LIVE_BLKS, track_live_blks);
+NILFS_OPT_FLAG(TRACK_SNAPSHOTS, track_snapshots);
nilfs_cno_t nilfs_get_oldest_cno(struct nilfs *);
@@ -356,4 +358,11 @@ static inline int nilfs_feature_track_live_blks(const struct nilfs *nilfs)
(fc & NILFS_FEATURE_COMPAT_SUFILE_EXTENSION);
}
+static inline int nilfs_feature_track_snapshots(const struct nilfs *nilfs)
+{
+ __u64 fc = le64_to_cpu(nilfs->n_sb->s_feature_compat);
+ return (fc & NILFS_FEATURE_COMPAT_TRACK_SNAPSHOTS) &&
+ nilfs_feature_track_live_blks(nilfs);
+}
+
#endif /* NILFS_H */
diff --git a/include/nilfs2_fs.h b/include/nilfs2_fs.h
index 427ca53..f1f315c 100644
--- a/include/nilfs2_fs.h
+++ b/include/nilfs2_fs.h
@@ -221,11 +221,13 @@ struct nilfs_super_block {
*/
#define NILFS_FEATURE_COMPAT_SUFILE_EXTENSION (1ULL << 0)
#define NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS (1ULL << 1)
+#define NILFS_FEATURE_COMPAT_TRACK_SNAPSHOTS (1ULL << 2)
#define NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT (1ULL << 0)
#define NILFS_FEATURE_COMPAT_SUPP (NILFS_FEATURE_COMPAT_SUFILE_EXTENSION \
- | NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS)
+ | NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS \
+ | NILFS_FEATURE_COMPAT_TRACK_SNAPSHOTS)
#define NILFS_FEATURE_COMPAT_RO_SUPP NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT
#define NILFS_FEATURE_INCOMPAT_SUPP 0ULL
@@ -630,7 +632,7 @@ struct nilfs_segment_usage {
__le32 su_nblocks;
__le32 su_flags;
__le32 su_nlive_blks;
- __le32 su_pad;
+ __le32 su_nsnapshot_blks;
__le64 su_nlive_lastmod;
};
@@ -682,7 +684,7 @@ nilfs_segment_usage_set_clean(struct nilfs_segment_usage *su, size_t susz)
su->su_flags = cpu_to_le32(0);
if (susz >= NILFS_EXT_SEGMENT_USAGE_SIZE) {
su->su_nlive_blks = cpu_to_le32(0);
- su->su_pad = cpu_to_le32(0);
+ su->su_nsnapshot_blks = cpu_to_le32(0);
su->su_nlive_lastmod = cpu_to_le64(0);
}
}
@@ -723,7 +725,7 @@ struct nilfs_suinfo {
__u32 sui_nblocks;
__u32 sui_flags;
__u32 sui_nlive_blks;
- __u32 sui_pad;
+ __u32 sui_nsnapshot_blks;
__u64 sui_nlive_lastmod;
};
@@ -764,6 +766,7 @@ enum {
NILFS_SUINFO_UPDATE_FLAGS,
NILFS_SUINFO_UPDATE_NLIVE_BLKS,
NILFS_SUINFO_UPDATE_NLIVE_LASTMOD,
+ NILFS_SUINFO_UPDATE_NSNAPSHOT_BLKS,
__NR_NILFS_SUINFO_UPDATE_FIELDS,
};
@@ -788,6 +791,7 @@ NILFS_SUINFO_UPDATE_FNS(LASTMOD, lastmod)
NILFS_SUINFO_UPDATE_FNS(NBLOCKS, nblocks)
NILFS_SUINFO_UPDATE_FNS(FLAGS, flags)
NILFS_SUINFO_UPDATE_FNS(NLIVE_BLKS, nlive_blks)
+NILFS_SUINFO_UPDATE_FNS(NSNAPSHOT_BLKS, nsnapshot_blks)
NILFS_SUINFO_UPDATE_FNS(NLIVE_LASTMOD, nlive_lastmod)
enum {
diff --git a/lib/feature.c b/lib/feature.c
index ebe8c3f..376fa53 100644
--- a/lib/feature.c
+++ b/lib/feature.c
@@ -59,6 +59,8 @@ static const struct nilfs_feature features[] = {
NILFS_FEATURE_COMPAT_SUFILE_EXTENSION, "sufile_ext" },
{ NILFS_FEATURE_TYPE_COMPAT,
NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS, "track_live_blks" },
+ { NILFS_FEATURE_TYPE_COMPAT,
+ NILFS_FEATURE_COMPAT_TRACK_SNAPSHOTS, "track_snapshots" },
/* Read-only compat features */
{ NILFS_FEATURE_TYPE_COMPAT_RO,
NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT, "block_count" },
diff --git a/lib/gc.c b/lib/gc.c
index a2461b9..f1b8b85 100644
--- a/lib/gc.c
+++ b/lib/gc.c
@@ -629,12 +629,13 @@ static int nilfs_toss_bdescs(struct nilfs_vector *bdescv)
static size_t nilfs_count_nlive_blks(const struct nilfs *nilfs,
__u64 segnum,
struct nilfs_vector *vdescv,
- struct nilfs_vector *bdescv)
+ struct nilfs_vector *bdescv,
+ size_t *pnss)
{
struct nilfs_vdesc *vdesc;
struct nilfs_bdesc *bdesc;
int i;
- size_t res = 0;
+ size_t res = 0, nss = 0;
for (i = 0; i < nilfs_vector_get_size(bdescv); i++) {
bdesc = nilfs_vector_get_element(bdescv, i);
@@ -651,10 +652,16 @@ static size_t nilfs_count_nlive_blks(const struct nilfs *nilfs,
if (nilfs_get_segnum_of_block(nilfs, vdesc->vd_blocknr) ==
segnum && (nilfs_vdesc_snapshot(vdesc) ||
- !nilfs_vdesc_protection_period(vdesc)))
+ !nilfs_vdesc_protection_period(vdesc))) {
++res;
+ if (nilfs_vdesc_snapshot(vdesc))
+ ++nss;
+ }
}
+ if (pnss)
+ *pnss = nss;
+
return res;
}
@@ -685,7 +692,7 @@ static int nilfs_try_set_suinfo(struct nilfs *nilfs, __u64 *segnums,
struct nilfs_suinfo_update *sup;
struct timeval tv;
int ret = -1;
- size_t i, nblocks;
+ size_t i, nblocks, nss;
supv = nilfs_vector_create(sizeof(struct nilfs_suinfo_update));
if (!supv)
@@ -709,10 +716,12 @@ static int nilfs_try_set_suinfo(struct nilfs *nilfs, __u64 *segnums,
if (nilfs_opt_test_track_live_blks(nilfs)) {
nilfs_suinfo_update_set_nlive_blks(sup);
+ nilfs_suinfo_update_set_nsnapshot_blks(sup);
nblocks = nilfs_count_nlive_blks(nilfs,
- segnums[i], vdescv, bdescv);
+ segnums[i], vdescv, bdescv, &nss);
sup->sup_sui.sui_nlive_blks = nblocks;
+ sup->sup_sui.sui_nsnapshot_blks = nss;
}
}
diff --git a/lib/nilfs.c b/lib/nilfs.c
index 2067fc0..c453d5b 100644
--- a/lib/nilfs.c
+++ b/lib/nilfs.c
@@ -381,6 +381,8 @@ struct nilfs *nilfs_open(const char *dev, const char *dir, int flags)
if (nilfs_feature_track_live_blks(nilfs))
nilfs_opt_set_track_live_blks(nilfs);
+ if (nilfs_feature_track_snapshots(nilfs))
+ nilfs_opt_set_track_snapshots(nilfs);
}
if (flags &
diff --git a/man/mkfs.nilfs2.8 b/man/mkfs.nilfs2.8
index 2431ac9..c784883 100644
--- a/man/mkfs.nilfs2.8
+++ b/man/mkfs.nilfs2.8
@@ -182,6 +182,12 @@ Enables the tracking of live blocks, which might improve the effectiveness of
garbage collection, but entails a small runtime overhead. It is important to
note, that this feature depends on sufile_ext, which can only be set
at file system creation time.
+.TP
+.B track_snapshots
+Enables an efficient heuristic tracking of the number of snapshot blocks in a
+segment. This prevents starvation of segments and improves the overall
+performance. It is important to note, that this feature depends on sufile_ext,
+which can only be set at file system creation time.
.RE
.TP
.B \-q
diff --git a/sbin/mkfs/mkfs.c b/sbin/mkfs/mkfs.c
index 680311c..e69abc8 100644
--- a/sbin/mkfs/mkfs.c
+++ b/sbin/mkfs/mkfs.c
@@ -1083,7 +1083,8 @@ static inline void check_ctime(time_t ctime)
static const __u64 ok_features[NILFS_MAX_FEATURE_TYPES] = {
/* Compat */
NILFS_FEATURE_COMPAT_SUFILE_EXTENSION |
- NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS,
+ NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS |
+ NILFS_FEATURE_COMPAT_TRACK_SNAPSHOTS,
/* Read-only compat */
NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT,
/* Incompat */
diff --git a/sbin/nilfs-tune/nilfs-tune.c b/sbin/nilfs-tune/nilfs-tune.c
index 7889310..d595366 100644
--- a/sbin/nilfs-tune/nilfs-tune.c
+++ b/sbin/nilfs-tune/nilfs-tune.c
@@ -84,7 +84,8 @@ static void nilfs_tune_usage(void)
static const __u64 ok_features[NILFS_MAX_FEATURE_TYPES] = {
/* Compat */
- NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS,
+ NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS |
+ NILFS_FEATURE_COMPAT_TRACK_SNAPSHOTS,
/* Read-only compat */
NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT,
/* Incompat */
@@ -93,7 +94,8 @@ static const __u64 ok_features[NILFS_MAX_FEATURE_TYPES] = {
static const __u64 clear_ok_features[NILFS_MAX_FEATURE_TYPES] = {
/* Compat */
- NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS,
+ NILFS_FEATURE_COMPAT_TRACK_LIVE_BLKS |
+ NILFS_FEATURE_COMPAT_TRACK_SNAPSHOTS,
/* Read-only compat */
NILFS_FEATURE_COMPAT_RO_BLOCK_COUNT,
/* Incompat */
--
2.3.0
--
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