[PATCH] lssu: display a "p" flag on protected segments

[Ryusuke Konishi]

Display a "p" flag in STAT field of the output lines of protected
segments when -l (--latest-usage) option is specfied. This flag
clarifies which segments are protected by garbage collection at that
moment.

Signed-off-by: Ryusuke Konishi <konishi.ryusuke-***@public.gmane.org>
---
bin/lssu.c | 29 ++++++++++++++++++-----------
man/lssu.1 | 17 +++++++++++++----
2 files changed, 31 insertions(+), 15 deletions(-)

diff --git a/bin/lssu.c b/bin/lssu.c
index 1873957..bef4749 100644
--- a/bin/lssu.c
+++ b/bin/lssu.c
@@ -104,7 +104,7 @@ const static struct lssu_format lssu_format[] = {
{
" SEGNUM DATE TIME STAT NBLOCKS"
" NLIVEBLOCKS\n",
- "%17llu %s %c%c%c %10u %10u (%3u%%)\n"
+ "%17llu %s %c%c%c%c %10u %10u (%3u%%)\n"
}
};

@@ -114,6 +114,7 @@ static int all;
static int latest;
static int disp_mode; /* display mode */
static nilfs_cno_t protcno;
+static __u64 prottime;
static __u64 param_index;
static __u64 param_lines;

@@ -163,6 +164,7 @@ static ssize_t lssu_print_suinfo(struct nilfs *nilfs, __u64 segnum,
char timebuf[LSSU_BUFSIZE];
ssize_t i, n = 0, ret;
int ratio;
+ int protected;
size_t nliveblks;

for (i = 0; i < nsi; i++, segnum++) {
@@ -190,6 +192,7 @@ static ssize_t lssu_print_suinfo(struct nilfs *nilfs, __u64 segnum,
case LSSU_MODE_LATEST_USAGE:
nliveblks = 0;
ratio = 0;
+ protected = suinfos[i].sui_lastmod >= prottime;

if (!nilfs_suinfo_dirty(&suinfos[i]) ||
nilfs_suinfo_error(&suinfos[i]))
@@ -203,6 +206,7 @@ static ssize_t lssu_print_suinfo(struct nilfs *nilfs, __u64 segnum,
} else if (ret == -2) {
nliveblks = suinfos[i].sui_nblocks;
ratio = 100;
+ protected = 1;
} else {
fprintf(stderr,
"%s: failed to get usage: %s\n",
@@ -217,6 +221,7 @@ static ssize_t lssu_print_suinfo(struct nilfs *nilfs, __u64 segnum,
nilfs_suinfo_active(&suinfos[i]) ? 'a' : '-',
nilfs_suinfo_dirty(&suinfos[i]) ? 'd' : '-',
nilfs_suinfo_error(&suinfos[i]) ? 'e' : '-',
+ protected ? 'p' : '-',
suinfos[i].sui_nblocks, nliveblks, ratio);
break;
}
@@ -253,24 +258,25 @@ static int lssu_list_suinfo(struct nilfs *nilfs)

static int lssu_get_protcno(struct nilfs *nilfs,
unsigned long protection_period,
- nilfs_cno_t *protcnop)
+ __u64 *prottimep, nilfs_cno_t *protcnop)
{
struct nilfs_cnoconv *cnoconv;
struct timeval tv;
- __u64 prottime;
int ret;

- if (protection_period == ULONG_MAX) {
- *protcnop = NILFS_CNO_MAX;
- return 0;
- }
-
ret = gettimeofday(&tv, NULL);
if (ret < 0) {
fprintf(stderr, "%s: cannot get current time: %m\n", progname);
return -1;
}
- prottime = tv.tv_sec - protection_period;
+
+ if (protection_period == ULONG_MAX) {
+ *protcnop = NILFS_CNO_MAX;
+ *prottimep = tv.tv_sec;
+ return 0;
+ }
+
+ *prottimep = tv.tv_sec - protection_period;

cnoconv = nilfs_cnoconv_create(nilfs);
if (!cnoconv) {
@@ -280,7 +286,7 @@ static int lssu_get_protcno(struct nilfs *nilfs,
return -1;
}

- ret = nilfs_cnoconv_time2cno(cnoconv, prottime, protcnop);
+ ret = nilfs_cnoconv_time2cno(cnoconv, *prottimep, protcnop);
if (ret < 0) {
fprintf(stderr,
"%s: cannot convert protectoin time to checkpoint "
@@ -383,7 +389,8 @@ int main(int argc, char *argv[])
if (latest) {
blocks_per_segment = nilfs_get_blocks_per_segment(nilfs);
disp_mode = LSSU_MODE_LATEST_USAGE;
- ret = lssu_get_protcno(nilfs, protection_period, &protcno);
+ ret = lssu_get_protcno(nilfs, protection_period, &prottime,
+ &protcno);
if (ret < 0)
exit(1);
}
diff --git a/man/lssu.1 b/man/lssu.1
index 2b58f8f..0607b84 100644
--- a/man/lssu.1
+++ b/man/lssu.1
@@ -35,8 +35,11 @@ List only \fIlines\fP input segments.
.TP
\fB\-p \fIperiod\fR, \fB\-\-protection-period\fR=\fIperiod\fR
Specify protection period. This option is used when printing usage
-status of the moment (with \fB\-l\fR option) to test if each
-block in segments is protected and is not reclaimable.
+status of the moment (with \fB\-l\fR option) to test if each block in
+segments is protected and is not reclaimable. Optionally, the
+\fIperiod\fP parameter may be suffixed by one of the following units
+designators: \'s\', \'m\', \'h\', \'d\',\'w\',\'M\', or \'Y\', for
+seconds, minutes, hours, days, weeks, months, or years, respectively.
.TP
\fB\-V\fR, \fB\-\-version\fR
Display version and exit.
@@ -53,8 +56,7 @@ Creation date.
Creation time.
.TP
.B STAT
-State of the segment. It consists of three flags whose meaning is
-shown below:
+State of the segment. It consists of the following flags:
.RS
.TP
.B a
@@ -67,6 +69,13 @@ The segment is dirty, meaning that it is in use.
.B e
The segment is erroneous, meaning that it has once caused an I/O
error. NILFS2 avoids allocating the segments with this flag.
+.TP
+.B p (optional)
+The segment is protected, meaning that garbage collection for the
+segment is prevented for some reason, for instance, the protection
+period is not elapsed from its last modified time, the segment is
+pinned by a super block, or it is erroneous and unreclaimable, etc.
+This flag is displayed when \fB\-l\fR option is specified.
.RE
.TP
.B NBLOCKS