From: Davidlohr Bueso <dave@xxxxxxx>
The new lslocks(8) program is meant to replace the deprecated lslk(8). It is designed for simplicity
and removes unnecessary Unix legacy outputs and options:
- Don't output inode number, whence and maj:min device numbers.
- Don't provide nonblocking syscall options stat(2) and readlink(2)
- Remove lslk's alternate default kernel name list file path (-k)
The option to use nonblocking calls was previously intended for NFS partitions; however this should
be transparent to utility programs considering that timeouts can occur generically (fuse - sshfs, NFS, netdevs, etc).
Signed-off-by: Davidlohr Bueso <dave@xxxxxxx>
---
misc-utils/lslocks.c | 569 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 569 insertions(+), 0 deletions(-)
create mode 100644 misc-utils/lslocks.c
diff --git a/misc-utils/lslocks.c b/misc-utils/lslocks.c
new file mode 100644
index 0000000..2db72ef
--- /dev/null
+++ b/misc-utils/lslocks.c
@@ -0,0 +1,569 @@
+/*
+ * lslocks(8) - list local system locks
+ *
+ * Copyright (C) 2012 Davidlohr Bueso <dave@xxxxxxx>
+ *
+ * Very generally based on lslk(8) by Victor A. Abell <abe@xxxxxxxxxx>
+ * Since it stopped being maingained over a decade ago, this
+ * program should be considered its replacement.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <getopt.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "pathnames.h"
+#include "canonicalize.h"
+#include "nls.h"
+#include "tt.h"
+#include "xalloc.h"
+#include "strutils.h"
+#include "c.h"
+
+/* column IDs */
+enum {
+ COL_SRC = 0,
+ COL_PID,
+ COL_SIZE,
+ COL_ACCESS,
+ COL_M,
+ COL_START,
+ COL_END,
+ COL_PATH,
+};
+
+/* column names */
+struct colinfo {
+ const char *name; /* header */
+ double whint; /* width hint (N < 1 is in percent of termwidth) */
+ int flags; /* TT_FL_* */
+ const char *help;
+};
+
+/* columns descriptions */
+struct colinfo infos[] = {
+ [COL_SRC] = { "COMMAND", 0.30, TT_FL_TRUNC, N_("command of the process holding the lock") },
+ [COL_PID] = { "PID", 0.30, TT_FL_TRUNC, N_("PID of the process holding the lock") },
+ [COL_SIZE] = { "SIZE", 0.30, TT_FL_TRUNC, N_("size of the lock") },
+ [COL_ACCESS] = { "ACCESS", 0.30, TT_FL_TRUNC, N_("lock access type") },
+ [COL_M] = { "M", 0.30, TT_FL_TRUNC, N_("mandatory state of the lock: 0 (none), 1 (set)")},
+ [COL_START] = { "START", 0.30, TT_FL_TRUNC, N_("relative byte offset of the lock")},
+ [COL_END] = { "END", 0.30, TT_FL_TRUNC, N_("ending offset of the lock")},
+ [COL_PATH] = { "PATH", 0.30, TT_FL_TRUNC, N_("path of the locked file")},
+};
+#define NCOLS ARRAY_SIZE(infos)
+static int columns[NCOLS], ncolumns;
+static pid_t pid = 0;
+/* array with IDs of enabled columns */
+static int columns[NCOLS], ncolumns;
+
+struct lock {
+ struct list_head locks;
+
+ char *cmdname;
+ pid_t pid;
+ char *path;
+ char *type;
+ long start;
+ long end;
+ int mandatory;
+ char *size;
+};
+
+/*
+ * Return a PID's command name
+ */
+static char *get_cmdname(pid_t pid)
+{
+ FILE *fp;
+ char path[PATH_MAX], *cmd = NULL;
+
+ sprintf(path, "/proc/%d/status", pid);
+ if (!(fp = fopen(path, "r")))
+ return NULL;
+
+ /* just need the first line */
+ if (!fgets(path, sizeof(path), fp))
+ goto out;
+
+ (void)strtok_r(path, "\t", &cmd);
+ cmd[strlen(cmd) - 1] = '\0';
+out:
+ fclose(fp);
+ return xstrdup(cmd);
+}
+
+/*
+ * Associate the device's mountpoint for a filename
+ */
+static char *get_fallback_filename(size_t dev)
+{
+ char buf[PATH_MAX], *ret = NULL;
+ char *key = NULL, *tmp = NULL, *tok = NULL;
+ int i;
+ struct stat sb;
+ FILE *fp;
+
+ if (!(fp = fopen(_PATH_PROC_MOUNTS, "r")))
+ return NULL;
+
+ while (fgets(buf, sizeof(buf), fp)) {
+ for (i = 0, tmp = buf; ; tmp = NULL, i++) {
+ if (!(tok = strtok_r(tmp, " ", &key)))
+ break;
+
+ if (i == 1)
+ if (!stat(tok, &sb) && dev == sb.st_dev) {
+ ret = xstrdup(tok);
+ goto out;
+ }
+ }
+ }
+
+out:
+ fclose(fp);
+ return ret;
+}
+
+/*
+ * Return the absolute path of a file from
+ * a given inode number (and its size)
+ */
+static char *get_filename_sz(long inode, pid_t pid, size_t *size)
+{
+ struct stat sb;
+ struct dirent *dp;
+ DIR *dirp;
+ size_t len;
+ char path[PATH_MAX], sym[PATH_MAX], *ret = NULL;
+
+ *size = 0;
+ memset(path, 0, sizeof(path));
+ memset(sym, 0, sizeof(sym));
+
+ /*
+ * We know the pid so we don't have to
+ * iterate the *entire* filesystem searching
+ * for the damn file.
+ */
+ sprintf(path, "/proc/%d/fd/", pid);
+ if (!(dirp = opendir(path)))
+ return NULL;
+
+ if ((len = strlen(path)) >= (sizeof(path) - 2))
+ goto out;
+
+ while ((dp = readdir(dirp))) {
+ if (!strcmp(dp->d_name, ".") ||
+ !strcmp(dp->d_name, ".."))
+ continue;
+
+ /* care only for numerical descriptors */
+ if (!strtol(dp->d_name, (char **) NULL, 10))
+ continue;
+
+ (void) strcpy(&path[len], dp->d_name);
+ if (!stat(path, &sb) && inode != sb.st_ino)
+ continue;
+
+ if ((len = readlink(path, sym, sizeof(path))) < 1)
+ goto out;
+
+ *size = sb.st_size;
+ ret = xstrdup(sym);
+ break;
+ }
+out:
+ closedir(dirp);
+ return ret;
+}
+
+/*
+ * Return the inode number from a string
+ */
+static long get_dev_inode(char *str, dev_t *dev)
+{
+ char *tmp = NULL, *tok = NULL, *key = NULL;
+ int i, maj = 0, min = 0;
+ long inum = 0;
+
+ for (i = 0, tmp = str; ; tmp = NULL, i++) {
+ if (!(tok = strtok_r(tmp, ":", &key)))
+ break;
+
+ /*
+ * traditional format '<major>:<minor>:<inode>' - note that this
+ * might change and the kernel would export '<name>:<inode>'.
+ */
+ switch (i) {
+ case 0:
+ maj = strtol(tok, (char **) NULL, 16);
+ break;
+ case 1:
+ min = strtol(tok, (char **) NULL, 16);
+ break;
+ case 2:
+ inum = strtol_or_err(tok, _("failed to parse inode number"));
+ default:
+ break;
+ }
+ }
+
+ *dev = (dev_t) makedev(maj, min);
+ return inum;
+}
+
+static int get_local_locks(struct list_head *locks)
+{
+ int i;
+ long inode;
+ FILE *fp;
+ char buf[PATH_MAX], *key = NULL, *tmp = NULL, *tok = NULL;
+ size_t sz;
+ struct lock *l;
+ dev_t dev;
+ pid_t p;
+
+ if (!(fp = fopen(_PATH_PROC_LOCKS, "r")))
+ return 0;
+
+ while (fgets(buf, sizeof(buf), fp)) {
+ l = xcalloc(1, sizeof(*l));
+ INIT_LIST_HEAD(&l->locks);
+
+ for (i = 0, tmp = buf; ; tmp = NULL, i++) {
+ if (!(tok = strtok_r(tmp, " ", &key)))
+ break;
+
+ /*
+ * /proc/locks as *exactly* 8 "blocks" of text
+ * separated by ' ' - check <kernel>/fs/locks.c
+ */
+ switch (i) {
+ case 0: /* not intereted! */
+ case 1: /* not intereted! */
+ break;
+
+ case 2: /* is this a mandatory lock? other values are advisory or noinode */
+ l->mandatory = *tok == 'M' ? TRUE : FALSE;
+ break;
+ case 3: /* lock type */
+ l->type = xstrdup(tok);
+ break;
+
+ case 4: /* PID */
+ /*
+ * If user passed a pid we filter it later when adding
+ * to the list, no need to worry now.
+ */
+ l->pid = strtol_or_err(tok, _("failed to parse pid"));
+ l->cmdname = get_cmdname(l->pid);
+ break;
+
+ case 5: /* device major:minor and inode number */
+ inode = get_dev_inode(tok, &dev);
+ break;
+
+ case 6: /* start */
+ l->start = !strcmp(tok, "EOF") ? 0 :
+ strtol_or_err(tok, _("failed to parse start"));
+ break;
+
+ case 7: /* end */
+ /* replace '\n' character */
+ tok[strlen(tok)-1] = '\0';
+ l->end = !strcmp(tok, "EOF") ? 0 :
+ strtol_or_err(tok, _("failed to parse end"));
+ break;
+ default:
+ break;
+ }
+
+ l->path = get_filename_sz(inode, l->pid, &sz);
+ /* probably no permission to peek into l->pid's path */
+ if (!l->path)
+ l->path = get_fallback_filename(dev);
+
+ /* avoid leaking */
+ l->size = xstrdup(size_to_human_string(SIZE_SUFFIX_1LETTER, sz));
+ }
+
+ if (pid && pid != l->pid) {
+ /*
+ * It's easier to just parse the file then decide if
+ * it should be added to the list - otherwise just
+ * get rid of stored data
+ */
+ free(l->path);
+ free(l->size);
+ free(l->type);
+ free(l->cmdname);
+ free(l);
+
+ continue;
+ }
+
+ list_add(&l->locks, locks);
+ }
+
+ fclose(fp);
+ return 0;
+}
+
+static int column_name_to_id(const char *name, size_t namesz)
+{
+ size_t i;
+
+ assert(name);
+
+ for (i = 0; i < NCOLS; i++) {
+ const char *cn = infos[i].name;
+
+ if (!strncasecmp(name, cn, namesz) && !*(cn + namesz))
+ return i;
+ }
+ warnx(_("unknown column: %s"), name);
+ return -1;
+}
+
+static inline int get_column_id(int num)
+{
+ assert(ARRAY_SIZE(columns) == NCOLS);
+ assert(num < ncolumns);
+ assert(columns[num] < (int) NCOLS);
+
+ return columns[num];
+}
+
+
+static inline struct colinfo *get_column_info(unsigned num)
+{
+ return &infos[ get_column_id(num) ];
+}
+
+static void rem_lock(struct lock *lock)
+{
+ if (!lock)
+ return;
+
+ free(lock->path);
+ free(lock->size);
+ free(lock->type);
+ free(lock->cmdname);
+ list_del(&lock->locks);
+ free(lock);
+}
+
+static void add_tt_line(struct tt *tt, struct lock *l)
+{
+ int i;
+ struct tt_line *line;
+ /*
+ * Whenever cmdname or filename is NULL it is most
+ * likely because there's no read permissions
+ * for the specified process.
+ */
+ const char *notfnd = "";
+
+ assert(l);
+ assert(tt);
+
+ line = tt_add_line(tt, NULL);
+ if (!line) {
+ warn(_("failed to add line to output"));
+ return;
+ }
+
+ for (i = 0; i < ncolumns; i++) {
+ char *str = NULL;
+ int rc = 0;
+
+ switch (get_column_id(i)) {
+ case COL_SRC:
+ rc = asprintf(&str, "%s", l->cmdname ? l->cmdname : notfnd);
+ break;
+ case COL_PID:
+ rc = asprintf(&str, "%d", l->pid);
+ break;
+ case COL_SIZE:
+ rc = asprintf(&str, "%s", l->size);
+ break;
+ case COL_ACCESS:
+ rc = asprintf(&str, "%s", l->type);
+ break;
+ case COL_M:
+ rc = asprintf(&str, "%d", l->mandatory);
+ break;
+ case COL_START:
+ rc = asprintf(&str, "%ld", l->start);
+ break;
+ case COL_END:
+ rc = asprintf(&str, "%ld", l->end);
+ break;
+ case COL_PATH:
+ rc = asprintf(&str, "%s", l->path ? l->path : notfnd);
+ break;
+ default:
+ break;
+ }
+
+ if (rc || str)
+ tt_line_set_data(line, i, str);
+ }
+}
+
+static int show_locks(struct list_head *locks, int tt_flags)
+{
+ int i;
+ struct list_head *p, *pnext;
+ struct tt *tt;
+
+ tt = tt_new_table(tt_flags);
+ if (!tt) {
+ warn(_("failed to initialize output table"));
+ return -1;
+ }
+
+ for (i = 0; i < ncolumns; i++) {
+ struct colinfo *col = get_column_info(i);
+
+ if (!tt_define_column(tt, col->name, col->whint, col->flags)) {
+ warnx(_("failed to initialize output column"));
+ goto done;
+ }
+ }
+
+ list_for_each_safe(p, pnext, locks) {
+ struct lock *lock = list_entry(p, struct lock, locks);
+
+ add_tt_line(tt, lock);
+ rem_lock(lock);
+ }
+
+ tt_print_table(tt);
+done:
+ tt_free_table(tt);
+ return 0;
+}
+
+
+static void __attribute__ ((__noreturn__)) usage(FILE * out)
+{
+ size_t i;
+
+ fputs(USAGE_HEADER, out);
+
+ fprintf(out,
+ _(" %s [options]\n"), program_invocation_short_name);
+
+ fputs(_("\nGeneral Options:\n"), out);
+ fputs(_(" -p, --pid <pid> process id\n"
+ " -o, --output <list> define which output columns to use\n"
+ " --noheadings don't print headings\n"
+ " --raw use the raw output format\n"
+ " -h, --help display this help and exit\n"
+ " -V, --version output version information and exit\n"), out);
+
+ fputs(_("\nAvailable columns (for --output):\n"), out);
+
+ for (i = 0; i < NCOLS; i++)
+ fprintf(out, " %11s %s\n", infos[i].name, _(infos[i].help));
+
+ fprintf(out, USAGE_MAN_TAIL("lslocks(8)"));
+
+ exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
+}
+
+int main(int argc, char *argv[])
+{
+ int c, tt_flags = 0;
+ struct list_head locks;
+ enum {
+ RAW_OPTION = CHAR_MAX + 1,
+ NOHEADINGS_OPTION
+ };
+ static const struct option long_opts[] = {
+ { "pid", required_argument, NULL, 'p' },
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, 'V' },
+ { "noheadings", no_argument, NULL, NOHEADINGS_OPTION },
+ { "raw", no_argument, NULL, RAW_OPTION },
+ { NULL, 0, NULL, 0 }
+ };
+
+ setlocale(LC_ALL, "");
+ bindtextdomain(PACKAGE, LOCALEDIR);
+ textdomain(PACKAGE);
+
+ while ((c = getopt_long(argc, argv,
+ "p:o:hV", long_opts, NULL)) != -1) {
+
+ switch(c) {
+ case 'p':
+ pid = strtol_or_err(optarg, _("cannot parse PID"));
+ break;
+ case 'o':
+ ncolumns = string_to_idarray(optarg,
+ columns, ARRAY_SIZE(columns),
+ column_name_to_id);
+ if (ncolumns < 0)
+ return EXIT_FAILURE;
+ break;
+ case 'V':
+ printf(UTIL_LINUX_VERSION);
+ return EXIT_SUCCESS;
+ case 'h':
+ usage(stdout);
+ case NOHEADINGS_OPTION:
+ tt_flags |= TT_FL_NOHEADINGS;
+ break;
+ case RAW_OPTION:
+ tt_flags |= TT_FL_RAW;
+ break;
+ case '?':
+ default:
+ usage(stderr);
+ }
+ }
+
+ INIT_LIST_HEAD(&locks);
+
+ if (!ncolumns) {
+ /* default columns */
+ columns[ncolumns++] = COL_SRC;
+ columns[ncolumns++] = COL_PID;
+ columns[ncolumns++] = COL_SIZE;
+ columns[ncolumns++] = COL_ACCESS;
+ columns[ncolumns++] = COL_M;
+ columns[ncolumns++] = COL_START;
+ columns[ncolumns++] = COL_END;
+ columns[ncolumns++] = COL_PATH;
+ }
+
+ get_local_locks(&locks);
+
+ if (!list_empty(&locks))
+ show_locks(&locks, tt_flags);
+
+ return EXIT_SUCCESS;
+}
--
1.7.4.1
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