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Diffstat (limited to 'sys/contrib/openzfs/lib/libzfs/libzfs_diff.c')
-rw-r--r--sys/contrib/openzfs/lib/libzfs/libzfs_diff.c830
1 files changed, 830 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/lib/libzfs/libzfs_diff.c b/sys/contrib/openzfs/lib/libzfs/libzfs_diff.c
new file mode 100644
index 000000000000..5f50bce531f7
--- /dev/null
+++ b/sys/contrib/openzfs/lib/libzfs/libzfs_diff.c
@@ -0,0 +1,830 @@
+// SPDX-License-Identifier: CDDL-1.0
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or https://opensource.org/licenses/CDDL-1.0.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright 2015 Nexenta Systems, Inc. All rights reserved.
+ * Copyright (c) 2015, 2018 by Delphix. All rights reserved.
+ * Copyright 2016 Joyent, Inc.
+ * Copyright 2016 Igor Kozhukhov <ikozhukhov@gmail.com>
+ */
+
+/*
+ * zfs diff support
+ */
+#include <ctype.h>
+#include <errno.h>
+#include <libintl.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <sys/zfs_ioctl.h>
+#include <libzfs.h>
+#include <libzutil.h>
+#include "libzfs_impl.h"
+
+#define ZDIFF_SNAPDIR "/.zfs/snapshot/"
+#define ZDIFF_PREFIX "zfs-diff-%d"
+
+#define ZDIFF_ADDED '+'
+#define ZDIFF_MODIFIED "M"
+#define ZDIFF_REMOVED '-'
+#define ZDIFF_RENAMED "R"
+
+#define ZDIFF_ADDED_COLOR ANSI_GREEN
+#define ZDIFF_MODIFIED_COLOR ANSI_YELLOW
+#define ZDIFF_REMOVED_COLOR ANSI_RED
+#define ZDIFF_RENAMED_COLOR ANSI_BOLD_BLUE
+
+/*
+ * Given a {dsname, object id}, get the object path
+ */
+static int
+get_stats_for_obj(differ_info_t *di, const char *dsname, uint64_t obj,
+ char *pn, int maxlen, zfs_stat_t *sb)
+{
+ zfs_cmd_t zc = {"\0"};
+ int error;
+
+ (void) strlcpy(zc.zc_name, dsname, sizeof (zc.zc_name));
+ zc.zc_obj = obj;
+
+ errno = 0;
+ error = zfs_ioctl(di->zhp->zfs_hdl, ZFS_IOC_OBJ_TO_STATS, &zc);
+ di->zerr = errno;
+
+ /* we can get stats even if we failed to get a path */
+ (void) memcpy(sb, &zc.zc_stat, sizeof (zfs_stat_t));
+ if (error == 0) {
+ ASSERT0(di->zerr);
+ (void) strlcpy(pn, zc.zc_value, maxlen);
+ return (0);
+ }
+
+ if (di->zerr == ESTALE) {
+ (void) snprintf(pn, maxlen, "(on_delete_queue)");
+ return (0);
+ } else if (di->zerr == EPERM) {
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "The sys_config privilege or diff delegated permission "
+ "is needed\nto discover path names"));
+ return (-1);
+ } else if (di->zerr == EACCES) {
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "Key must be loaded to discover path names"));
+ return (-1);
+ } else {
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "Unable to determine path or stats for "
+ "object %lld in %s"), (longlong_t)obj, dsname);
+ return (-1);
+ }
+}
+
+/*
+ * stream_bytes
+ *
+ * Prints a file name out a character at a time. If the character is
+ * not in the range of what we consider "printable" ASCII, display it
+ * as an escaped 4-digit octal value. ASCII values less than a space
+ * are all control characters and we declare the upper end as the
+ * DELete character. This also is the last 7-bit ASCII character.
+ * We choose to treat all 8-bit ASCII as not printable for this
+ * application.
+ */
+static void
+stream_bytes(FILE *fp, const char *string)
+{
+ char c;
+
+ while ((c = *string++) != '\0') {
+ if (c > ' ' && c != '\\' && c < '\177') {
+ (void) fputc(c, fp);
+ } else {
+ (void) fprintf(fp, "\\%04hho", (uint8_t)c);
+ }
+ }
+}
+
+/*
+ * Takes the type of change (like `print_file`), outputs the appropriate color
+ */
+static const char *
+type_to_color(char type)
+{
+ if (type == '+')
+ return (ZDIFF_ADDED_COLOR);
+ else if (type == '-')
+ return (ZDIFF_REMOVED_COLOR);
+ else if (type == 'M')
+ return (ZDIFF_MODIFIED_COLOR);
+ else if (type == 'R')
+ return (ZDIFF_RENAMED_COLOR);
+ else
+ return (NULL);
+}
+
+
+static char
+get_what(mode_t what)
+{
+ switch (what & S_IFMT) {
+ case S_IFBLK:
+ return ('B');
+ case S_IFCHR:
+ return ('C');
+ case S_IFDIR:
+ return ('/');
+#ifdef S_IFDOOR
+ case S_IFDOOR:
+ return ('>');
+#endif
+ case S_IFIFO:
+ return ('|');
+ case S_IFLNK:
+ return ('@');
+#ifdef S_IFPORT
+ case S_IFPORT:
+ return ('P');
+#endif
+ case S_IFSOCK:
+ return ('=');
+ case S_IFREG:
+ return ('F');
+ default:
+ return ('?');
+ }
+}
+
+static void
+print_cmn(FILE *fp, differ_info_t *di, const char *file)
+{
+ if (!di->no_mangle) {
+ stream_bytes(fp, di->dsmnt);
+ stream_bytes(fp, file);
+ } else {
+ (void) fputs(di->dsmnt, fp);
+ (void) fputs(file, fp);
+ }
+}
+
+static void
+print_rename(FILE *fp, differ_info_t *di, const char *old, const char *new,
+ zfs_stat_t *isb)
+{
+ if (isatty(fileno(fp)))
+ color_start(ZDIFF_RENAMED_COLOR);
+ if (di->timestamped)
+ (void) fprintf(fp, "%10lld.%09lld\t",
+ (longlong_t)isb->zs_ctime[0],
+ (longlong_t)isb->zs_ctime[1]);
+ (void) fputs(ZDIFF_RENAMED "\t", fp);
+ if (di->classify)
+ (void) fprintf(fp, "%c\t", get_what(isb->zs_mode));
+ print_cmn(fp, di, old);
+ (void) fputs(di->scripted ? "\t" : " -> ", fp);
+ print_cmn(fp, di, new);
+ (void) fputc('\n', fp);
+
+ if (isatty(fileno(fp)))
+ color_end();
+}
+
+static void
+print_link_change(FILE *fp, differ_info_t *di, int delta, const char *file,
+ zfs_stat_t *isb)
+{
+ if (isatty(fileno(fp)))
+ color_start(ZDIFF_MODIFIED_COLOR);
+
+ if (di->timestamped)
+ (void) fprintf(fp, "%10lld.%09lld\t",
+ (longlong_t)isb->zs_ctime[0],
+ (longlong_t)isb->zs_ctime[1]);
+ (void) fputs(ZDIFF_MODIFIED "\t", fp);
+ if (di->classify)
+ (void) fprintf(fp, "%c\t", get_what(isb->zs_mode));
+ print_cmn(fp, di, file);
+ (void) fprintf(fp, "\t(%+d)\n", delta);
+ if (isatty(fileno(fp)))
+ color_end();
+}
+
+static void
+print_file(FILE *fp, differ_info_t *di, char type, const char *file,
+ zfs_stat_t *isb)
+{
+ if (isatty(fileno(fp)))
+ color_start(type_to_color(type));
+
+ if (di->timestamped)
+ (void) fprintf(fp, "%10lld.%09lld\t",
+ (longlong_t)isb->zs_ctime[0],
+ (longlong_t)isb->zs_ctime[1]);
+ (void) fprintf(fp, "%c\t", type);
+ if (di->classify)
+ (void) fprintf(fp, "%c\t", get_what(isb->zs_mode));
+ print_cmn(fp, di, file);
+ (void) fputc('\n', fp);
+
+ if (isatty(fileno(fp)))
+ color_end();
+}
+
+static int
+write_inuse_diffs_one(FILE *fp, differ_info_t *di, uint64_t dobj)
+{
+ struct zfs_stat fsb, tsb;
+ mode_t fmode, tmode;
+ char fobjname[MAXPATHLEN], tobjname[MAXPATHLEN];
+ boolean_t already_logged = B_FALSE;
+ int fobjerr, tobjerr;
+ int change;
+
+ if (dobj == di->shares)
+ return (0);
+
+ /*
+ * Check the from and to snapshots for info on the object. If
+ * we get ENOENT, then the object just didn't exist in that
+ * snapshot. If we get ENOTSUP, then we tried to get
+ * info on a non-ZPL object, which we don't care about anyway.
+ * For any other error we print a warning which includes the
+ * errno and continue.
+ */
+
+ fobjerr = get_stats_for_obj(di, di->fromsnap, dobj, fobjname,
+ MAXPATHLEN, &fsb);
+ if (fobjerr && di->zerr != ENOTSUP && di->zerr != ENOENT) {
+ zfs_error_aux(di->zhp->zfs_hdl, "%s", zfs_strerror(di->zerr));
+ zfs_error(di->zhp->zfs_hdl, di->zerr, di->errbuf);
+ /*
+ * Let's not print an error for the same object more than
+ * once if it happens in both snapshots
+ */
+ already_logged = B_TRUE;
+ }
+
+ tobjerr = get_stats_for_obj(di, di->tosnap, dobj, tobjname,
+ MAXPATHLEN, &tsb);
+
+ if (tobjerr && di->zerr != ENOTSUP && di->zerr != ENOENT) {
+ if (!already_logged) {
+ zfs_error_aux(di->zhp->zfs_hdl,
+ "%s", zfs_strerror(di->zerr));
+ zfs_error(di->zhp->zfs_hdl, di->zerr, di->errbuf);
+ }
+ }
+ /*
+ * Unallocated object sharing the same meta dnode block
+ */
+ if (fobjerr && tobjerr) {
+ di->zerr = 0;
+ return (0);
+ }
+
+ di->zerr = 0; /* negate get_stats_for_obj() from side that failed */
+ fmode = fsb.zs_mode & S_IFMT;
+ tmode = tsb.zs_mode & S_IFMT;
+ if (fmode == S_IFDIR || tmode == S_IFDIR || fsb.zs_links == 0 ||
+ tsb.zs_links == 0)
+ change = 0;
+ else
+ change = tsb.zs_links - fsb.zs_links;
+
+ if (fobjerr) {
+ if (change) {
+ print_link_change(fp, di, change, tobjname, &tsb);
+ return (0);
+ }
+ print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb);
+ return (0);
+ } else if (tobjerr) {
+ if (change) {
+ print_link_change(fp, di, change, fobjname, &fsb);
+ return (0);
+ }
+ print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb);
+ return (0);
+ }
+
+ if (fmode != tmode && fsb.zs_gen == tsb.zs_gen)
+ tsb.zs_gen++; /* Force a generational difference */
+
+ /* Simple modification or no change */
+ if (fsb.zs_gen == tsb.zs_gen) {
+ /* No apparent changes. Could we assert !this? */
+ if (fsb.zs_ctime[0] == tsb.zs_ctime[0] &&
+ fsb.zs_ctime[1] == tsb.zs_ctime[1])
+ return (0);
+ if (change) {
+ print_link_change(fp, di, change,
+ change > 0 ? fobjname : tobjname, &tsb);
+ } else if (strcmp(fobjname, tobjname) == 0) {
+ print_file(fp, di, *ZDIFF_MODIFIED, fobjname, &tsb);
+ } else {
+ print_rename(fp, di, fobjname, tobjname, &tsb);
+ }
+ return (0);
+ } else {
+ /* file re-created or object re-used */
+ print_file(fp, di, ZDIFF_REMOVED, fobjname, &fsb);
+ print_file(fp, di, ZDIFF_ADDED, tobjname, &tsb);
+ return (0);
+ }
+}
+
+static int
+write_inuse_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr)
+{
+ uint64_t o;
+ int err;
+
+ for (o = dr->ddr_first; o <= dr->ddr_last; o++) {
+ if ((err = write_inuse_diffs_one(fp, di, o)) != 0)
+ return (err);
+ }
+ return (0);
+}
+
+static int
+describe_free(FILE *fp, differ_info_t *di, uint64_t object, char *namebuf,
+ int maxlen)
+{
+ struct zfs_stat sb;
+
+ (void) get_stats_for_obj(di, di->fromsnap, object, namebuf,
+ maxlen, &sb);
+
+ /* Don't print if in the delete queue on from side */
+ if (di->zerr == ESTALE || di->zerr == ENOENT) {
+ di->zerr = 0;
+ return (0);
+ }
+
+ print_file(fp, di, ZDIFF_REMOVED, namebuf, &sb);
+ return (0);
+}
+
+static int
+write_free_diffs(FILE *fp, differ_info_t *di, dmu_diff_record_t *dr)
+{
+ zfs_cmd_t zc = {"\0"};
+ libzfs_handle_t *lhdl = di->zhp->zfs_hdl;
+ char fobjname[MAXPATHLEN];
+
+ (void) strlcpy(zc.zc_name, di->fromsnap, sizeof (zc.zc_name));
+ zc.zc_obj = dr->ddr_first - 1;
+
+ ASSERT0(di->zerr);
+
+ while (zc.zc_obj < dr->ddr_last) {
+ int err;
+
+ err = zfs_ioctl(lhdl, ZFS_IOC_NEXT_OBJ, &zc);
+ if (err == 0) {
+ if (zc.zc_obj == di->shares) {
+ zc.zc_obj++;
+ continue;
+ }
+ if (zc.zc_obj > dr->ddr_last) {
+ break;
+ }
+ (void) describe_free(fp, di, zc.zc_obj, fobjname,
+ MAXPATHLEN);
+ } else if (errno == ESRCH) {
+ break;
+ } else {
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "next allocated object (> %lld) find failure"),
+ (longlong_t)zc.zc_obj);
+ di->zerr = errno;
+ break;
+ }
+ }
+ if (di->zerr)
+ return (-1);
+ return (0);
+}
+
+static void *
+differ(void *arg)
+{
+ differ_info_t *di = arg;
+ dmu_diff_record_t dr;
+ FILE *ofp;
+ int err = 0;
+
+ if ((ofp = fdopen(di->outputfd, "w")) == NULL) {
+ di->zerr = errno;
+ strlcpy(di->errbuf, zfs_strerror(errno), sizeof (di->errbuf));
+ (void) close(di->datafd);
+ return ((void *)-1);
+ }
+
+ for (;;) {
+ char *cp = (char *)&dr;
+ int len = sizeof (dr);
+ int rv;
+
+ do {
+ rv = read(di->datafd, cp, len);
+ cp += rv;
+ len -= rv;
+ } while (len > 0 && rv > 0);
+
+ if (rv < 0 || (rv == 0 && len != sizeof (dr))) {
+ di->zerr = EPIPE;
+ break;
+ } else if (rv == 0) {
+ /* end of file at a natural breaking point */
+ break;
+ }
+
+ switch (dr.ddr_type) {
+ case DDR_FREE:
+ err = write_free_diffs(ofp, di, &dr);
+ break;
+ case DDR_INUSE:
+ err = write_inuse_diffs(ofp, di, &dr);
+ break;
+ default:
+ di->zerr = EPIPE;
+ break;
+ }
+
+ if (err || di->zerr)
+ break;
+ }
+
+ (void) fclose(ofp);
+ (void) close(di->datafd);
+ if (err)
+ return ((void *)-1);
+ if (di->zerr) {
+ ASSERT(di->zerr == EPIPE);
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "Internal error: bad data from diff IOCTL"));
+ return ((void *)-1);
+ }
+ return ((void *)0);
+}
+
+static int
+make_temp_snapshot(differ_info_t *di)
+{
+ libzfs_handle_t *hdl = di->zhp->zfs_hdl;
+ zfs_cmd_t zc = {"\0"};
+
+ (void) snprintf(zc.zc_value, sizeof (zc.zc_value),
+ ZDIFF_PREFIX, getpid());
+ (void) strlcpy(zc.zc_name, di->ds, sizeof (zc.zc_name));
+ zc.zc_cleanup_fd = di->cleanupfd;
+
+ if (zfs_ioctl(hdl, ZFS_IOC_TMP_SNAPSHOT, &zc) != 0) {
+ int err = errno;
+ if (err == EPERM) {
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN, "The diff delegated "
+ "permission is needed in order\nto create a "
+ "just-in-time snapshot for diffing\n"));
+ return (zfs_error(hdl, EZFS_DIFF, di->errbuf));
+ } else {
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN, "Cannot create just-in-time "
+ "snapshot of '%s'"), zc.zc_name);
+ return (zfs_standard_error(hdl, err, di->errbuf));
+ }
+ }
+
+ di->tmpsnap = zfs_strdup(hdl, zc.zc_value);
+ di->tosnap = zfs_asprintf(hdl, "%s@%s", di->ds, di->tmpsnap);
+ return (0);
+}
+
+static void
+teardown_differ_info(differ_info_t *di)
+{
+ free(di->ds);
+ free(di->dsmnt);
+ free(di->fromsnap);
+ free(di->frommnt);
+ free(di->tosnap);
+ free(di->tmpsnap);
+ free(di->tomnt);
+ (void) close(di->cleanupfd);
+}
+
+static int
+get_snapshot_names(differ_info_t *di, const char *fromsnap,
+ const char *tosnap)
+{
+ libzfs_handle_t *hdl = di->zhp->zfs_hdl;
+ char *atptrf = NULL;
+ char *atptrt = NULL;
+ int fdslen, fsnlen;
+ int tdslen, tsnlen;
+
+ /*
+ * Can accept
+ * fdslen fsnlen tdslen tsnlen
+ * dataset@snap1
+ * 0. dataset@snap1 dataset@snap2 >0 >1 >0 >1
+ * 1. dataset@snap1 @snap2 >0 >1 ==0 >1
+ * 2. dataset@snap1 dataset >0 >1 >0 ==0
+ * 3. @snap1 dataset@snap2 ==0 >1 >0 >1
+ * 4. @snap1 dataset ==0 >1 >0 ==0
+ */
+ if (tosnap == NULL) {
+ /* only a from snapshot given, must be valid */
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "Badly formed snapshot name %s"), fromsnap);
+
+ if (!zfs_validate_name(hdl, fromsnap, ZFS_TYPE_SNAPSHOT,
+ B_FALSE)) {
+ return (zfs_error(hdl, EZFS_INVALIDNAME,
+ di->errbuf));
+ }
+
+ atptrf = strchr(fromsnap, '@');
+ ASSERT(atptrf != NULL);
+ fdslen = atptrf - fromsnap;
+
+ di->fromsnap = zfs_strdup(hdl, fromsnap);
+ di->ds = zfs_strdup(hdl, fromsnap);
+ di->ds[fdslen] = '\0';
+
+ /* the to snap will be a just-in-time snap of the head */
+ return (make_temp_snapshot(di));
+ }
+
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "Unable to determine which snapshots to compare"));
+
+ atptrf = strchr(fromsnap, '@');
+ atptrt = strchr(tosnap, '@');
+ fdslen = atptrf ? atptrf - fromsnap : strlen(fromsnap);
+ tdslen = atptrt ? atptrt - tosnap : strlen(tosnap);
+ fsnlen = strlen(fromsnap) - fdslen; /* includes @ sign */
+ tsnlen = strlen(tosnap) - tdslen; /* includes @ sign */
+
+ if (fsnlen <= 1 || tsnlen == 1 || (fdslen == 0 && tdslen == 0)) {
+ return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf));
+ } else if ((fdslen > 0 && tdslen > 0) &&
+ ((tdslen != fdslen || strncmp(fromsnap, tosnap, fdslen) != 0))) {
+ /*
+ * not the same dataset name, might be okay if
+ * tosnap is a clone of a fromsnap descendant.
+ */
+ char origin[ZFS_MAX_DATASET_NAME_LEN];
+ zprop_source_t src;
+ zfs_handle_t *zhp;
+
+ di->ds = zfs_alloc(di->zhp->zfs_hdl, tdslen + 1);
+ (void) strlcpy(di->ds, tosnap, tdslen + 1);
+
+ zhp = zfs_open(hdl, di->ds, ZFS_TYPE_FILESYSTEM);
+ while (zhp != NULL) {
+ if (zfs_prop_get(zhp, ZFS_PROP_ORIGIN, origin,
+ sizeof (origin), &src, NULL, 0, B_FALSE) != 0) {
+ (void) zfs_close(zhp);
+ zhp = NULL;
+ break;
+ }
+ if (strncmp(origin, fromsnap, fsnlen) == 0)
+ break;
+
+ (void) zfs_close(zhp);
+ zhp = zfs_open(hdl, origin, ZFS_TYPE_FILESYSTEM);
+ }
+
+ if (zhp == NULL) {
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "Not an earlier snapshot from the same fs"));
+ return (zfs_error(hdl, EZFS_INVALIDNAME, di->errbuf));
+ } else {
+ (void) zfs_close(zhp);
+ }
+
+ di->isclone = B_TRUE;
+ di->fromsnap = zfs_strdup(hdl, fromsnap);
+ if (tsnlen)
+ di->tosnap = zfs_strdup(hdl, tosnap);
+ else
+ return (make_temp_snapshot(di));
+ } else {
+ int dslen = fdslen ? fdslen : tdslen;
+
+ di->ds = zfs_alloc(hdl, dslen + 1);
+ (void) strlcpy(di->ds, fdslen ? fromsnap : tosnap, dslen + 1);
+
+ di->fromsnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrf);
+ if (tsnlen) {
+ di->tosnap = zfs_asprintf(hdl, "%s%s", di->ds, atptrt);
+ } else {
+ return (make_temp_snapshot(di));
+ }
+ }
+ return (0);
+}
+
+static int
+get_mountpoint(differ_info_t *di, char *dsnm, char **mntpt)
+{
+ boolean_t mounted;
+
+ mounted = is_mounted(di->zhp->zfs_hdl, dsnm, mntpt);
+ if (mounted == B_FALSE) {
+ (void) snprintf(di->errbuf, sizeof (di->errbuf),
+ dgettext(TEXT_DOMAIN,
+ "Cannot diff an unmounted snapshot"));
+ return (zfs_error(di->zhp->zfs_hdl, EZFS_BADTYPE, di->errbuf));
+ }
+
+ /* Avoid a double slash at the beginning of root-mounted datasets */
+ if (**mntpt == '/' && *(*mntpt + 1) == '\0')
+ **mntpt = '\0';
+ return (0);
+}
+
+static int
+get_mountpoints(differ_info_t *di)
+{
+ char *strptr;
+ char *frommntpt;
+
+ /*
+ * first get the mountpoint for the parent dataset
+ */
+ if (get_mountpoint(di, di->ds, &di->dsmnt) != 0)
+ return (-1);
+
+ strptr = strchr(di->tosnap, '@');
+ ASSERT3P(strptr, !=, NULL);
+ di->tomnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", di->dsmnt,
+ ZDIFF_SNAPDIR, ++strptr);
+
+ strptr = strchr(di->fromsnap, '@');
+ ASSERT3P(strptr, !=, NULL);
+
+ frommntpt = di->dsmnt;
+ if (di->isclone) {
+ char *mntpt;
+ int err;
+
+ *strptr = '\0';
+ err = get_mountpoint(di, di->fromsnap, &mntpt);
+ *strptr = '@';
+ if (err != 0)
+ return (-1);
+ frommntpt = mntpt;
+ }
+
+ di->frommnt = zfs_asprintf(di->zhp->zfs_hdl, "%s%s%s", frommntpt,
+ ZDIFF_SNAPDIR, ++strptr);
+
+ if (di->isclone)
+ free(frommntpt);
+
+ return (0);
+}
+
+static int
+setup_differ_info(zfs_handle_t *zhp, const char *fromsnap,
+ const char *tosnap, differ_info_t *di)
+{
+ di->zhp = zhp;
+
+ di->cleanupfd = open(ZFS_DEV, O_RDWR | O_CLOEXEC);
+ VERIFY(di->cleanupfd >= 0);
+
+ if (get_snapshot_names(di, fromsnap, tosnap) != 0)
+ return (-1);
+
+ if (get_mountpoints(di) != 0)
+ return (-1);
+
+ if (find_shares_object(di) != 0)
+ return (-1);
+
+ return (0);
+}
+
+int
+zfs_show_diffs(zfs_handle_t *zhp, int outfd, const char *fromsnap,
+ const char *tosnap, int flags)
+{
+ zfs_cmd_t zc = {"\0"};
+ char errbuf[ERRBUFLEN];
+ differ_info_t di = { 0 };
+ pthread_t tid;
+ int pipefd[2];
+ int iocerr;
+
+ (void) snprintf(errbuf, sizeof (errbuf),
+ dgettext(TEXT_DOMAIN, "zfs diff failed"));
+
+ if (setup_differ_info(zhp, fromsnap, tosnap, &di)) {
+ teardown_differ_info(&di);
+ return (-1);
+ }
+
+ if (pipe2(pipefd, O_CLOEXEC)) {
+ zfs_error_aux(zhp->zfs_hdl, "%s", zfs_strerror(errno));
+ teardown_differ_info(&di);
+ return (zfs_error(zhp->zfs_hdl, EZFS_PIPEFAILED, errbuf));
+ }
+
+ di.scripted = (flags & ZFS_DIFF_PARSEABLE);
+ di.classify = (flags & ZFS_DIFF_CLASSIFY);
+ di.timestamped = (flags & ZFS_DIFF_TIMESTAMP);
+ di.no_mangle = (flags & ZFS_DIFF_NO_MANGLE);
+
+ di.outputfd = outfd;
+ di.datafd = pipefd[0];
+
+ if (pthread_create(&tid, NULL, differ, &di)) {
+ zfs_error_aux(zhp->zfs_hdl, "%s", zfs_strerror(errno));
+ (void) close(pipefd[0]);
+ (void) close(pipefd[1]);
+ teardown_differ_info(&di);
+ return (zfs_error(zhp->zfs_hdl,
+ EZFS_THREADCREATEFAILED, errbuf));
+ }
+
+ /* do the ioctl() */
+ (void) strlcpy(zc.zc_value, di.fromsnap, strlen(di.fromsnap) + 1);
+ (void) strlcpy(zc.zc_name, di.tosnap, strlen(di.tosnap) + 1);
+ zc.zc_cookie = pipefd[1];
+
+ iocerr = zfs_ioctl(zhp->zfs_hdl, ZFS_IOC_DIFF, &zc);
+ if (iocerr != 0) {
+ (void) snprintf(errbuf, sizeof (errbuf),
+ dgettext(TEXT_DOMAIN, "Unable to obtain diffs"));
+ if (errno == EPERM) {
+ zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
+ "\n The sys_mount privilege or diff delegated "
+ "permission is needed\n to execute the "
+ "diff ioctl"));
+ } else if (errno == EXDEV) {
+ zfs_error_aux(zhp->zfs_hdl, dgettext(TEXT_DOMAIN,
+ "\n Not an earlier snapshot from the same fs"));
+ } else if (errno != EPIPE || di.zerr == 0) {
+ zfs_error_aux(zhp->zfs_hdl, "%s", zfs_strerror(errno));
+ }
+ (void) close(pipefd[1]);
+ (void) pthread_cancel(tid);
+ (void) pthread_join(tid, NULL);
+ teardown_differ_info(&di);
+ if (di.zerr != 0 && di.zerr != EPIPE) {
+ zfs_error_aux(zhp->zfs_hdl, "%s",
+ zfs_strerror(di.zerr));
+ return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf));
+ } else {
+ return (zfs_error(zhp->zfs_hdl, EZFS_DIFFDATA, errbuf));
+ }
+ }
+
+ (void) close(pipefd[1]);
+ (void) pthread_join(tid, NULL);
+
+ if (di.zerr != 0) {
+ zfs_error_aux(zhp->zfs_hdl, "%s", zfs_strerror(di.zerr));
+ return (zfs_error(zhp->zfs_hdl, EZFS_DIFF, di.errbuf));
+ }
+ teardown_differ_info(&di);
+ return (0);
+}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-09 18:31:01 +0000