[lvm-devel] rhel-9.2.0 - lvresize: fail early if mounted LV was renamed
Marian Csontos
mcsontos at sourceware.org
Thu Feb 9 20:40:49 UTC 2023
Gitweb: https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=fba3614c3ed596b99d8adf2fe6c60886db10b2c0
Commit: fba3614c3ed596b99d8adf2fe6c60886db10b2c0
Parent: 7e0c2e1581225a916269edc8f04fb10e4ef5e952
Author: David Teigland <teigland at redhat.com>
AuthorDate: Thu Jan 26 14:00:00 2023 -0600
Committer: Marian Csontos <mcsontos at redhat.com>
CommitterDate: Thu Feb 9 16:29:38 2023 +0100
lvresize: fail early if mounted LV was renamed
If a mounted LV is renamed, then fs resizing utilities will fail,
so detect this condition and fail the command before any changes
are made.
(cherry picked from commit 5374a44c57127cdd832a675545c1d2bbf0b3751a)
---
lib/device/filesystem.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++
lib/device/filesystem.h | 2 +
lib/metadata/lv_manip.c | 3 ++
test/shell/lvresize-fs.sh | 11 +++++
4 files changed, 126 insertions(+)
diff --git a/lib/device/filesystem.c b/lib/device/filesystem.c
index b4c43a626..db507bdda 100644
--- a/lib/device/filesystem.c
+++ b/lib/device/filesystem.c
@@ -214,6 +214,116 @@ int fs_get_info(struct cmd_context *cmd, struct logical_volume *lv,
return ret;
}
+int fs_mount_state_is_misnamed(struct cmd_context *cmd, struct logical_volume *lv, char *lv_path, char *fstype)
+{
+ FILE *fp;
+ char proc_line[PATH_MAX];
+ char proc_fstype[FSTYPE_MAX];
+ char proc_devpath[1024];
+ char proc_mntpath[1024];
+ char lv_mapper_path[1024];
+ char mntent_mount_dir[1024];
+ char *dm_name;
+ struct stat st_lv;
+ struct stat stme;
+ FILE *fme = NULL;
+ struct mntent *me;
+ int renamed = 0;
+ int found_dir = 0;
+ int found_dev = 0;
+ int dev_match, dir_match;
+
+ if (stat(lv_path, &st_lv) < 0) {
+ log_error("Failed to get LV path %s", lv_path);
+ return 0;
+ }
+
+ /*
+ * If LVs have been renamed while their file systems were mounted, then
+ * inconsistencies appear in the device path and mount point info
+ * provided by getmntent and /proc/mounts. If there's any
+ * inconsistency or duplication of info for the LV name or the mount
+ * point, then give up and don't try fs resize which is likely to fail
+ * due to kernel problems where mounts reference old device names
+ * causing fs resizing tools to fail.
+ */
+
+ if (!(fme = setmntent("/etc/mtab", "r")))
+ return_0;
+
+ while ((me = getmntent(fme))) {
+ if (strcmp(me->mnt_type, fstype))
+ continue;
+ if (me->mnt_dir[0] != '/')
+ continue;
+ if (me->mnt_fsname[0] != '/')
+ continue;
+ if (stat(me->mnt_dir, &stme) < 0)
+ continue;
+ if (stme.st_dev != st_lv.st_rdev)
+ continue;
+ strncpy(mntent_mount_dir, me->mnt_dir, PATH_MAX-1);
+ }
+ endmntent(fme);
+
+ if (!(dm_name = dm_build_dm_name(cmd->mem, lv->vg->name, lv->name, NULL)))
+ return_0;
+
+ if ((dm_snprintf(lv_mapper_path, 1024, "%s/%s", dm_dir(), dm_name) < 0))
+ return_0;
+
+ if (!(fp = fopen("/proc/mounts", "r")))
+ return_0;
+
+ while (fgets(proc_line, sizeof(proc_line), fp)) {
+ if (proc_line[0] != '/')
+ continue;
+ if (sscanf(proc_line, "%s %s %s", proc_devpath, proc_mntpath, proc_fstype) != 3)
+ continue;
+ if (strcmp(fstype, proc_fstype))
+ continue;
+
+ dir_match = !strcmp(mntent_mount_dir, proc_mntpath);
+ dev_match = !strcmp(lv_mapper_path, proc_devpath);
+
+ if (dir_match)
+ found_dir++;
+ if (dev_match)
+ found_dev++;
+
+ if (dir_match != dev_match) {
+ log_error("LV %s mounted at %s may have been renamed (from %s).",
+ lv_mapper_path, proc_mntpath, proc_devpath);
+ renamed = 1;
+ }
+ }
+
+ if (fclose(fp))
+ stack;
+
+ /*
+ * Don't try resizing if:
+ * - different device names apppear for the mount point
+ * (LVs probably renamed while mounted), or
+ * - the mount point for the LV appears multiple times, or
+ * - the LV device is listed for multiple mounts.
+ */
+ if (renamed) {
+ log_error("File system resizing not supported: fs utilities do not support renamed devices.");
+ return 1;
+ }
+ /* These two are likely detected as renamed, but include checks in case. */
+ if (found_dir > 1) {
+ log_error("File system resizing not supported: %s appears more than once in /proc/mounts.", mntent_mount_dir);
+ return 1;
+ }
+ if (found_dev > 1) {
+ log_error("File system resizing not supported: %s appears more than once in /proc/mounts.", lv_mapper_path);
+ return 1;
+ }
+ return 0;
+}
+
#define FS_CMD_MAX_ARGS 16
int crypt_resize_script(struct cmd_context *cmd, struct logical_volume *lv, struct fs_info *fsi,
diff --git a/lib/device/filesystem.h b/lib/device/filesystem.h
index fd1af0416..77eac34d0 100644
--- a/lib/device/filesystem.h
+++ b/lib/device/filesystem.h
@@ -48,4 +48,6 @@ int fs_reduce_script(struct cmd_context *cmd, struct logical_volume *lv, struct
uint64_t newsize_bytes, char *fsmode);
int crypt_resize_script(struct cmd_context *cmd, struct logical_volume *lv, struct fs_info *fsi,
uint64_t newsize_bytes_fs);
+
+int fs_mount_state_is_misnamed(struct cmd_context *cmd, struct logical_volume *lv, char *lv_path, char *fstype);
#endif
diff --git a/lib/metadata/lv_manip.c b/lib/metadata/lv_manip.c
index a2e9db2c9..25e16d41d 100644
--- a/lib/metadata/lv_manip.c
+++ b/lib/metadata/lv_manip.c
@@ -6928,6 +6928,9 @@ int lv_resize(struct cmd_context *cmd, struct logical_volume *lv,
log_error("File system not found for --resizefs or --fs options.");
goto out;
}
+ /* FS utils will fail if LVs were renamed while mounted. */
+ if (fs_mount_state_is_misnamed(cmd, lv_top, lv_path, fstype))
+ goto_out;
}
/*
diff --git a/test/shell/lvresize-fs.sh b/test/shell/lvresize-fs.sh
index 0be6911a0..f437652d6 100644
--- a/test/shell/lvresize-fs.sh
+++ b/test/shell/lvresize-fs.sh
@@ -262,6 +262,17 @@ umount "$mount_dir"
lvchange -an $vg/$lv
lvremove $vg/$lv
+# lvextend|lvreduce, ext4, active, mounted, --fs resize, renamed LV
+lvcreate -n $lv -L 256M $vg
+mkfs.ext4 "$DM_DEV_DIR/$vg/$lv"
+mount "$DM_DEV_DIR/$vg/$lv" "$mount_dir"
+lvrename $vg/$lv $vg/$lv2
+not lvextend --fs resize -L+32M $vg/$lv2
+not lvreduce --fs resize -L-32M $vg/$lv2
+umount "$mount_dir"
+lvchange -an $vg/$lv2
+lvremove $vg/$lv2
+
#
# lvextend, xfs
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