Re: [PATCH v2] btrfs-progs: filesystem-resize: make output more readable
From: David Sterba <hidden>
Date: 2021-02-19 13:47:03
On Sat, Jan 23, 2021 at 03:37:20PM +0000, Sidong Yang wrote:
quoted hunk ↗ jump to hunk
This patch make output of filesystem-resize command more readable and give detail information for users. This patch provides more information about filesystem like below. Before: Resize '/mnt' of '1:-1G' After: Resize device id 1 (/dev/vdb) from 4.00GiB to 3.00GiB Signed-off-by: Sidong Yang <redacted> --- v2: - print more detailed error - covers all the possibilities format provides --- cmds/filesystem.c | 112 +++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 111 insertions(+), 1 deletion(-)diff --git a/cmds/filesystem.c b/cmds/filesystem.c index ba2e5928..cec3f380 100644 --- a/cmds/filesystem.c +++ b/cmds/filesystem.c@@ -28,6 +28,7 @@ #include <linux/limits.h> #include <linux/version.h> #include <getopt.h> +#include <limits.h> #include <btrfsutil.h>@@ -1074,6 +1075,109 @@ static const char * const cmd_filesystem_resize_usage[] = { NULL }; +static int check_resize_args(const char *amount, const char *path) { + struct btrfs_ioctl_fs_info_args fi_args; + struct btrfs_ioctl_dev_info_args *di_args = NULL; + int ret, i, devid = 0, dev_idx = -1;
devid should be u64
+ const char *res_str = NULL; + char *devstr = NULL, *sizestr = NULL; + u64 new_size = 0, old_size = 0; + int mod = 0; + char amount_dup[BTRFS_VOL_NAME_MAX];
Bffer of a fixed size ...
+
+ ret = get_fs_info(path, &fi_args, &di_args);
+
+ if (ret) {
+ error("unable to retrieve fs info");
+ return 1;
+ }
+
+ if (!fi_args.num_devices) {
+ error("no devices found");
+ free(di_args);
+ return 1;
+ }
+
+ strcpy(amount_dup, amount);... and strcpy from a user specified buffer, this is from chapter 1 of how buffer overflows in C work. Please use safe string copy.
+ devstr = strchr(amount_dup, ':');
+ if (devstr) {
+ sizestr = devstr + 1;
+ *devstr = '\0';
+ devstr = amount_dup;
+
+ errno = 0;
+ devid = strtoull(devstr, NULL, 10);
+
+ if (errno) {
+ error("failed to parse devid %s", devstr);
+ free(di_args);
+ return 1;
+ }
+ }
+
+ dev_idx = -1;
+ for(i = 0; i < fi_args.num_devices; i++) {
+ if (di_args[i].devid == devid) {
+ dev_idx = i;
+ break;
+ }
+ }
+
+ if (dev_idx < 0) {
+ error("cannot find devid : %d", devid);
+ free(di_args);
+ return 1;
+ }
+
+ if (!strcmp(sizestr, "max")) {
+ res_str = "max";
+ }
+ else {
+ if (sizestr[0] == '-') {
+ mod = -1;
+ sizestr++;
+ } else if (sizestr[0] == '+') {
+ mod = 1;
+ sizestr++;
+ }
+ new_size = parse_size(sizestr);
+ if (!new_size) {
+ error("failed to parse size %s", sizestr);
+ free(di_args);
+ return 1;
+ }
+ old_size = di_args[dev_idx].total_bytes;
+
+ if (mod < 0) {
+ if (new_size > old_size) {
+ error("current size is %s which is smaller than %s",
+ pretty_size_mode(old_size, UNITS_DEFAULT),
+ pretty_size_mode(new_size, UNITS_DEFAULT));
+ free(di_args);
+ return 1;
+ }
+ new_size = old_size - new_size;
+ } else if (mod > 0) {
+ if (new_size > ULLONG_MAX - old_size) {
+ error("increasing %s is out of range",
+ pretty_size_mode(new_size, UNITS_DEFAULT));
+ free(di_args);
+ return 1;
+ }
+ new_size = old_size + new_size;This all got me confused, old_size and new_size sound like absolute numbers for the size but new_size is in fact used as the delta, or the relative change. Otherwise looks good.
quoted hunk ↗ jump to hunk
+ } + new_size = round_down(new_size, fi_args.sectorsize); + res_str = pretty_size_mode(new_size, UNITS_DEFAULT); + } + + printf("Resize device id %d (%s) from %s to %s\n", devid, di_args[dev_idx].path, + pretty_size_mode(di_args[dev_idx].total_bytes, UNITS_DEFAULT), + res_str); + + free(di_args); + return 0; +} + static int cmd_filesystem_resize(const struct cmd_struct *cmd, int argc, char **argv) {@@ -1139,7 +1243,13 @@ static int cmd_filesystem_resize(const struct cmd_struct *cmd, return 1; } - printf("Resize '%s' of '%s'\n", path, amount); + ret = check_resize_args(path, amount); + if (ret != 0) { + close_file_or_dir(fd, dirstream); + return 1; + } + + memset(&args, 0, sizeof(args)); strncpy_null(args.name, amount); res = ioctl(fd, BTRFS_IOC_RESIZE, &args);-- 2.25.1