If a user attempts to resize a file system to a size under 256MiB,
it will be rejected with EINVAL and get then unhelpful error message
"ERROR: unable to resize '/path': Invalid argument."
This commit performs that check before issuing the ioctl to report
a more sensible error message. We also do overflow/underflow
checking when -/+ size is used and report those errors as well.
Signed-off-by: Jeff Mahoney <jeffm@xxxxxxxx>
---
cmds/filesystem.c | 41 +++++++++++++++++++++++++++++++++++++++++
common/utils.c | 2 +-
common/utils.h | 2 +-
3 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/cmds/filesystem.c b/cmds/filesystem.c
index 4f22089a..e3415126 100644
--- a/cmds/filesystem.c
+++ b/cmds/filesystem.c
@@ -34,10 +34,12 @@
#include "kerncompat.h"
#include "ctree.h"
#include "common/utils.h"
+#include "common/device-utils.h"
#include "volumes.h"
#include "cmds/commands.h"
#include "cmds/filesystem-usage.h"
#include "kernel-lib/list_sort.h"
+#include "kernel-lib/overflow.h"
#include "disk-io.h"
#include "common/help.h"
#include "common/fsfeatures.h"
@@ -1062,6 +1064,41 @@ next:
}
static DEFINE_SIMPLE_COMMAND(filesystem_defrag, "defragment");
+static int check_resize_size(const char *path, const char *amount)
+{
+ int mod = 0;
+ u64 oldsize = 0, size, newsize;
+
+ if (*amount == '-')
+ mod = -1;
+ else if (*amount == '+')
+ mod = 1;
+
+ if (mod) {
+ amount++;
+ oldsize = disk_size(path);
+ if (oldsize == 0)
+ return -1;
+ }
+
+ size = parse_size(amount);
+
+ if (mod == -1 && check_sub_overflow(oldsize, size, &newsize)) {
+ error("can't resize to negative size");
+ return -1;
+ } else if (mod == 1 && check_add_overflow(oldsize, size, &newsize)) {
+ error("can't resize to larger than 16EiB");
+ return -1;
+ } else
+ newsize = size;
+
+ if (newsize < SZ_256M) {
+ error("can't resize to size smaller than 256MiB");
+ return -1;
+ }
+ return 0;
+}
+
static const char * const cmd_filesystem_resize_usage[] = {
"btrfs filesystem resize [devid:][+/-]<newsize>[kKmMgGtTpPeE]|[devid:]max <path>",
"Resize a filesystem",
@@ -1110,6 +1147,10 @@ static int cmd_filesystem_resize(const struct cmd_struct *cmd,
if (fd < 0)
return 1;
+ res = check_resize_size(path, amount);
+ if (res < 0)
+ return 1;
+
printf("Resize '%s' of '%s'\n", path, amount);
memset(&args, 0, sizeof(args));
strncpy_null(args.name, amount);
diff --git a/common/utils.c b/common/utils.c
index ad938409..f2a10ccc 100644
--- a/common/utils.c
+++ b/common/utils.c
@@ -638,7 +638,7 @@ static int fls64(u64 x)
return 64 - i;
}
-u64 parse_size(char *s)
+u64 parse_size(const char *s)
{
char c;
char *endptr;
diff --git a/common/utils.h b/common/utils.h
index 7867fb0a..0ef1d6e8 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -65,7 +65,7 @@ int pretty_size_snprintf(u64 size, char *str, size_t str_bytes, unsigned unit_mo
#define pretty_size(size) pretty_size_mode(size, UNITS_DEFAULT)
const char *pretty_size_mode(u64 size, unsigned mode);
-u64 parse_size(char *s);
+u64 parse_size(const char *s);
u64 parse_qgroupid(const char *p);
u64 arg_strtou64(const char *str);
int open_file_or_dir(const char *fname, DIR **dirstream);
--
2.16.4
