2013-09-27 19:01:41

by Carlos Maiolino

[permalink] [raw]
Subject: [PATCH] e2image: Print a warning if running over a mounted filesystem

Several users use to run e2image over a mounted RW filesystem, providing
inconsistent, useless e2images for debugging purposes.
This patch adds a warning in such cases, notifying the user and also adds a
force option making e2image able to run in such cases.
Also print a warning when not using qcow or raw formats but allows image
creation to proceed, since, such images might be used for metadata backup
purposes.

Signed-off-by: Carlos Maiolino <[email protected]>
---
misc/e2image.c | 34 ++++++++++++++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/misc/e2image.c b/misc/e2image.c
index 885a794..e467301 100644
--- a/misc/e2image.c
+++ b/misc/e2image.c
@@ -87,7 +87,7 @@ static int get_bits_from_size(size_t size)

static void usage(void)
{
- fprintf(stderr, _("Usage: %s [-rsIQa] device image_file\n"),
+ fprintf(stderr, _("Usage: %s [-rsIQaf] device image_file\n"),
program_name);
exit (1);
}
@@ -1252,9 +1252,11 @@ int main (int argc, char ** argv)
int open_flag = EXT2_FLAG_64BITS;
int img_type = 0;
int flags = 0;
+ int mount_flags = 0;
int qcow2_fd = 0;
int fd = 0;
int ret = 0;
+ int ignore_rw_mount = 0;
struct stat st;

#ifdef ENABLE_NLS
@@ -1269,7 +1271,7 @@ int main (int argc, char ** argv)
if (argc && *argv)
program_name = *argv;
add_error_table(&et_ext2_error_table);
- while ((c = getopt(argc, argv, "rsIQa")) != EOF)
+ while ((c = getopt(argc, argv, "rsIQaf")) != EOF)
switch (c) {
case 'I':
flags |= E2IMAGE_INSTALL_FLAG;
@@ -1290,6 +1292,9 @@ int main (int argc, char ** argv)
case 'a':
all_data = 1;
break;
+ case 'f':
+ ignore_rw_mount = 1;
+ break;
default:
usage();
}
@@ -1305,6 +1310,31 @@ int main (int argc, char ** argv)
device_name = argv[optind];
image_fn = argv[optind+1];

+ ext2fs_check_if_mounted(device_name, &mount_flags);
+
+ if ((mount_flags & EXT2_MF_MOUNTED) &&
+ !(mount_flags & EXT2_MF_READONLY)) {
+ fprintf(stderr, "\nWarning: Running e2image on a mounted "
+ "RW filesystem can result in an inconsistent "
+ "image which will not be useful for "
+ "debugging purposes.\n");
+ /*
+ * A force is required here once qcow and raw image
+ * formats (img_type is set) are mostly used for
+ * debugging purposes, while, a "normal" image is
+ * usually collected for metadata backup.
+ *
+ * An inconsistent image is almost useless for
+ * debugging, so we ensure the filesystem is read-only
+ * before continue (unless the user force the image creation)
+ */
+ if (img_type && !ignore_rw_mount) {
+ fprintf(stderr, "Use -f option if you really want to "
+ "do that.\n");
+ exit(1);
+ }
+ }
+
if (flags & E2IMAGE_INSTALL_FLAG) {
install_image(device_name, image_fn, img_type);
exit (0);
--
1.8.1.4



2013-09-27 20:01:04

by Carlos Maiolino

[permalink] [raw]
Subject: Re: [PATCH] e2image: Print a warning if running over a mounted filesystem

I'm so Sorry, I forgot to add a V3 tag in the subject

On Fri, Sep 27, 2013 at 04:01:35PM -0300, Carlos Maiolino wrote:
> Several users use to run e2image over a mounted RW filesystem, providing
> inconsistent, useless e2images for debugging purposes.
> This patch adds a warning in such cases, notifying the user and also adds a
> force option making e2image able to run in such cases.
> Also print a warning when not using qcow or raw formats but allows image
> creation to proceed, since, such images might be used for metadata backup
> purposes.
>
> Signed-off-by: Carlos Maiolino <[email protected]>
> ---
> misc/e2image.c | 34 ++++++++++++++++++++++++++++++++--
> 1 file changed, 32 insertions(+), 2 deletions(-)
>
> diff --git a/misc/e2image.c b/misc/e2image.c
> index 885a794..e467301 100644
> --- a/misc/e2image.c
> +++ b/misc/e2image.c
> @@ -87,7 +87,7 @@ static int get_bits_from_size(size_t size)
>
> static void usage(void)
> {
> - fprintf(stderr, _("Usage: %s [-rsIQa] device image_file\n"),
> + fprintf(stderr, _("Usage: %s [-rsIQaf] device image_file\n"),
> program_name);
> exit (1);
> }
> @@ -1252,9 +1252,11 @@ int main (int argc, char ** argv)
> int open_flag = EXT2_FLAG_64BITS;
> int img_type = 0;
> int flags = 0;
> + int mount_flags = 0;
> int qcow2_fd = 0;
> int fd = 0;
> int ret = 0;
> + int ignore_rw_mount = 0;
> struct stat st;
>
> #ifdef ENABLE_NLS
> @@ -1269,7 +1271,7 @@ int main (int argc, char ** argv)
> if (argc && *argv)
> program_name = *argv;
> add_error_table(&et_ext2_error_table);
> - while ((c = getopt(argc, argv, "rsIQa")) != EOF)
> + while ((c = getopt(argc, argv, "rsIQaf")) != EOF)
> switch (c) {
> case 'I':
> flags |= E2IMAGE_INSTALL_FLAG;
> @@ -1290,6 +1292,9 @@ int main (int argc, char ** argv)
> case 'a':
> all_data = 1;
> break;
> + case 'f':
> + ignore_rw_mount = 1;
> + break;
> default:
> usage();
> }
> @@ -1305,6 +1310,31 @@ int main (int argc, char ** argv)
> device_name = argv[optind];
> image_fn = argv[optind+1];
>
> + ext2fs_check_if_mounted(device_name, &mount_flags);
> +
> + if ((mount_flags & EXT2_MF_MOUNTED) &&
> + !(mount_flags & EXT2_MF_READONLY)) {
> + fprintf(stderr, "\nWarning: Running e2image on a mounted "
> + "RW filesystem can result in an inconsistent "
> + "image which will not be useful for "
> + "debugging purposes.\n");
> + /*
> + * A force is required here once qcow and raw image
> + * formats (img_type is set) are mostly used for
> + * debugging purposes, while, a "normal" image is
> + * usually collected for metadata backup.
> + *
> + * An inconsistent image is almost useless for
> + * debugging, so we ensure the filesystem is read-only
> + * before continue (unless the user force the image creation)
> + */
> + if (img_type && !ignore_rw_mount) {
> + fprintf(stderr, "Use -f option if you really want to "
> + "do that.\n");
> + exit(1);
> + }
> + }
> +
> if (flags & E2IMAGE_INSTALL_FLAG) {
> install_image(device_name, image_fn, img_type);
> exit (0);
> --
> 1.8.1.4
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Carlos

2013-09-30 20:24:43

by Theodore Ts'o

[permalink] [raw]
Subject: Re: [PATCH] e2image: Print a warning if running over a mounted filesystem

On Fri, Sep 27, 2013 at 04:01:35PM -0300, Carlos Maiolino wrote:
> Several users use to run e2image over a mounted RW filesystem, providing
> inconsistent, useless e2images for debugging purposes.
> This patch adds a warning in such cases, notifying the user and also adds a
> force option making e2image able to run in such cases.
> Also print a warning when not using qcow or raw formats but allows image
> creation to proceed, since, such images might be used for metadata backup
> purposes.
>
> Signed-off-by: Carlos Maiolino <[email protected]>

This looks good to me; go ahead and update the man page. :-)

- Ted

2013-09-30 20:35:41

by Carlos Maiolino

[permalink] [raw]
Subject: Re: [PATCH] e2image: Print a warning if running over a mounted filesystem

Roger,

should send a manpage update today yet

Cheers, and thanks for the review eric and ted
On Mon, Sep 30, 2013 at 04:24:39PM -0400, Theodore Ts'o wrote:
> On Fri, Sep 27, 2013 at 04:01:35PM -0300, Carlos Maiolino wrote:
> > Several users use to run e2image over a mounted RW filesystem, providing
> > inconsistent, useless e2images for debugging purposes.
> > This patch adds a warning in such cases, notifying the user and also adds a
> > force option making e2image able to run in such cases.
> > Also print a warning when not using qcow or raw formats but allows image
> > creation to proceed, since, such images might be used for metadata backup
> > purposes.
> >
> > Signed-off-by: Carlos Maiolino <[email protected]>
>
> This looks good to me; go ahead and update the man page. :-)
>
> - Ted
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to [email protected]
> More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Carlos