Patchwork [4/4] e2image: handle SIGINT safely

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Submitter Phillip Susi
Date Oct. 8, 2013, 3:56 p.m.
Message ID <1381247792-22508-5-git-send-email-psusi@ubuntu.com>
Download mbox | patch
Permalink /patch/281507/
State Superseded
Headers show

Comments

Phillip Susi - Oct. 8, 2013, 3:56 p.m.
When doing an in place move, interrupting it past the
point of no return will destroy the filesystem since
parts of it have been overwritten.  Catch SIGINT the
first time and issue a warning if this is the case.

Signed-off-by: Phillip Susi <psusi@ubuntu.com>
---
 misc/e2image.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
Theodore Ts'o - Dec. 25, 2013, 4:58 a.m.
On Tue, Oct 08, 2013 at 11:56:32AM -0400, Phillip Susi wrote:
> When doing an in place move, interrupting it past the
> point of no return will destroy the filesystem since
> parts of it have been overwritten.  Catch SIGINT the
> first time and issue a warning if this is the case.
> 
> Signed-off-by: Phillip Susi <psusi@ubuntu.com>

Thanks, applied.

					- Ted
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Patch

diff --git a/misc/e2image.c b/misc/e2image.c
index 27be2b1..2340f15 100644
--- a/misc/e2image.c
+++ b/misc/e2image.c
@@ -35,6 +35,7 @@  extern int optind;
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <assert.h>
+#include <signal.h>
 
 #include "ext2fs/ext2_fs.h"
 #include "ext2fs/ext2fs.h"
@@ -484,6 +485,14 @@  static void scramble_dir_block(ext2_filsys fs, blk64_t blk, char *buf)
 	}
 }
 
+static char got_sigint;
+
+static void sigint_handler(int unsused)
+{
+	got_sigint = 1;
+	signal (SIGINT, SIG_DFL);
+}
+
 static void output_meta_data_blocks(ext2_filsys fs, int fd)
 {
 	errcode_t	retval;
@@ -527,10 +536,39 @@  static void output_meta_data_blocks(ext2_filsys fs, int fd)
 		if (distance < ext2fs_blocks_count(fs->super))
 			start = ext2fs_blocks_count(fs->super) - distance;
 	}
+	if (move_mode)
+		signal (SIGINT, sigint_handler);
 more_blocks:
 	if (distance)
 		ext2fs_llseek (fd, (start * fs->blocksize) + dest_offset, SEEK_SET);
 	for (blk = start; blk < end; blk++) {
+		if (got_sigint) {
+			if (distance) {
+				/* moving to the right */
+				if (distance >= ext2fs_blocks_count(fs->super) ||
+				    start == ext2fs_blocks_count(fs->super) - distance)
+					kill (getpid(), SIGINT);
+			} else {
+				/* moving to the left */
+				if (blk < (source_offset - dest_offset) / fs->blocksize)
+					kill (getpid(), SIGINT);
+			}
+			if (show_progress)
+				printf ("\r");
+			printf ("Stopping now will destroy the filesystem, "
+				"interrupt again if you are sure\n");
+			if (show_progress) {
+				printf("Copying ");
+				bscount = printf("%llu / %llu blocks (%llu%%)",
+						 total_written,
+						 meta_blocks_count,
+						 (total_written + 50) / ((meta_blocks_count + 50)
+									 / 100));
+				fflush(stdout);
+			}
+
+			got_sigint = 0;
+		}
 		if (show_progress && last_update != time(NULL)) {
 			last_update = time(NULL);
 			while (bscount--)
@@ -600,6 +638,7 @@  more_blocks:
 		sparse = 0;
 		goto more_blocks;
 	}
+	signal (SIGINT, SIG_DFL);
 	if (show_progress) {
 		while (bscount--)
 			printf("\b");