ext4: fix uniniatilized extent splitting error
authorDmitry Monakhov <dmonakhov@openvz.org>
Tue, 29 Jan 2008 04:58:27 +0000 (23:58 -0500)
committerTheodore Ts'o <tytso@mit.edu>
Tue, 29 Jan 2008 04:58:27 +0000 (23:58 -0500)
Fix bug reported by Dmitry Monakhov caused by lost error code

    Testcase:

    blksize = 0x1000;
    fd = open(argv[1], O_RDWR|O_CREAT, 0700);
    unsigned long long sz = 0x10000000UL;
    /* allocating big blocks chunk */
    syscall(__NR_fallocate, fd, 0, 0UL, sz)

    /* grab all other available filesystem space */
    tfd = open("tmp", O_RDWR|O_CREAT|O_DIRECT, 0700);
    while( write(tfd, buf, 4096) > 0); /* loop untill ENOSPC */
    fsync(fd); /* just in case */
    while (pos < sz) {
     /* each seek+ write operation result in splits uninitialized extent
     in three extents. Splitting may result in new extent allocation
     which probably will fail because of ENOSPC*/

     lseek(fd, blksize*2 -1, SEEK_CUR);
     if ((ret = write(fd, 'a', 1)) != 1)
     exit(1);
     pos += blksize * 2;
    }

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
fs/ext4/extents.c

index 0cffb59fff46853f52e0f21684507a7dafb5d6fc..ce9aa5860569a3120c0ecf6ba16fd20f72bb2218 100644 (file)
@@ -2373,9 +2373,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
                        ret = ext4_ext_convert_to_initialized(handle, inode,
                                                                path, iblock,
                                                                max_blocks);
-                       if (ret <= 0)
+                       if (ret <= 0) {
+                               err = ret;
                                goto out2;
-                       else
+                       else
                                allocated = ret;
                        goto outnew;
                }