On 01/23/2011 07:18 PM, Hugo Mills wrote: > Hi, Felix, > > On Sat, Jan 22, 2011 at 04:56:12PM +0100, Felix Blanke wrote: >> It was a simple: >> >> mkfs.btrfs -L backup -d single /dev/loop2 >> >> But it also happens without the options, like: >> >> mkfs.btrfs /dev/loop2 >> >> >> /dev/loop2 is a loop device, which is aes encrypted. The output of "losetup /dev/loop2": >> >> /dev/loop2: [0010]:5324 >> (/dev/disk/by-id/ata-WDC_WD6400AAKS-22A7B2_WD-WCASY7780706-part3) encryption=AES128 >> >> >> Thanks you for looking into this! >> While writing this I read your second mail. The strace output is attached. > > OK, I've traced through the functions being called, and I really > can't see where it could be truncating the name, unless your system > has a stupidly small value of PATH_MAX. It seems that when mkfs.btrfs checks if the passed block device is already mounted, uses the ioctl LOOP_GET_STATUS [1]. This ioctl has as argument the struct loop_info. This ioctl, should return the info about the back-end of the loop device. The file name is returned via the "lo_name" field, which is an array of 64 char...[2] Felix, what is the output of the following command ? /sbin/losetup -a If my analysis is correct, this command should return the filename trunked at the 64th character too. Goffredo [1] file util.c, function resolve_loop_device [2] http://lxr.e2g.org/source/bionic/libc/kernel/common/linux/loop.h?a=ppc#L26 and http://lxr.e2g.org/source/bionic/libc/kernel/common/linux/loop.h?a=ppc#L15 > > Can you apply the following patch (to the "next" branch of the > btrfs-progs git repo), rebuild, and try again? It's just adding some > debugging output to track what it's looking at. > > Hugo. > > > diff --git a/mkfs.c b/mkfs.c > index 2e99b95..51a5096 100644 > --- a/mkfs.c > +++ b/mkfs.c > @@ -422,6 +422,7 @@ int main(int ac, char **av) > printf("WARNING! - see http://btrfs.wiki.kernel.org before using\n\n"); > > file = av[optind++]; > + printf("Checking whether %s is part of a mounted filesystem\n", file); > ret = check_mounted(file); > if (ret < 0) { > fprintf(stderr, "error checking %s mount status\n", file); > diff --git a/utils.c b/utils.c > index fd894f3..7fa3149 100644 > --- a/utils.c > +++ b/utils.c > @@ -610,12 +610,16 @@ int resolve_loop_device(const char* loop_dev, char* loop_file, int max_len) > int ret_ioctl; > struct loop_info loopinfo; > > + printf("Resolving loop device %s (length %d)\n", loop_dev, max_len); > + > if ((loop_fd = open(loop_dev, O_RDONLY)) < 0) > return -errno; > > ret_ioctl = ioctl(loop_fd, LOOP_GET_STATUS, &loopinfo); > close(loop_fd); > > + printf("Loop name = %s\n", loopinfo.lo_name); > + > if (ret_ioctl == 0) > strncpy(loop_file, loopinfo.lo_name, max_len); > else > @@ -639,6 +643,9 @@ int is_same_blk_file(const char* a, const char* b) > return -errno; > } > > + printf("Realpath of %s was %s\n", a, real_a); > + printf("Realpath of %s was %s\n", b, real_b); > + > /* Identical path? */ > if(strcmp(real_a, real_b) == 0) > return 1; > @@ -680,6 +687,9 @@ int is_same_loop_file(const char* a, const char* b) > const char* final_b; > int ret; > > + printf("is_same_loop_file: %s and %s\n", a, b); > + printf("PATH_MAX = %d\n", PATH_MAX); > + > /* Resolve a if it is a loop device */ > if((ret = is_loop_device(a)) < 0) { > return ret; > @@ -784,8 +794,10 @@ int check_mounted(const char* file) > if(strcmp(mnt->mnt_type, "btrfs") != 0) > continue; > > + printf("Testing if btrfs device is in the dev list: %s\n", mnt->mnt_fsname); > ret = blk_file_in_dev_list(fs_devices_mnt, mnt->mnt_fsname); > } else { > + printf("Testing if non-btrfs device is block or regular: %s\n", mnt->mnt_fsname); > /* ignore entries in the mount table that are not > associated with a file*/ > if((ret = is_existing_blk_or_reg_file(mnt->mnt_fsname)) < 0) > diff --git a/volumes.c b/volumes.c > index 7671855..2496fbd 100644 > --- a/volumes.c > +++ b/volumes.c > @@ -130,6 +130,8 @@ static int device_list_add(const char *path, > device->fs_devices = fs_devices; > } > > + printf("Device added with name %s\n", device->name); > + > if (found_transid > fs_devices->latest_trans) { > fs_devices->latest_devid = devid; > fs_devices->latest_trans = found_transid; > @@ -223,6 +225,7 @@ int btrfs_scan_one_device(int fd, const char *path, > *total_devs = btrfs_super_num_devices(disk_super); > uuid_unparse(disk_super->fsid, uuidbuf); > > + printf("Adding device %s to list\n", path); > ret = device_list_add(path, disk_super, devid, fs_devices_ret); > > error_brelse: > > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
