Re: [PATCH] Btrfs-progs: add options to change size in logical to inode transition
From: David Sterba <hidden>
Date: 2012-08-24 16:57:41
On Thu, Aug 23, 2012 at 04:56:28PM +0800, Liu Bo wrote:
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Add an option 's' to set size in logical to inode transition, then we are able to read all the refs to the logical address. Signed-off-by: Liu Bo <redacted> --- cmds-inspect.c | 18 ++++++++++++------ 1 files changed, 12 insertions(+), 6 deletions(-)diff --git a/cmds-inspect.c b/cmds-inspect.c index 2f0228f..be5e588 100644 --- a/cmds-inspect.c +++ b/cmds-inspect.c@@ -115,7 +115,7 @@ static int cmd_inode_resolve(int argc, char **argv) } static const char * const cmd_logical_resolve_usage[] = { - "btrfs inspect-internal logical-resolve [-Pv] <logical> <path>", + "btrfs inspect-internal logical-resolve [-Pv] [-s size] <logical> <path>",
Calling it 'size' si very ambiguous and I needed to go through the code to see where and how the size is actually used. Something like 'bufsize' would be more understandable for a regular user.
"Get file system paths for the given logical address", NULL
and the option should be documented here, saying that if the list is incomplete, user can increase it and the maximum value (when we agree on it)
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};@@ -130,12 +130,13 @@ static int cmd_logical_resolve(int argc, char **argv) int bytes_left; struct btrfs_ioctl_logical_ino_args loi; struct btrfs_data_container *inodes; + u64 size = 4096; char full_path[4096]; char *path_ptr; optind = 1; while (1) { - int c = getopt(argc, argv, "Pv"); + int c = getopt(argc, argv, "Pvs:"); if (c < 0) break;@@ -146,6 +147,9 @@ static int cmd_logical_resolve(int argc, char **argv) case 'v': verbose = 1; break; + case 's': + size = atoll(optarg); + break; default: usage(cmd_logical_resolve_usage); }@@ -154,12 +158,13 @@ static int cmd_logical_resolve(int argc, char **argv) if (check_argc_exact(argc - optind, 2)) usage(cmd_logical_resolve_usage); - inodes = malloc(4096); + size = max(size, 4096); + inodes = malloc(size);
Do we need the sanity checks here as well? Actually, if we avoid the kernel buffer allocation, then user can supply a buffer of any size here and we can drop the upper limit. This would be a bit more future proof, when people will generate not thousands but milions of snapshots :)
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if (!inodes) return 1; loi.logical = atoll(argv[optind]); - loi.size = 4096; + loi.size = size; loi.inodes = (u64)inodes; fd = open_file_or_dir(argv[optind+1]);@@ -176,8 +181,9 @@ static int cmd_logical_resolve(int argc, char **argv) } if (verbose) - printf("ioctl ret=%d, bytes_left=%lu, bytes_missing=%lu, " - "cnt=%d, missed=%d\n", ret, + printf("ioctl ret=%d, total_size=%llu, bytes_left=%lu, " + "bytes_missing=%lu, cnt=%d, missed=%d\n", + ret, size, (unsigned long)inodes->bytes_left, (unsigned long)inodes->bytes_missing, inodes->elem_cnt, inodes->elem_missed);-- 1.7.7.6 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html