Btrfs-progs: add options to change bufsize in logical to inode translation

Add an option 's' to set bufsize in logical to inode transition, then we are able
to read all the refs to the logical address.
Meanwhile, set a max value 64k for the bufsize.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

2 files changed, 22 insertions, 8 deletions

diff --git a/cmds-inspect.c b/cmds-inspect.c
index 376fab28..4e072b0a 100644
--- a/cmds-inspect.c
+++ b/cmds-inspect.c
@@ -113,8 +113,13 @@ 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 bufsize] <logical> <path>",
 	"Get file system paths for the given logical address",
+	"-P          skip the path resolving and print the inodes instead",
+	"-v          verbose mode",
+	"-s bufsize  set inode container's size. This is used to increase inode",
+	"            container's size in case it is not enough to read all the ",
+	"            resolved results. The max value one can set is 64k",
 	NULL
 };
 
@@ -128,12 +133,13 @@ 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;
 
@@ -144,6 +150,9 @@ 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);
 		}
@@ -152,12 +161,13 @@ 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 = min(size, 64 * 1024);
+	inodes = malloc(size);
 	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]);
@@ -174,8 +184,9 @@ 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);
diff --git a/man/btrfs.8.in b/man/btrfs.8.in
index a8b4e9dc..92225800 100644
--- a/man/btrfs.8.in
+++ b/man/btrfs.8.in
@@ -50,7 +50,7 @@ btrfs \- control a btrfs filesystem
 \fBbtrfs\fP \fBinspect-internal inode-resolve\fP [-v] \fI<inode>\fP \fI<path>\fP
 .PP
 \fBbtrfs\fP \fBinspect-internal logical-resolve\fP
-[-Pv] \fI<logical>\fP \fI<path>\fP
+[-Pv] [-s size] \fI<logical>\fP \fI<path>\fP
 .PP
 \fBbtrfs\fP \fBhelp|\-\-help|\-h \fP\fI\fP
 .PP
@@ -335,7 +335,7 @@ verbose mode. print count of returned paths and ioctl() return value
 .RE
 .TP
 
-\fBinspect-internal logical-resolve\fP [-Pv] \fI<logical>\fP \fI<path>\fP
+\fBinspect-internal logical-resolve\fP [-Pv] [-s bufsize] \fI<logical>\fP \fI<path>\fP
 Resolves a <logical> address in the filesystem mounted at <path> to all inodes.
 By default, each inode is then resolved to a file system path (similar to the
 \fBinode-resolve\fP subcommand).
@@ -346,6 +346,9 @@ By default, each inode is then resolved to a file system path (similar to the
 skip the path resolving and print the inodes instead
 .IP -v 5
 verbose mode. print count of returned paths and all ioctl() return values
+.IP -s bufsize 5
+set inode container's size. This is used to increase inode container's size in case it is
+not enough to read all the resolved results. The max value one can set is 64k.
 .RE
 
 .SH EXIT STATUS