btrfs-progs: move mkfs helper implementation out of utils

Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 283 insertions, 0 deletions

diff --git a/mkfs/common.c b/mkfs/common.c
index 588712d7..8d92eae2 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -16,6 +16,8 @@
 
 #include <unistd.h>
 #include <uuid/uuid.h>
+#include <blkid/blkid.h>
+#include <fcntl.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "volumes.h"
@@ -437,3 +439,284 @@ out:
 	return ret;
 }
 
+u64 btrfs_min_dev_size(u32 nodesize)
+{
+	return 2 * (BTRFS_MKFS_SYSTEM_GROUP_SIZE +
+		    btrfs_min_global_blk_rsv_size(nodesize));
+}
+
+/*
+ * Btrfs minimum size calculation is complicated, it should include at least:
+ * 1. system group size
+ * 2. minimum global block reserve
+ * 3. metadata used at mkfs
+ * 4. space reservation to create uuid for first mount.
+ * Also, raid factor should also be taken into consideration.
+ * To avoid the overkill calculation, (system group + global block rsv) * 2
+ * for *EACH* device should be good enough.
+ */
+u64 btrfs_min_global_blk_rsv_size(u32 nodesize)
+{
+	return (u64)nodesize << 10;
+}
+
+#define isoctal(c)	(((c) & ~7) == '0')
+
+static inline void translate(char *f, char *t)
+{
+	while (*f != '\0') {
+		if (*f == '\\' &&
+		    isoctal(f[1]) && isoctal(f[2]) && isoctal(f[3])) {
+			*t++ = 64*(f[1] & 7) + 8*(f[2] & 7) + (f[3] & 7);
+			f += 4;
+		} else
+			*t++ = *f++;
+	}
+	*t = '\0';
+	return;
+}
+
+/*
+ * Checks if the swap device.
+ * Returns 1 if swap device, < 0 on error or 0 if not swap device.
+ */
+static int is_swap_device(const char *file)
+{
+	FILE	*f;
+	struct stat	st_buf;
+	dev_t	dev;
+	ino_t	ino = 0;
+	char	tmp[PATH_MAX];
+	char	buf[PATH_MAX];
+	char	*cp;
+	int	ret = 0;
+
+	if (stat(file, &st_buf) < 0)
+		return -errno;
+	if (S_ISBLK(st_buf.st_mode))
+		dev = st_buf.st_rdev;
+	else if (S_ISREG(st_buf.st_mode)) {
+		dev = st_buf.st_dev;
+		ino = st_buf.st_ino;
+	} else
+		return 0;
+
+	if ((f = fopen("/proc/swaps", "r")) == NULL)
+		return 0;
+
+	/* skip the first line */
+	if (fgets(tmp, sizeof(tmp), f) == NULL)
+		goto out;
+
+	while (fgets(tmp, sizeof(tmp), f) != NULL) {
+		if ((cp = strchr(tmp, ' ')) != NULL)
+			*cp = '\0';
+		if ((cp = strchr(tmp, '\t')) != NULL)
+			*cp = '\0';
+		translate(tmp, buf);
+		if (stat(buf, &st_buf) != 0)
+			continue;
+		if (S_ISBLK(st_buf.st_mode)) {
+			if (dev == st_buf.st_rdev) {
+				ret = 1;
+				break;
+			}
+		} else if (S_ISREG(st_buf.st_mode)) {
+			if (dev == st_buf.st_dev && ino == st_buf.st_ino) {
+				ret = 1;
+				break;
+			}
+		}
+	}
+
+out:
+	fclose(f);
+
+	return ret;
+}
+
+/*
+ * Check for existing filesystem or partition table on device.
+ * Returns:
+ *	 1 for existing fs or partition
+ *	 0 for nothing found
+ *	-1 for internal error
+ */
+static int check_overwrite(const char *device)
+{
+	const char	*type;
+	blkid_probe	pr = NULL;
+	int		ret;
+	blkid_loff_t	size;
+
+	if (!device || !*device)
+		return 0;
+
+	ret = -1; /* will reset on success of all setup calls */
+
+	pr = blkid_new_probe_from_filename(device);
+	if (!pr)
+		goto out;
+
+	size = blkid_probe_get_size(pr);
+	if (size < 0)
+		goto out;
+
+	/* nothing to overwrite on a 0-length device */
+	if (size == 0) {
+		ret = 0;
+		goto out;
+	}
+
+	ret = blkid_probe_enable_partitions(pr, 1);
+	if (ret < 0)
+		goto out;
+
+	ret = blkid_do_fullprobe(pr);
+	if (ret < 0)
+		goto out;
+
+	/*
+	 * Blkid returns 1 for nothing found and 0 when it finds a signature,
+	 * but we want the exact opposite, so reverse the return value here.
+	 *
+	 * In addition print some useful diagnostics about what actually is
+	 * on the device.
+	 */
+	if (ret) {
+		ret = 0;
+		goto out;
+	}
+
+	if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
+		fprintf(stderr,
+			"%s appears to contain an existing "
+			"filesystem (%s).\n", device, type);
+	} else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
+		fprintf(stderr,
+			"%s appears to contain a partition "
+			"table (%s).\n", device, type);
+	} else {
+		fprintf(stderr,
+			"%s appears to contain something weird "
+			"according to blkid\n", device);
+	}
+	ret = 1;
+
+out:
+	if (pr)
+		blkid_free_probe(pr);
+	if (ret == -1)
+		fprintf(stderr,
+			"probe of %s failed, cannot detect "
+			  "existing filesystem.\n", device);
+	return ret;
+}
+
+/*
+ * Check if a device is suitable for btrfs
+ * returns:
+ *  1: something is wrong, an error is printed
+ *  0: all is fine
+ */
+int test_dev_for_mkfs(const char *file, int force_overwrite)
+{
+	int ret, fd;
+	struct stat st;
+
+	ret = is_swap_device(file);
+	if (ret < 0) {
+		error("checking status of %s: %s", file, strerror(-ret));
+		return 1;
+	}
+	if (ret == 1) {
+		error("%s is a swap device", file);
+		return 1;
+	}
+	if (!force_overwrite) {
+		if (check_overwrite(file)) {
+			error("use the -f option to force overwrite of %s",
+					file);
+			return 1;
+		}
+	}
+	ret = check_mounted(file);
+	if (ret < 0) {
+		error("cannot check mount status of %s: %s", file,
+				strerror(-ret));
+		return 1;
+	}
+	if (ret == 1) {
+		error("%s is mounted", file);
+		return 1;
+	}
+	/* check if the device is busy */
+	fd = open(file, O_RDWR|O_EXCL);
+	if (fd < 0) {
+		error("unable to open %s: %s", file, strerror(errno));
+		return 1;
+	}
+	if (fstat(fd, &st)) {
+		error("unable to stat %s: %s", file, strerror(errno));
+		close(fd);
+		return 1;
+	}
+	if (!S_ISBLK(st.st_mode)) {
+		error("%s is not a block device", file);
+		close(fd);
+		return 1;
+	}
+	close(fd);
+	return 0;
+}
+
+int is_vol_small(const char *file)
+{
+	int fd = -1;
+	int e;
+	struct stat st;
+	u64 size;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0)
+		return -errno;
+	if (fstat(fd, &st) < 0) {
+		e = -errno;
+		close(fd);
+		return e;
+	}
+	size = btrfs_device_size(fd, &st);
+	if (size == 0) {
+		close(fd);
+		return -1;
+	}
+	if (size < BTRFS_MKFS_SMALL_VOLUME_SIZE) {
+		close(fd);
+		return 1;
+	} else {
+		close(fd);
+		return 0;
+	}
+}
+
+int test_minimum_size(const char *file, u32 nodesize)
+{
+	int fd;
+	struct stat statbuf;
+
+	fd = open(file, O_RDONLY);
+	if (fd < 0)
+		return -errno;
+	if (stat(file, &statbuf) < 0) {
+		close(fd);
+		return -errno;
+	}
+	if (btrfs_device_size(fd, &statbuf) < btrfs_min_dev_size(nodesize)) {
+		close(fd);
+		return 1;
+	}
+	close(fd);
+	return 0;
+}
+
+