diff --git a/props.c b/props.c index 12fdc524..4d0aeeab 100644 --- a/props.c +++ b/props.c @@ -16,6 +16,8 @@ #include #include +#include +#include #include #include @@ -24,6 +26,10 @@ #include "utils.h" #include "props.h" +#define XATTR_BTRFS_PREFIX "btrfs." +#define XATTR_BTRFS_PREFIX_LEN (sizeof(XATTR_BTRFS_PREFIX) - 1) + + static int prop_read_only(enum prop_object_type type, const char *object, const char *name, @@ -102,10 +108,82 @@ static int prop_label(enum prop_object_type type, return ret; } +static int prop_compression(enum prop_object_type type, + const char *object, + const char *name, + const char *value) +{ + int ret; + ssize_t sret; + int fd = -1; + DIR *dirstream = NULL; + char *buf = NULL; + char *xattr_name = NULL; + + fd = open_file_or_dir(object, &dirstream); + if (fd == -1) { + ret = -errno; + fprintf(stderr, "ERROR: open %s failed. %s\n", + object, strerror(-ret)); + goto out; + } + + xattr_name = malloc(XATTR_BTRFS_PREFIX_LEN + strlen(name)); + if (!xattr_name) { + ret = -ENOMEM; + goto out; + } + memcpy(xattr_name, XATTR_BTRFS_PREFIX, XATTR_BTRFS_PREFIX_LEN); + memcpy(xattr_name + XATTR_BTRFS_PREFIX_LEN, name, strlen(name)); + + if (value) + sret = fsetxattr(fd, xattr_name, value, strlen(value), 0); + else + sret = fgetxattr(fd, xattr_name, NULL, 0); + if (sret < 0) { + ret = -errno; + if (ret != -ENODATA) + fprintf(stderr, + "ERROR: failed to %s compression for %s. %s\n", + value ? "set" : "get", object, strerror(-ret)); + goto out; + } + if (!value) { + size_t len = sret; + + buf = malloc(len); + if (!buf) { + ret = -ENOMEM; + goto out; + } + sret = fgetxattr(fd, xattr_name, buf, len); + if (sret < 0) { + ret = -errno; + fprintf(stderr, + "ERROR: failed to get compression for %s. %s\n", + object, strerror(-ret)); + goto out; + } + fprintf(stdout, "compression=%.*s\n", (int)len, buf); + } + + ret = 0; +out: + free(xattr_name); + free(buf); + if (fd >= 0) + close_file_or_dir(fd, dirstream); + + return ret; +} + + const struct prop_handler prop_handlers[] = { {"ro", "Set/get read-only flag of subvolume.", 0, prop_object_subvol, prop_read_only}, {"label", "Set/get label of device.", 0, prop_object_dev | prop_object_root, prop_label}, + {"compression", "Set/get compression for a file or directory", 0, + prop_object_inode, prop_compression}, {0, 0, 0, 0, 0} };