diff options
Diffstat (limited to 'props.c')
| -rw-r--r-- | props.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/props.c b/props.c new file mode 100644 index 00000000..a7e3e96b --- /dev/null +++ b/props.c @@ -0,0 +1,194 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <sys/xattr.h> +#include <fcntl.h> +#include <unistd.h> + +#include "ctree.h" +#include "commands.h" +#include "utils.h" +#include "props.h" + +#define XATTR_BTRFS_PREFIX "btrfs." +#define XATTR_BTRFS_PREFIX_LEN (sizeof(XATTR_BTRFS_PREFIX) - 1) + +/* + * Defined as synonyms in attr/xattr.h + */ +#ifndef ENOATTR +#define ENOATTR ENODATA +#endif + +static int prop_read_only(enum prop_object_type type, + const char *object, + const char *name, + const char *value) +{ + int ret = 0; + int fd = -1; + u64 flags = 0; + + fd = open(object, O_RDONLY); + if (fd < 0) { + ret = -errno; + error("failed to open %s: %s", object, strerror(-ret)); + goto out; + } + + ret = ioctl(fd, BTRFS_IOC_SUBVOL_GETFLAGS, &flags); + if (ret < 0) { + ret = -errno; + error("failed to get flags for %s: %s", object, + strerror(-ret)); + goto out; + } + + if (!value) { + if (flags & BTRFS_SUBVOL_RDONLY) + fprintf(stdout, "ro=true\n"); + else + fprintf(stdout, "ro=false\n"); + ret = 0; + goto out; + } + + if (!strcmp(value, "true")) { + flags |= BTRFS_SUBVOL_RDONLY; + } else if (!strcmp(value, "false")) { + flags = flags & ~BTRFS_SUBVOL_RDONLY; + } else { + ret = -EINVAL; + error("invalid value for property: %s", value); + goto out; + } + + ret = ioctl(fd, BTRFS_IOC_SUBVOL_SETFLAGS, &flags); + if (ret < 0) { + ret = -errno; + error("failed to set flags for %s: %s", object, + strerror(-ret)); + goto out; + } + +out: + if (fd != -1) + close(fd); + return ret; +} + +static int prop_label(enum prop_object_type type, + const char *object, + const char *name, + const char *value) +{ + int ret; + + if (value) { + ret = set_label((char *) object, (char *) value); + } else { + char label[BTRFS_LABEL_SIZE]; + + ret = get_label((char *) object, label); + if (!ret) + fprintf(stdout, "label=%s\n", label); + } + + 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; + int open_flags = value ? O_RDWR : O_RDONLY; + + fd = open_file_or_dir3(object, &dirstream, open_flags); + if (fd == -1) { + ret = -errno; + error("failed to open %s: %s", object, strerror(-ret)); + goto out; + } + + xattr_name = malloc(XATTR_BTRFS_PREFIX_LEN + strlen(name) + 1); + 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)); + xattr_name[XATTR_BTRFS_PREFIX_LEN + strlen(name)] = '\0'; + + 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 != -ENOATTR) + error("failed to %s compression for %s: %s", + value ? "set" : "get", object, strerror(-ret)); + else + ret = 0; + 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; + error("failed to get compression for %s: %s", + 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}, + {NULL, NULL, 0, 0, NULL} +}; |