]> wimlib.net Git - wimlib/blobdiff - src/mount.c
Implement user-specified staging directory
[wimlib] / src / mount.c
index 44857c8c8783972efd1de4f7626fe239504e021f..b0d256e2796eff72ea8e02f0ee056fef144ef07a 100644 (file)
@@ -65,9 +65,6 @@ struct wimfs_context {
        /* The WIMStruct for the mounted WIM. */
        WIMStruct *wim;
 
-       /* Working directory when `imagex mount' is run. */
-       char *working_directory;
-
        /* Name of the staging directory for a read-write mount.  Whenever a new file is
         * created, it is done so in the staging directory.  Furthermore, whenever a
         * file in the WIM is modified, it is extracted to the staging directory.  If
@@ -115,6 +112,11 @@ static inline WIMStruct *wimfs_get_WIMStruct()
        return wimfs_get_context()->wim;
 }
 
+static inline bool wimfs_ctx_readonly(const struct wimfs_context *ctx)
+{
+       return (ctx->mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) == 0;
+}
+
 static inline int get_lookup_flags(const struct wimfs_context *ctx)
 {
        if (ctx->mount_flags & WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)
@@ -136,13 +138,15 @@ static inline int flags_writable(int open_flags)
  * @stream_id: ID of the stream we're opening
  * @lte:       Lookup table entry for the stream (may be NULL)
  * @fd_ret:    Return the allocated file descriptor if successful.
+ * @readonly:  True if this is a read-only mount.
  *
  * Return 0 iff successful or error code if unsuccessful.
  */
 static int alloc_wimlib_fd(struct inode *inode,
                           u32 stream_id,
                           struct lookup_table_entry *lte,
-                          struct wimlib_fd **fd_ret)
+                          struct wimlib_fd **fd_ret,
+                          bool readonly)
 {
        static const u16 fds_per_alloc = 8;
        static const u16 max_fds = 0xffff;
@@ -192,8 +196,8 @@ static int alloc_wimlib_fd(struct inode *inode,
                        *fd_ret        = fd;
                        inode->fds[i]  = fd;
                        inode->num_opened_fds++;
-                       if (lte)
-                               atomic_inc(&lte->num_opened_fds);
+                       if (lte && !readonly)
+                               lte->num_opened_fds++;
                        DEBUG("Allocated fd (idx = %u)", fd->idx);
                        ret = 0;
                        break;
@@ -500,37 +504,70 @@ out_delete_staging_file:
  * Creates a randomly named staging directory and saves its name in the
  * filesystem context structure.
  */
-static int make_staging_dir(struct wimfs_context *ctx)
+static int make_staging_dir(struct wimfs_context *ctx,
+                           const char *user_prefix)
 {
-       /* XXX Give the user an option of where to stage files */
-
-       static const char prefix[] = "wimlib-staging-";
-       static const size_t prefix_len = sizeof(prefix) - 1;
        static const size_t random_suffix_len = 10;
+       static const char *common_suffix = ".staging";
+       static const size_t common_suffix_len = 8;
 
-       size_t pwd_len = strlen(ctx->working_directory);
+       char *staging_dir_name = NULL;
+       size_t staging_dir_name_len;
+       size_t prefix_len;
+       const char *wim_basename;
+       char *real_user_prefix = NULL;
+       int ret;
 
-       ctx->staging_dir_name_len = pwd_len + 1 + prefix_len + random_suffix_len;
+       if (user_prefix) {
+               real_user_prefix = realpath(user_prefix, NULL);
+               if (!real_user_prefix) {
+                       ERROR_WITH_ERRNO("Could not resolve `%s'",
+                                        real_user_prefix);
+                       ret = WIMLIB_ERR_NOTDIR;
+                       goto out;
+               }
+               wim_basename = path_basename(ctx->wim->filename);
+               prefix_len = strlen(real_user_prefix) + 1 + strlen(wim_basename);
+       } else {
+               prefix_len = strlen(ctx->wim->filename);
+       }
 
-       ctx->staging_dir_name = MALLOC(ctx->staging_dir_name_len + 1);
-       if (!ctx->staging_dir_name)
-               return WIMLIB_ERR_NOMEM;
+       staging_dir_name_len = prefix_len + common_suffix_len + random_suffix_len;
+
+       staging_dir_name = MALLOC(staging_dir_name_len + 1);
+       if (!staging_dir_name) {
+               ret = WIMLIB_ERR_NOMEM;
+               goto out;
+       }
+
+       if (real_user_prefix)
+               sprintf(staging_dir_name, "%s/%s", real_user_prefix, wim_basename);
+       else
+               strcpy(staging_dir_name, ctx->wim->filename);
+
+       strcat(staging_dir_name, common_suffix);
+
+       randomize_char_array_with_alnum(staging_dir_name + prefix_len + common_suffix_len,
+                                       random_suffix_len);
 
-       memcpy(ctx->staging_dir_name, ctx->working_directory, pwd_len);
-       ctx->staging_dir_name[pwd_len] = '/';
-       memcpy(ctx->staging_dir_name + pwd_len + 1, prefix, prefix_len);
-       randomize_char_array_with_alnum(ctx->staging_dir_name + pwd_len +
-                                       1 + prefix_len, random_suffix_len);
-       ctx->staging_dir_name[ctx->staging_dir_name_len] = '\0';
+       staging_dir_name[staging_dir_name_len] = '\0';
 
-       if (mkdir(ctx->staging_dir_name, 0700) != 0) {
+       if (mkdir(staging_dir_name, 0700) != 0) {
                ERROR_WITH_ERRNO("Failed to create temporary directory `%s'",
-                                ctx->staging_dir_name);
-               FREE(ctx->staging_dir_name);
-               ctx->staging_dir_name = NULL;
-               return WIMLIB_ERR_MKDIR;
+                                staging_dir_name);
+               ret = WIMLIB_ERR_MKDIR;
+       } else {
+               ret = 0;
        }
-       return 0;
+out:
+       FREE(real_user_prefix);
+       if (ret == 0) {
+               ctx->staging_dir_name = staging_dir_name;
+               ctx->staging_dir_name_len = staging_dir_name_len;
+       } else {
+               FREE(staging_dir_name);
+       }
+       return ret;
 }
 
 static int remove_file_or_directory(const char *fpath, const struct stat *sb,
@@ -866,7 +903,7 @@ static int inode_close_fds(struct inode *inode)
 }
 
 /* Overwrites the WIM file, with changes saved. */
-static int rebuild_wim(struct wimfs_context *ctx, bool check_integrity)
+static int rebuild_wim(struct wimfs_context *ctx, int write_flags)
 {
        int ret;
        struct lookup_table_entry *lte, *tmp;
@@ -889,7 +926,7 @@ static int rebuild_wim(struct wimfs_context *ctx, bool check_integrity)
 
        xml_update_image_info(w, w->current_image);
 
-       ret = wimlib_overwrite(w, check_integrity);
+       ret = wimlib_overwrite(w, write_flags, 0, NULL);
        if (ret != 0) {
                ERROR("Failed to commit changes");
                return ret;
@@ -916,6 +953,7 @@ static void wimfs_destroy(void *p)
        char status;
        char *mailbox;
        struct wimfs_context *ctx = wimfs_get_context();
+       int write_flags;
 
        if (open_message_queues(ctx, true))
                return;
@@ -946,13 +984,11 @@ static void wimfs_destroy(void *p)
        status = 0;
        if (ctx->mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
                if (commit) {
-                       ret = chdir(ctx->working_directory);
-                       if (ret == 0) {
-                               status = rebuild_wim(ctx, (check_integrity != 0));
-                       } else {
-                               ERROR_WITH_ERRNO("chdir()");
-                               status = WIMLIB_ERR_NOTDIR;
-                       }
+                       if (check_integrity)
+                               write_flags = WIMLIB_WRITE_FLAG_CHECK_INTEGRITY;
+                       else
+                               write_flags = 0;
+                       status = rebuild_wim(ctx, write_flags);
                }
                ret = delete_staging_dir(ctx);
                if (ret != 0) {
@@ -1056,7 +1092,8 @@ static int wimfs_getxattr(const char *path, const char *name, char *value,
        if (res_size > size)
                return -ERANGE;
 
-       ret = read_full_wim_resource(lte, (u8*)value);
+       ret = read_full_wim_resource(lte, (u8*)value,
+                                    WIMLIB_RESOURCE_FLAG_MULTITHREADED);
        if (ret != 0)
                return -EIO;
 
@@ -1268,7 +1305,8 @@ static int wimfs_open(const char *path, struct fuse_file_info *fi)
                        return ret;
        }
 
-       ret = alloc_wimlib_fd(inode, stream_id, lte, &fd);
+       ret = alloc_wimlib_fd(inode, stream_id, lte, &fd,
+                             wimfs_ctx_readonly(ctx));
        if (ret != 0)
                return ret;
 
@@ -1289,14 +1327,15 @@ static int wimfs_opendir(const char *path, struct fuse_file_info *fi)
        struct inode *inode;
        int ret;
        struct wimlib_fd *fd = NULL;
-       WIMStruct *w = wimfs_get_WIMStruct();
+       struct wimfs_context *ctx = wimfs_get_context();
+       WIMStruct *w = ctx->wim;
 
        inode = wim_pathname_to_inode(w, path);
        if (!inode)
                return -ENOENT;
        if (!inode_is_directory(inode))
                return -ENOTDIR;
-       ret = alloc_wimlib_fd(inode, 0, NULL, &fd);
+       ret = alloc_wimlib_fd(inode, 0, NULL, &fd, wimfs_ctx_readonly(ctx));
        fi->fh = (uintptr_t)fd;
        return ret;
 }
@@ -1334,6 +1373,8 @@ static int wimfs_read(const char *path, char *buf, size_t size,
        } else {
                /* Read from WIM */
 
+               wimlib_assert(fd->f_lte->resource_location == RESOURCE_IN_WIM);
+
                u64 res_size = wim_resource_size(fd->f_lte);
 
                if (offset > res_size)
@@ -1342,7 +1383,8 @@ static int wimfs_read(const char *path, char *buf, size_t size,
                size = min(size, res_size - offset);
 
                if (read_wim_resource(fd->f_lte, (u8*)buf,
-                                     size, offset, false) != 0)
+                                     size, offset,
+                                     WIMLIB_RESOURCE_FLAG_MULTITHREADED) != 0)
                        return -EIO;
                return size;
        }
@@ -1396,7 +1438,8 @@ static int wimfs_readlink(const char *path, char *buf, size_t buf_len)
        if (!inode_is_symlink(inode))
                return -EINVAL;
 
-       ret = inode_readlink(inode, buf, buf_len, ctx->wim);
+       ret = inode_readlink(inode, buf, buf_len, ctx->wim,
+                            WIMLIB_RESOURCE_FLAG_MULTITHREADED);
        if (ret > 0)
                ret = 0;
        return ret;
@@ -1828,13 +1871,22 @@ static struct fuse_operations wimfs_operations = {
        .utime       = wimfs_utime,
 #endif
        .write       = wimfs_write,
+
+#if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 8)
+       .flag_nullpath_ok = 1,
+#endif
+#if FUSE_MAJOR_VERSION > 2 || (FUSE_MAJOR_VERSION == 2 && FUSE_MINOR_VERSION >= 9)
+       .flag_nopath = 1,
+       .flag_utime_omit_ok = 1,
+#endif
 };
 
 
-/* Mounts a WIM file. */
-WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
-                          int flags, WIMStruct **additional_swms,
-                          unsigned num_additional_swms)
+/* Mounts an image from a WIM file. */
+WIMLIBAPI int wimlib_mount_image(WIMStruct *wim, int image, const char *dir,
+                                int mount_flags, WIMStruct **additional_swms,
+                                unsigned num_additional_swms,
+                                const char *staging_dir)
 {
        int argc = 0;
        char *argv[16];
@@ -1845,7 +1897,7 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
        struct wimfs_context ctx;
 
        DEBUG("Mount: wim = %p, image = %d, dir = %s, flags = %d, ",
-             wim, image, dir, flags);
+             wim, image, dir, mount_flags);
 
        if (!wim || !dir)
                return WIMLIB_ERR_INVALID_PARAM;
@@ -1854,6 +1906,11 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
        if (ret != 0)
                return ret;
 
+       if ((mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) && (wim->hdr.total_parts != 1)) {
+               ERROR("Cannot mount a split WIM read-write");
+               return WIMLIB_ERR_SPLIT_UNSUPPORTED;
+       }
+
        if (num_additional_swms) {
                ret = new_joined_lookup_table(wim, additional_swms,
                                              num_additional_swms,
@@ -1875,32 +1932,39 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
 
        if (imd->root_dentry->refcnt != 1) {
                ERROR("Cannot mount image that was just exported with "
-                     "wimlib_export()");
+                     "wimlib_export_image()");
+               ret = WIMLIB_ERR_INVALID_PARAM;
+               goto out;
+       }
+
+       if (imd->modified) {
+               ERROR("Cannot mount image that was added "
+                     "with wimlib_add_image()");
                ret = WIMLIB_ERR_INVALID_PARAM;
                goto out;
        }
 
-       if (!(flags & (WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE |
+       if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
+               ret = lock_wim(wim->fp, wim->filename);
+               if (ret != 0)
+                       goto out;
+       }
+
+       if (!(mount_flags & (WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE |
                       WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR |
                       WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS)))
-               flags |= WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR;
+               mount_flags |= WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR;
 
 
        DEBUG("Initializing struct wimfs_context");
        init_wimfs_context(&ctx);
-
-       DEBUG("Getting current directory");
-       ctx.working_directory = getcwd(NULL, 0);
-       if (!ctx.working_directory) {
-               ERROR_WITH_ERRNO("Could not determine current directory");
-               ret = WIMLIB_ERR_NOTDIR;
-               goto out;
-       }
+       ctx.wim = wim;
+       ctx.mount_flags = mount_flags;
 
        DEBUG("Unlinking message queues in case they already exist");
        ret = set_message_queue_names(&ctx, dir);
        if (ret != 0)
-               goto out_free_working_directory;
+               goto out;
        unlink_message_queues(&ctx);
 
        DEBUG("Preparing arguments to fuse_main()");
@@ -1913,10 +1977,10 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
        argv[argc++] = dir_copy;
 
        /* disable multi-threaded operation for read-write mounts */
-       if (flags & WIMLIB_MOUNT_FLAG_READWRITE)
+       if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)
                argv[argc++] = "-s";
 
-       if (flags & WIMLIB_MOUNT_FLAG_DEBUG)
+       if (mount_flags & WIMLIB_MOUNT_FLAG_DEBUG)
                argv[argc++] = "-d";
 
        /*
@@ -1928,9 +1992,9 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
        char optstring[256] = "use_ino,subtype=wimfs,attr_timeout=0";
        argv[argc++] = "-o";
        argv[argc++] = optstring;
-       if ((flags & WIMLIB_MOUNT_FLAG_READWRITE)) {
+       if ((mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)) {
                /* Read-write mount.  Make the staging directory */
-               ret = make_staging_dir(&ctx);
+               ret = make_staging_dir(&ctx, staging_dir);
                if (ret != 0)
                        goto out_free_dir_copy;
        } else {
@@ -1953,8 +2017,10 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
 #endif
 
        /* Mark dentry tree as modified if read-write mount. */
-       if (flags & WIMLIB_MOUNT_FLAG_READWRITE)
+       if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
                imd->modified = true;
+               imd->has_been_mounted_rw = true;
+       }
 
        /* Resolve all the lookup table entries of the dentry tree */
        DEBUG("Resolving lookup table entries");
@@ -1964,9 +2030,6 @@ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir,
        ctx.next_ino = assign_inode_numbers(&imd->inode_list);
        DEBUG("(next_ino = %"PRIu64")", ctx.next_ino);
 
-       /* Finish initializing the filesystem context. */
-       ctx.wim = wim;
-       ctx.mount_flags = flags;
 
        DEBUG("Calling fuse_main()");
 
@@ -1979,9 +2042,6 @@ out_free_dir_copy:
        FREE(dir_copy);
 out_free_message_queue_names:
        free_message_queue_names(&ctx);
-out_free_working_directory:
-       FREE(ctx.working_directory);
-       ctx.working_directory = NULL;
 out:
        if (num_additional_swms) {
                free_lookup_table(wim->lookup_table);
@@ -1993,9 +2053,10 @@ out:
 
 /*
  * Unmounts the WIM file that was previously mounted on @dir by using
- * wimlib_mount().
+ * wimlib_mount_image().
  */
-WIMLIBAPI int wimlib_unmount(const char *dir, int flags)
+WIMLIBAPI int wimlib_unmount_image(const char *dir, int unmount_flags,
+                                  wimlib_progress_func_t progress_func)
 {
        pid_t pid;
        int status;
@@ -2021,8 +2082,8 @@ WIMLIBAPI int wimlib_unmount(const char *dir, int flags)
 
        /* Send a message to the filesystem daemon saying whether to commit or
         * not. */
-       msg[0] = (flags & WIMLIB_UNMOUNT_FLAG_COMMIT) ? 1 : 0;
-       msg[1] = (flags & WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY) ? 1 : 0;
+       msg[0] = (unmount_flags & WIMLIB_UNMOUNT_FLAG_COMMIT) ? 1 : 0;
+       msg[1] = (unmount_flags & WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY) ? 1 : 0;
 
        DEBUG("Sending message: %scommit, %scheck",
                        (msg[0] ? "" : "don't "),
@@ -2172,14 +2233,16 @@ static inline int mount_unsupported_error()
        return WIMLIB_ERR_UNSUPPORTED;
 }
 
-WIMLIBAPI int wimlib_unmount(const char *dir, int flags)
+WIMLIBAPI int wimlib_unmount_image(const char *dir, int unmount_flags,
+                                  wimlib_progress_func_t progress_func)
 {
        return mount_unsupported_error();
 }
 
-WIMLIBAPI int wimlib_mount(WIMStruct *wim_p, int image, const char *dir,
-                          int flags, WIMStruct **additional_swms,
-                          unsigned num_additional_swms)
+WIMLIBAPI int wimlib_mount_image(WIMStruct *wim_p, int image, const char *dir,
+                                int mount_flags, WIMStruct **additional_swms,
+                                unsigned num_additional_swms,
+                                const char *staging_dir)
 {
        return mount_unsupported_error();
 }