]> wimlib.net Git - wimlib/blobdiff - src/unix_apply.c
unix_apply.c: separate creation, data extraction, and metadata passes
[wimlib] / src / unix_apply.c
index b17bd35101c39c48a078fea47b57a2bdcfc1e6fa..150f592d707c5a46267ec6315c22f0258222545b 100644 (file)
@@ -202,83 +202,40 @@ should_extract_as_directory(const struct wim_inode *inode)
                !inode_is_symlink(inode);
 }
 
-/* Sets the timestamps on a file being extracted.
- *
- * Either @fd or @path must be specified (not -1 and not NULL, respectively).
- */
+/* Sets the timestamps on a file being extracted. */
 static int
-unix_set_timestamps(int fd, const char *path, u64 atime, u64 mtime)
+unix_set_timestamps(const char *path, u64 atime, u64 mtime)
 {
+#ifdef HAVE_UTIMENSAT
        {
                struct timespec times[2];
 
                times[0] = wim_timestamp_to_timespec(atime);
                times[1] = wim_timestamp_to_timespec(mtime);
 
-               errno = ENOSYS;
-#ifdef HAVE_FUTIMENS
-               if (fd >= 0 && !futimens(fd, times))
-                       return 0;
-#endif
-#ifdef HAVE_UTIMENSAT
-               if (fd < 0 && !utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW))
+               if (utimensat(AT_FDCWD, path, times, AT_SYMLINK_NOFOLLOW) == 0)
                        return 0;
-#endif
                if (errno != ENOSYS)
-                       return WIMLIB_ERR_SET_TIMESTAMPS;
+                       return -1;
        }
+#endif
        {
                struct timeval times[2];
 
                times[0] = wim_timestamp_to_timeval(atime);
                times[1] = wim_timestamp_to_timeval(mtime);
 
-               if (fd >= 0 && !futimes(fd, times))
-                       return 0;
-               if (fd < 0 && !lutimes(path, times))
-                       return 0;
-               return WIMLIB_ERR_SET_TIMESTAMPS;
+               return lutimes(path, times);
        }
 }
 
+/* Set metadata on an extracted file. */
 static int
-unix_set_owner_and_group(int fd, const char *path, uid_t uid, gid_t gid)
-{
-       if (fd >= 0 && !fchown(fd, uid, gid))
-               return 0;
-       if (fd < 0 && !lchown(path, uid, gid))
-               return 0;
-       return WIMLIB_ERR_SET_SECURITY;
-}
-
-static int
-unix_set_mode(int fd, const char *path, mode_t mode)
-{
-       if (fd >= 0 && !fchmod(fd, mode))
-               return 0;
-       if (fd < 0 && !chmod(path, mode))
-               return 0;
-       return WIMLIB_ERR_SET_SECURITY;
-}
-
-/*
- * Set metadata on an extracted file.
- *
- * @fd is an open file descriptor to the extracted file, or -1.  @path is the
- * path to the extracted file, or NULL.  If valid, this function uses @fd.
- * Otherwise, if valid, it uses @path.  Otherwise, it calculates the path to one
- * alias of the extracted file and uses it.
- */
-static int
-unix_set_metadata(int fd, const struct wim_inode *inode,
-                 const char *path, struct unix_apply_ctx *ctx)
+unix_set_metadata(const struct wim_inode *inode, struct unix_apply_ctx *ctx)
 {
-       int ret;
+       const char *path = unix_build_inode_extraction_path(inode, ctx);
        struct wimlib_unix_data unix_data;
 
-       if (fd < 0 && !path)
-               path = unix_build_inode_extraction_path(inode, ctx);
-
        if ((ctx->common.extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA)
            && inode_get_unix_data(inode, &unix_data))
        {
@@ -286,75 +243,61 @@ unix_set_metadata(int fd, const struct wim_inode *inode,
                u32 gid = unix_data.gid;
                u32 mode = unix_data.mode;
 
-               ret = unix_set_owner_and_group(fd, path, uid, gid);
-               if (ret) {
-                       if (!path)
-                               path = unix_build_inode_extraction_path(inode, ctx);
+               if (lchown(path, uid, gid) != 0) {
                        if (ctx->common.extract_flags &
                            WIMLIB_EXTRACT_FLAG_STRICT_ACLS)
                        {
                                ERROR_WITH_ERRNO("Can't set uid=%"PRIu32" and "
                                                 "gid=%"PRIu32" on \"%s\"",
                                                 uid, gid, path);
-                               return ret;
-                       } else {
-                               WARNING_WITH_ERRNO("Can't set uid=%"PRIu32" and "
-                                                  "gid=%"PRIu32" on \"%s\"",
-                                                  uid, gid, path);
+                               return WIMLIB_ERR_SET_SECURITY;
                        }
+                       WARNING_WITH_ERRNO("Can't set uid=%"PRIu32" and "
+                                          "gid=%"PRIu32" on \"%s\"",
+                                          uid, gid, path);
                }
 
-               ret = 0;
-               if (!inode_is_symlink(inode))
-                       ret = unix_set_mode(fd, path, mode);
-               if (ret) {
-                       if (!path)
-                               path = unix_build_inode_extraction_path(inode, ctx);
+               if (!inode_is_symlink(inode) && chmod(path, mode) != 0) {
                        if (ctx->common.extract_flags &
                            WIMLIB_EXTRACT_FLAG_STRICT_ACLS)
                        {
                                ERROR_WITH_ERRNO("Can't set mode=0%"PRIo32" "
                                                 "on \"%s\"", mode, path);
-                               return ret;
-                       } else {
-                               WARNING_WITH_ERRNO("Can't set mode=0%"PRIo32" "
-                                                  "on \"%s\"", mode, path);
+                               return WIMLIB_ERR_SET_SECURITY;
                        }
+                       WARNING_WITH_ERRNO("Can't set mode=0%"PRIo32" "
+                                          "on \"%s\"", mode, path);
                }
        }
 
-       ret = unix_set_timestamps(fd, path,
-                                 inode->i_last_access_time,
-                                 inode->i_last_write_time);
-       if (ret) {
-               if (!path)
-                       path = unix_build_inode_extraction_path(inode, ctx);
+       if (unix_set_timestamps(path, inode->i_last_access_time,
+                               inode->i_last_write_time) != 0)
+       {
                if (ctx->common.extract_flags &
                    WIMLIB_EXTRACT_FLAG_STRICT_TIMESTAMPS)
                {
                        ERROR_WITH_ERRNO("Can't set timestamps on \"%s\"", path);
-                       return ret;
-               } else {
-                       WARNING_WITH_ERRNO("Can't set timestamps on \"%s\"", path);
+                       return WIMLIB_ERR_SET_TIMESTAMPS;
                }
+               WARNING_WITH_ERRNO("Can't set timestamps on \"%s\"", path);
        }
        return 0;
 }
 
-/* Extract all needed aliases of the @inode, where one alias, corresponding to
- * @first_dentry, has already been extracted to @first_path.  */
+/*
+ * Extract all needed aliases of the specified @inode, where the first alias has
+ * already been extracted to @first_path.
+ */
 static int
 unix_create_hardlinks(const struct wim_inode *inode,
-                     const struct wim_dentry *first_dentry,
                      const char *first_path, struct unix_apply_ctx *ctx)
 {
        const struct wim_dentry *dentry;
        const char *newpath;
 
        inode_for_each_extraction_alias(dentry, inode) {
-               if (dentry == first_dentry)
+               if (dentry == inode_first_extraction_dentry(inode))
                        continue;
-
                newpath = unix_build_extraction_path(dentry, ctx);
        retry_link:
                if (link(first_path, newpath)) {
@@ -369,18 +312,13 @@ unix_create_hardlinks(const struct wim_inode *inode,
        return 0;
 }
 
-/* If @dentry represents a directory, create it.  */
 static int
-unix_create_if_directory(const struct wim_dentry *dentry,
-                        struct unix_apply_ctx *ctx)
+unix_create_directory(const struct wim_dentry *dentry,
+                     struct unix_apply_ctx *ctx)
 {
-       const char *path;
+       const char *path = unix_build_extraction_path(dentry, ctx);
        struct stat stbuf;
 
-       if (!should_extract_as_directory(dentry->d_inode))
-               return 0;
-
-       path = unix_build_extraction_path(dentry, ctx);
        if (mkdir(path, 0755) &&
            /* It's okay if the path already exists, as long as it's a
             * directory.  */
@@ -390,38 +328,21 @@ unix_create_if_directory(const struct wim_dentry *dentry,
                return WIMLIB_ERR_MKDIR;
        }
 
-       return report_file_created(&ctx->common);
+       return 0;
 }
 
-/* If @dentry represents an empty regular file or a special file, create it, set
- * its metadata, and create any needed hard links.  */
 static int
-unix_extract_if_empty_file(const struct wim_dentry *dentry,
-                          struct unix_apply_ctx *ctx)
+unix_create_nondirectory(const struct wim_inode *inode,
+                        struct unix_apply_ctx *ctx)
 {
-       const struct wim_inode *inode;
+       const char *path = unix_build_inode_extraction_path(inode, ctx);
        struct wimlib_unix_data unix_data;
-       const char *path;
-       int ret;
-
-       inode = dentry->d_inode;
-
-       /* Extract all aliases only when the "first" comes up.  */
-       if (dentry != inode_first_extraction_dentry(inode))
-               return 0;
-
-       /* Is this a directory, a symbolic link, or any type of nonempty file?
-        */
-       if (should_extract_as_directory(inode) || inode_is_symlink(inode) ||
-           inode_get_blob_for_unnamed_data_stream_resolved(inode))
-               return 0;
 
        /* Recognize special files in UNIX_DATA mode  */
        if ((ctx->common.extract_flags & WIMLIB_EXTRACT_FLAG_UNIX_DATA) &&
            inode_get_unix_data(inode, &unix_data) &&
            !S_ISREG(unix_data.mode))
        {
-               path = unix_build_extraction_path(dentry, ctx);
        retry_mknod:
                if (mknod(path, unix_data.mode, unix_data.rdev)) {
                        if (errno == EPERM) {
@@ -436,13 +357,9 @@ unix_extract_if_empty_file(const struct wim_dentry *dentry,
                                         path);
                        return WIMLIB_ERR_MKNOD;
                }
-               /* On special files, we can set timestamps immediately because
-                * we don't need to write any data to them.  */
-               ret = unix_set_metadata(-1, inode, path, ctx);
        } else {
                int fd;
 
-               path = unix_build_extraction_path(dentry, ctx);
        retry_create:
                fd = open(path, O_EXCL | O_CREAT | O_WRONLY | O_NOFOLLOW, 0644);
                if (fd < 0) {
@@ -451,38 +368,43 @@ unix_extract_if_empty_file(const struct wim_dentry *dentry,
                        ERROR_WITH_ERRNO("Can't create regular file \"%s\"", path);
                        return WIMLIB_ERR_OPEN;
                }
-               /* On empty files, we can set timestamps immediately because we
-                * don't need to write any data to them.  */
-               ret = unix_set_metadata(fd, inode, path, ctx);
-               if (close(fd) && !ret) {
+               if (close(fd)) {
                        ERROR_WITH_ERRNO("Error closing \"%s\"", path);
-                       ret = WIMLIB_ERR_WRITE;
+                       return WIMLIB_ERR_WRITE;
                }
        }
-       if (ret)
-               return ret;
-
-       ret = unix_create_hardlinks(inode, dentry, path, ctx);
-       if (ret)
-               return ret;
 
-       return report_file_created(&ctx->common);
+       return unix_create_hardlinks(inode, path, ctx);
 }
 
+/* Create all files (and directories) except for symlinks. */
 static int
-unix_create_dirs_and_empty_files(const struct list_head *dentry_list,
-                                struct unix_apply_ctx *ctx)
+unix_create_file_structure(const struct list_head *dentry_list,
+                          struct unix_apply_ctx *ctx)
 {
        const struct wim_dentry *dentry;
+       const struct wim_inode *inode;
        int ret;
 
        list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
-               ret = unix_create_if_directory(dentry, ctx);
+               inode = dentry->d_inode;
+               if (!should_extract_as_directory(inode))
+                       continue;
+               ret = unix_create_directory(dentry, ctx);
+               if (!ret)
+                       ret = report_file_created(&ctx->common);
                if (ret)
                        return ret;
        }
        list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
-               ret = unix_extract_if_empty_file(dentry, ctx);
+               inode = dentry->d_inode;
+               if (should_extract_as_directory(inode) ||
+                   inode_is_symlink(inode) ||
+                   dentry != inode_first_extraction_dentry(inode))
+                       continue;
+               ret = unix_create_nondirectory(inode, ctx);
+               if (!ret)
+                       ret = report_file_created(&ctx->common);
                if (ret)
                        return ret;
        }
@@ -490,27 +412,21 @@ unix_create_dirs_and_empty_files(const struct list_head *dentry_list,
 }
 
 static void
-unix_count_dentries(const struct list_head *dentry_list,
-                   u64 *dir_count_ret, u64 *empty_file_count_ret)
+unix_count_inodes(const struct list_head *dentry_list,
+                 u64 *full_count, u64 *symlink_count)
 {
        const struct wim_dentry *dentry;
-       u64 dir_count = 0;
-       u64 empty_file_count = 0;
 
-       list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
-
-               const struct wim_inode *inode = dentry->d_inode;
+       *full_count = 0;
+       *symlink_count = 0;
 
-               if (should_extract_as_directory(inode))
-                       dir_count++;
-               else if ((dentry == inode_first_extraction_dentry(inode)) &&
-                        !inode_is_symlink(inode) &&
-                        !inode_get_blob_for_unnamed_data_stream_resolved(inode))
-                       empty_file_count++;
+       list_for_each_entry(dentry, dentry_list, d_extraction_list_node) {
+               if (dentry != inode_first_extraction_dentry(dentry->d_inode))
+                       continue;
+               ++*full_count;
+               if (inode_is_symlink(dentry->d_inode))
+                       ++*symlink_count;
        }
-
-       *dir_count_ret = dir_count;
-       *empty_file_count_ret = empty_file_count;
 }
 
 static int
@@ -558,8 +474,7 @@ unix_begin_extract_blob_instance(const struct blob_descriptor *blob,
                                 const struct wim_inode_stream *strm,
                                 struct unix_apply_ctx *ctx)
 {
-       const struct wim_dentry *first_dentry;
-       const char *first_path;
+       const char *path = unix_build_inode_extraction_path(inode, ctx);
        int fd;
 
        if (unlikely(strm->stream_type == STREAM_TYPE_REPARSE_POINT)) {
@@ -568,7 +483,7 @@ unix_begin_extract_blob_instance(const struct blob_descriptor *blob,
                if (blob->size > REPARSE_DATA_MAX_SIZE) {
                        ERROR_WITH_ERRNO("Reparse data of \"%s\" has size "
                                         "%"PRIu64" bytes (exceeds %u bytes)",
-                                        inode_any_full_path(inode),
+                                        path,
                                         blob->size, REPARSE_DATA_MAX_SIZE);
                        return WIMLIB_ERR_INVALID_REPARSE_DATA;
                }
@@ -583,14 +498,9 @@ unix_begin_extract_blob_instance(const struct blob_descriptor *blob,
        /* This should be ensured by extract_blob_list()  */
        wimlib_assert(ctx->num_open_fds < MAX_OPEN_FILES);
 
-       first_dentry = inode_first_extraction_dentry(inode);
-       first_path = unix_build_extraction_path(first_dentry, ctx);
-retry_create:
-       fd = open(first_path, O_EXCL | O_CREAT | O_WRONLY | O_NOFOLLOW, 0644);
+       fd = open(path, O_WRONLY | O_NOFOLLOW);
        if (fd < 0) {
-               if (errno == EEXIST && !unlink(first_path))
-                       goto retry_create;
-               ERROR_WITH_ERRNO("Can't create regular file \"%s\"", first_path);
+               ERROR_WITH_ERRNO("Can't open regular file \"%s\"", path);
                return WIMLIB_ERR_OPEN;
        }
        if (inode->i_attributes & FILE_ATTRIBUTE_SPARSE_FILE) {
@@ -603,7 +513,7 @@ retry_create:
 #endif
        }
        filedes_init(&ctx->open_fds[ctx->num_open_fds++], fd);
-       return unix_create_hardlinks(inode, first_dentry, first_path, ctx);
+       return 0;
 }
 
 /* Called when starting to read a blob for extraction  */
@@ -699,9 +609,6 @@ unix_end_extract_blob(struct blob_descriptor *blob, int status, void *_ctx)
                                                 "\"%s\"", path);
                                break;
                        }
-                       ret = unix_set_metadata(-1, inode, path, ctx);
-                       if (ret)
-                               break;
                } else {
                        struct filedes *fd = &ctx->open_fds[j];
 
@@ -713,11 +620,6 @@ unix_end_extract_blob(struct blob_descriptor *blob, int status, void *_ctx)
                                break;
                        }
 
-                       /* Set metadata on regular file just before closing.  */
-                       ret = unix_set_metadata(fd->fd, inode, NULL, ctx);
-                       if (ret)
-                               break;
-
                        if (filedes_close(fd)) {
                                ERROR_WITH_ERRNO("Error closing \"%s\"",
                                                 unix_build_inode_extraction_path(inode, ctx));
@@ -731,21 +633,24 @@ unix_end_extract_blob(struct blob_descriptor *blob, int status, void *_ctx)
        return ret;
 }
 
+/* Apply metadata to all extracted files (and directories). */
 static int
-unix_set_dir_metadata(struct list_head *dentry_list, struct unix_apply_ctx *ctx)
+unix_apply_metadata(struct list_head *dentry_list, struct unix_apply_ctx *ctx)
 {
        const struct wim_dentry *dentry;
+       const struct wim_inode *inode;
        int ret;
 
-       list_for_each_entry_reverse(dentry, dentry_list, d_extraction_list_node) {
-               if (should_extract_as_directory(dentry->d_inode)) {
-                       ret = unix_set_metadata(-1, dentry->d_inode, NULL, ctx);
-                       if (ret)
-                               return ret;
+       list_for_each_entry_reverse(dentry, dentry_list, d_extraction_list_node)
+       {
+               inode = dentry->d_inode;
+               if (dentry != inode_first_extraction_dentry(inode))
+                       continue;
+               ret = unix_set_metadata(inode, ctx);
+               if (!ret)
                        ret = report_file_metadata_applied(&ctx->common);
-                       if (ret)
-                               return ret;
-               }
+               if (ret)
+                       return ret;
        }
        return 0;
 }
@@ -756,8 +661,8 @@ unix_extract(struct list_head *dentry_list, struct apply_ctx *_ctx)
        int ret;
        struct unix_apply_ctx *ctx = (struct unix_apply_ctx *)_ctx;
        size_t path_max;
-       u64 dir_count;
-       u64 empty_file_count;
+       u64 full_count;
+       u64 symlink_count;
 
        /* Compute the maximum path length that will be needed, then allocate
         * some path buffers.  */
@@ -775,18 +680,38 @@ unix_extract(struct list_head *dentry_list, struct apply_ctx *_ctx)
                       ctx->common.target, ctx->common.target_nchars);
        }
 
-       /* Extract directories and empty regular files.  Directories are needed
-        * because we can't extract any other files until their directories
-        * exist.  Empty files are needed because they don't have
-        * representatives in the blob list.  */
+       /*
+        * We do the extraction in three phases:
+        *
+        *      1. Create all directories and files except for symlinks
+        *      2. Extract streams
+        *      3. Apply metadata
+        *
+        * In phase (2), the streams which may be extracted include unnamed data
+        * streams (regular file contents), reparse streams (translated to
+        * symlink targets), and extended attribute (xattr) streams.  These may
+        * come up for extraction in any order.  Therefore, at least when xattr
+        * streams are present, all files must be created earlier, in phase (1).
+        *
+        * Symlinks are an exception: they cannot be created until the reparse
+        * stream comes up for extraction.  Currently we hack around this by
+        * caching the xattrs of symlinks in memory until they can be applied
+        * between phases (2) and (3).
+        *
+        * Note that phase (3) must happen after all data all xattr extraction
+        * because it might set the file mode's to readonly (which precludes
+        * setxattr), and it also will set timestamps including the last
+        * modification time (which precludes write).
+        */
 
-       unix_count_dentries(dentry_list, &dir_count, &empty_file_count);
+       unix_count_inodes(dentry_list, &full_count, &symlink_count);
 
-       ret = start_file_structure_phase(&ctx->common, dir_count + empty_file_count);
+       ret = start_file_structure_phase(&ctx->common,
+                                        full_count - symlink_count);
        if (ret)
                goto out;
 
-       ret = unix_create_dirs_and_empty_files(dentry_list, ctx);
+       ret = unix_create_file_structure(dentry_list, ctx);
        if (ret)
                goto out;
 
@@ -806,8 +731,6 @@ unix_extract(struct list_head *dentry_list, struct apply_ctx *_ctx)
                ctx->target_abspath_nchars = strlen(ctx->target_abspath);
        }
 
-       /* Extract nonempty regular files and symbolic links.  */
-
        struct read_blob_callbacks cbs = {
                .begin_blob     = unix_begin_extract_blob,
                .continue_blob  = unix_extract_chunk,
@@ -818,14 +741,11 @@ unix_extract(struct list_head *dentry_list, struct apply_ctx *_ctx)
        if (ret)
                goto out;
 
-
-       /* Set directory metadata.  We do this last so that we get the right
-        * directory timestamps.  */
-       ret = start_file_metadata_phase(&ctx->common, dir_count);
+       ret = start_file_metadata_phase(&ctx->common, full_count);
        if (ret)
                goto out;
 
-       ret = unix_set_dir_metadata(dentry_list, ctx);
+       ret = unix_apply_metadata(dentry_list, ctx);
        if (ret)
                goto out;