X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Fmount_image.c;h=ac993e17b2f7f54cc366780832c84b30ee5a865a;hp=41478d92a43dd8566c83c53a3f15bc35ff48c01a;hb=ad8c3f70361e25b7c1bbc46d4429749c7215fa12;hpb=dabcd6fe9a32f58709c513d6bf641773baa8f6aa

diff --git a/src/mount_image.c b/src/mount_image.c
index 41478d92..ac993e17 100644
--- a/src/mount_image.c
+++ b/src/mount_image.c
@@ -8,7 +8,7 @@
  */
 
 /*
- * Copyright (C) 2012, 2013 Eric Biggers
+ * Copyright (C) 2012, 2013, 2014 Eric Biggers
  *
  * This file is part of wimlib, a library for working with WIM files.
  *
@@ -114,6 +114,10 @@ struct wimfs_context {
 	/* List of inodes in the mounted image */
 	struct list_head *image_inode_list;
 
+	/* Original list of streams in the mounted image, linked by
+	 * mount_orig_stream_list.  */
+	struct list_head orig_stream_list;
+
 	/* Name and message queue descriptors for message queues between the
 	 * filesystem daemon process and the unmount process.  These are used
 	 * when the filesystem is unmounted and the process running
@@ -176,7 +180,7 @@ flags_writable(int open_flags)
  * @lte:	Lookup table entry for the stream (may be NULL)
  * @fd_ret:	Return the allocated file descriptor if successful.
  *
- * Return 0 iff successful or error code if unsuccessful.
+ * Return 0 iff successful or negative error code if unsuccessful.
  */
 static int
 alloc_wimfs_fd(struct wim_inode *inode,
@@ -186,7 +190,6 @@ alloc_wimfs_fd(struct wim_inode *inode,
 {
 	static const u16 fds_per_alloc = 8;
 	static const u16 max_fds = 0xffff;
-	int ret;
 
 	DEBUG("Allocating fd for stream ID %u from inode %#"PRIx64" "
 	      "(open = %u, allocated = %u)",
@@ -197,20 +200,18 @@ alloc_wimfs_fd(struct wim_inode *inode,
 		struct wimfs_fd **fds;
 		u16 num_new_fds;
 
-		if (inode->i_num_allocated_fds == max_fds) {
-			ret = -EMFILE;
-			goto out;
-		}
+		if (inode->i_num_allocated_fds == max_fds)
+			return -EMFILE;
+
 		num_new_fds = min(fds_per_alloc,
 				  max_fds - inode->i_num_allocated_fds);
 
 		fds = REALLOC(inode->i_fds,
 			      (inode->i_num_allocated_fds + num_new_fds) *
 			        sizeof(inode->i_fds[0]));
-		if (!fds) {
-			ret = -ENOMEM;
-			goto out;
-		}
+		if (!fds)
+			return -ENOMEM;
+
 		memset(&fds[inode->i_num_allocated_fds], 0,
 		       num_new_fds * sizeof(fds[0]));
 		inode->i_fds = fds;
@@ -219,10 +220,9 @@ alloc_wimfs_fd(struct wim_inode *inode,
 	for (u16 i = 0; ; i++) {
 		if (!inode->i_fds[i]) {
 			struct wimfs_fd *fd = CALLOC(1, sizeof(*fd));
-			if (!fd) {
-				ret = -ENOMEM;
-				break;
-			}
+			if (!fd)
+				return -ENOMEM;
+
 			fd->f_inode     = inode;
 			fd->f_lte       = lte;
 			filedes_invalidate(&fd->staging_fd);
@@ -234,12 +234,9 @@ alloc_wimfs_fd(struct wim_inode *inode,
 			if (lte)
 				lte->num_opened_fds++;
 			DEBUG("Allocated fd (idx = %u)", fd->idx);
-			ret = 0;
-			break;
+			return 0;
 		}
 	}
-out:
-	return ret;
 }
 
 static void
@@ -394,7 +391,7 @@ remove_dentry(struct wim_dentry *dentry,
 	unsigned i;
 
 	for (i = 0; i <= inode->i_num_ads; i++) {
-		lte = inode_stream_lte_resolved(inode, i);
+		lte = inode_stream_lte(inode, i, lookup_table);
 		if (lte)
 			lte_decrement_refcnt(lte, lookup_table);
 	}
@@ -1107,7 +1104,9 @@ send_unmount_request_msg(mqd_t mq, int unmount_flags, u8 want_progress_messages)
 	DEBUG("Sending unmount request msg");
 	struct msg_unmount_request msg = {
 		.hdr = {
-			.min_version = WIMLIB_MAKEVERSION(1, 2, 1),
+			.min_version = ((unmount_flags & WIMLIB_UNMOUNT_FLAG_NEW_IMAGE) ?
+						WIMLIB_MAKEVERSION(1, 6, 2) :
+						WIMLIB_MAKEVERSION(1, 2, 1)),
 			.cur_version = WIMLIB_VERSION_CODE,
 			.msg_type    = MSG_TYPE_UNMOUNT_REQUEST,
 			.msg_size    = sizeof(msg),
@@ -1187,6 +1186,80 @@ unmount_progress_func(enum wimlib_progress_msg msg,
 	return 0;
 }
 
+static void
+release_extra_refcnts(struct wimfs_context *ctx)
+{
+	struct list_head *list = &ctx->orig_stream_list;
+	struct wim_lookup_table *lookup_table = ctx->wim->lookup_table;
+	struct wim_lookup_table_entry *lte, *tmp;
+
+	list_for_each_entry_safe(lte, tmp, list, orig_stream_list) {
+		u32 n = lte->out_refcnt;
+		while (n--)
+			lte_decrement_refcnt(lte, lookup_table);
+	}
+}
+
+/* Moves the currently selected image, which may have been modified, to a new
+ * index, and sets the original index to refer to a reset (unmodified) copy of
+ * the image.  */
+static int
+renew_current_image(struct wimfs_context *ctx)
+{
+	WIMStruct *wim = ctx->wim;
+	int ret;
+	int idx = wim->current_image - 1;
+	struct wim_image_metadata *imd = wim->image_metadata[idx];
+	struct wim_image_metadata *replace_imd;
+	struct wim_lookup_table_entry *new_lte;
+
+	if (imd->metadata_lte->resource_location != RESOURCE_IN_WIM) {
+		ERROR("Can't reset modified image that doesn't yet "
+		      "exist in the on-disk WIM file!");
+		return WIMLIB_ERR_METADATA_NOT_FOUND;
+	}
+
+	/* Create 'replace_imd' structure to use for the reset original,
+	 * unmodified image.  */
+	replace_imd = new_image_metadata();
+	if (!replace_imd)
+		return WIMLIB_ERR_NOMEM;
+
+	/* Create new stream reference for the modified image's metadata
+	 * resource, which doesn't exist yet.  */
+	ret = WIMLIB_ERR_NOMEM;
+	new_lte = new_lookup_table_entry();
+	if (!new_lte)
+		goto err_put_replace_imd;
+	new_lte->flags = WIM_RESHDR_FLAG_METADATA;
+	new_lte->unhashed = 1;
+
+	/* Make the image being moved available at a new index.  Increments the
+	 * WIM's image count, but does not increment the reference count of the
+	 * 'struct image_metadata'.  */
+	ret = append_image_metadata(wim, imd);
+	if (ret)
+		goto err_free_new_lte;
+
+	ret = xml_add_image(wim, T(""));
+	if (ret)
+		goto err_undo_append;
+
+	replace_imd->metadata_lte = imd->metadata_lte;
+	imd->metadata_lte = new_lte;
+	wim->image_metadata[idx] = replace_imd;
+	wim->current_image = wim->hdr.image_count;
+	return 0;
+
+err_undo_append:
+	wim->hdr.image_count--;
+err_free_new_lte:
+	free_lookup_table_entry(new_lte);
+err_put_replace_imd:
+	put_image_metadata(replace_imd, NULL);
+	return ret;
+}
+
 static int
 msg_unmount_request_handler(const void *_msg, void *_handler_ctx)
 {
@@ -1221,6 +1294,18 @@ msg_unmount_request_handler(const void *_msg, void *_handler_ctx)
 
 	if (wimfs_ctx->mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
 		if (unmount_flags & WIMLIB_UNMOUNT_FLAG_COMMIT) {
+
+			if (unmount_flags & WIMLIB_UNMOUNT_FLAG_NEW_IMAGE) {
+				ret = renew_current_image(wimfs_ctx);
+				if (ret) {
+					status = ret;
+					goto out;
+				}
+			} else {
+				release_extra_refcnts(wimfs_ctx);
+			}
+			INIT_LIST_HEAD(&wimfs_ctx->orig_stream_list);
+
 			int write_flags = 0;
 			if (unmount_flags & WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY)
 				write_flags |= WIMLIB_WRITE_FLAG_CHECK_INTEGRITY;
@@ -1962,32 +2047,6 @@ wimfs_read(const char *path, char *buf, size_t size,
 	return ret;
 }
 
-struct fill_params {
-	void *buf;
-	fuse_fill_dir_t filler;
-};
-
-static int
-dentry_fuse_fill(struct wim_dentry *dentry, void *arg)
-{
-	struct fill_params *fill_params = arg;
-
-	char *file_name_mbs;
-	size_t file_name_mbs_nbytes;
-	int ret;
-
-	ret = utf16le_to_tstr(dentry->file_name,
-			      dentry->file_name_nbytes,
-			      &file_name_mbs,
-			      &file_name_mbs_nbytes);
-	if (ret)
-		return -errno;
-
-	ret = fill_params->filler(fill_params->buf, file_name_mbs, NULL, 0);
-	FREE(file_name_mbs);
-	return ret;
-}
-
 /* Fills in the entries of the directory specified by @path using the
  * FUSE-provided function @filler.  */
 static int
@@ -1996,22 +2055,38 @@ wimfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
 {
 	struct wimfs_fd *fd = (struct wimfs_fd*)(uintptr_t)fi->fh;
 	struct wim_inode *inode;
+	struct wim_dentry *child;
+	int ret;
 
 	if (!fd)
 		return -EBADF;
 
 	inode = fd->f_inode;
 
-	struct fill_params fill_params = {
-		.buf = buf,
-		.filler = filler,
-	};
+	ret = filler(buf, ".", NULL, 0);
+	if (ret)
+		return ret;
+	ret = filler(buf, "..", NULL, 0);
+	if (ret)
+		return ret;
 
-	filler(buf, ".", NULL, 0);
-	filler(buf, "..", NULL, 0);
+	for_inode_child(child, inode) {
+		char *file_name_mbs;
+		size_t file_name_mbs_nbytes;
 
-	return for_dentry_in_rbtree(inode->i_children.rb_node,
-				    dentry_fuse_fill, &fill_params);
+		ret = utf16le_to_tstr(child->file_name,
+				      child->file_name_nbytes,
+				      &file_name_mbs,
+				      &file_name_mbs_nbytes);
+		if (ret)
+			return -errno;
+
+		ret = filler(buf, file_name_mbs, NULL, 0);
+		FREE(file_name_mbs);
+		if (ret)
+			return ret;
+	}
+	return 0;
 }
 
 
@@ -2262,14 +2337,12 @@ wimfs_unlink(const char *path)
 static int
 wimfs_utimens(const char *path, const struct timespec tv[2])
 {
-	struct wim_dentry *dentry;
 	struct wim_inode *inode;
 	WIMStruct *wim = wimfs_get_WIMStruct();
 
-	dentry = get_dentry(wim, path, WIMLIB_CASE_SENSITIVE);
-	if (!dentry)
+	inode = wim_pathname_to_inode(wim, path);
+	if (!inode)
 		return -errno;
-	inode = dentry->d_inode;
 
 	if (tv[0].tv_nsec != UTIME_OMIT) {
 		if (tv[0].tv_nsec == UTIME_NOW)
@@ -2289,14 +2362,12 @@ wimfs_utimens(const char *path, const struct timespec tv[2])
 static int
 wimfs_utime(const char *path, struct utimbuf *times)
 {
-	struct wim_dentry *dentry;
 	struct wim_inode *inode;
 	WIMStruct *wim = wimfs_get_WIMStruct();
 
-	dentry = get_dentry(wim, path, WIMLIB_CASE_SENSITIVE);
-	if (!dentry)
+	inode = wim_pathname_to_inode(wim, path);
+	if (!inode)
 		return -errno;
-	inode = dentry->d_inode;
 
 	inode->i_last_write_time = unix_timestamp_to_wim(times->modtime);
 	inode->i_last_access_time = unix_timestamp_to_wim(times->actime);
@@ -2531,16 +2602,45 @@ wimlib_mount_image(WIMStruct *wim, int image, const char *dir,
 	}
 #endif
 
-	/* Mark dentry tree as modified if read-write mount. */
-	if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE)
+	/* Assign inode numbers.  Also, if a read-write mount was requested,
+	 * mark the dentry tree as modified, and add each stream referenced by
+	 * files in the image to a list and preemptively double the number of
+	 * references to each.  The latter is done to allow implementing the
+	 * WIMLIB_UNMOUNT_FLAG_NEW_IMAGE semantics.  */
+	ctx.next_ino = 1;
+	INIT_LIST_HEAD(&ctx.orig_stream_list);
+	if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) {
 		imd->modified = 1;
+		image_for_each_inode(inode, imd) {
+			inode->i_ino = ctx.next_ino++;
+			for (unsigned i = 0; i <= inode->i_num_ads; i++) {
+				struct wim_lookup_table_entry *lte;
+
+				lte = inode_stream_lte(inode, i, wim->lookup_table);
+				if (lte)
+					lte->out_refcnt = 0;
+			}
+		}
+		image_for_each_inode(inode, imd) {
+			for (unsigned i = 0; i <= inode->i_num_ads; i++) {
+				struct wim_lookup_table_entry *lte;
+
+				lte = inode_stream_lte(inode, i,
+						       wim->lookup_table);
+				if (lte) {
+					if (lte->out_refcnt == 0)
+						list_add(&lte->orig_stream_list,
+							 &ctx.orig_stream_list);
+					lte->out_refcnt += inode->i_nlink;
+					lte->refcnt += inode->i_nlink;
+				}
+			}
+		}
+	} else {
+		image_for_each_inode(inode, imd)
+			inode->i_ino = ctx.next_ino++;
+	}
 
-	/* Resolve the lookup table entries for every inode in the image, and
-	 * assign inode numbers */
-	DEBUG("Resolving lookup table entries and assigning inode numbers");
-	ctx.next_ino = 1;
-	image_for_each_inode(inode, imd)
-		inode->i_ino = ctx.next_ino++;
 	DEBUG("(next_ino = %"PRIu64")", ctx.next_ino);
 
 	DEBUG("Calling fuse_main()");
@@ -2562,6 +2662,8 @@ wimlib_mount_image(WIMStruct *wim, int image, const char *dir,
 		close_message_queues(&ctx);
 	}
 
+	release_extra_refcnts(&ctx);
+
 	/* Try to delete the staging directory if a deletion wasn't yet
 	 * attempted due to an earlier error */
 	if (ctx.staging_dir_name)
@@ -2587,7 +2689,8 @@ wimlib_unmount_image(const char *dir, int unmount_flags,
 			      WIMLIB_UNMOUNT_FLAG_COMMIT |
 			      WIMLIB_UNMOUNT_FLAG_REBUILD |
 			      WIMLIB_UNMOUNT_FLAG_RECOMPRESS |
-			      WIMLIB_UNMOUNT_FLAG_LAZY))
+			      WIMLIB_UNMOUNT_FLAG_LAZY |
+			      WIMLIB_UNMOUNT_FLAG_NEW_IMAGE))
 		return WIMLIB_ERR_INVALID_PARAM;
 
 	init_wimfs_context(&wimfs_ctx);