static const u16 fds_per_alloc = 8;
static const u16 max_fds = 0xffff;
- DEBUG("Allocate wimlib fd");
+ DEBUG("Allocating fd for stream ID %u from inode %lx (open = %u, allocated = %u)",
+ stream_id, inode->ino, inode->num_opened_fds,
+ inode->num_allocated_fds);
if (inode->num_opened_fds == inode->num_allocated_fds) {
struct wimlib_fd **fds;
static int close_wimlib_fd(struct wimlib_fd *fd)
{
int ret;
+ DEBUG("Closing fd (inode = %lu, opened = %u, allocated = %u)",
+ fd->inode->ino, fd->inode->num_opened_fds,
+ fd->inode->num_allocated_fds);
ret = lte_put_fd(fd->lte, fd);
if (ret != 0)
return ret;
*
* @inode: Inode that contains the stream we are extracting
*
+ * @stream_id: Identifier for the stream (it stays constant even if the indices
+ * of the stream entries are changed)
+ *
* @lte: Pointer to pointer to the lookup table entry for the stream we need to
* extract, or NULL if there was no lookup table entry present for the stream
*
goto out_delete_staging_file;
}
- if (old_lte) {
- wimlib_assert(old_lte->resource_location == RESOURCE_IN_WIM);
- if (inode->link_count == old_lte->refcnt) {
- /* The reference count of the existing lookup table
- * entry is the same as the size of the hard link group
- * associated with the dentry; therefore, ALL the
- * references to the lookup table entry correspond to
- * the stream we're trying to extract. So the lookup
- * table entry can be re-used.
- */
- DEBUG("Re-using lookup table entry");
- lookup_table_unlink(w->lookup_table, old_lte);
- new_lte = old_lte;
- } else {
+ if (old_lte && inode->link_count == old_lte->refcnt) {
+ /* The reference count of the existing lookup table
+ * entry is the same as the link count of the inode that
+ * contains the stream we're opening. Therefore, ALL
+ * the references to the lookup table entry correspond
+ * to the stream we're trying to extract, so the lookup
+ * table entry can be re-used. */
+ DEBUG("Re-using lookup table entry");
+ lookup_table_unlink(w->lookup_table, old_lte);
+ new_lte = old_lte;
+ } else {
+ if (old_lte) {
+ /* There's an existing lookup table entry, but its
+ * reference count is creater than the link count for
+ * the inode containing a stream we're opening.
+ * Therefore, we need to split the lookup table entry.
+ * */
+ wimlib_assert(old_lte->refcnt > inode->link_count);
DEBUG("Splitting lookup table entry "
- "(inode->link_count = %zu, lte refcnt = %u)",
+ "(inode->link_count = %zu, old_lte->refcnt = %u)",
inode->link_count, old_lte->refcnt);
- wimlib_assert(old_lte->refcnt > inode->link_count);
+ }
- new_lte = new_lookup_table_entry();
- if (!new_lte) {
- ret = -ENOMEM;
- goto out_delete_staging_file;
- }
- old_lte->refcnt -= inode->link_count;
+ new_lte = new_lookup_table_entry();
+ if (!new_lte) {
+ ret = -ENOMEM;
+ goto out_delete_staging_file;
+ }
- for (u16 i = 0, j = 0; j < inode->num_opened_fds; i++) {
- if (inode->fds[i]) {
- if (inode->fds[i]->stream_id == stream_id) {
- wimlib_assert(inode->fds[i]->lte == old_lte);
- inode->fds[i]->lte = new_lte;
+ /* There may already be open file descriptors to this stream if
+ * it's previously been opened read-only, but just now we're
+ * opening it read-write. Identify those file descriptors and
+ * change their lookup table entry pointers to point to the new
+ * lookup table entry, and open staging file descriptors for
+ * them.
+ *
+ * At the same time, we need to count the number of these opened
+ * file descriptors to the new lookup table entry. If there's
+ * an old lookup table entry, this number needs to be subtracted
+ * from the fd's opened to the old entry. */
+ for (u16 i = 0, j = 0; j < inode->num_opened_fds; i++) {
+ struct wimlib_fd *fd = inode->fds[i];
+ if (fd) {
+ if (fd->stream_id == stream_id) {
+ wimlib_assert(fd->lte == old_lte);
+ fd->lte = new_lte;
+ new_lte->num_opened_fds++;
+ fd->staging_fd = open(staging_file_name, O_RDONLY);
+ if (fd->staging_fd == -1) {
+ ret = -errno;
+ goto out_revert_fd_changes;
}
- j++;
}
+ j++;
}
}
- } else {
- /* No old_lte was supplied, so the resource had no lookup table
- * entry before (it must be an empty resource) */
- wimlib_assert(inode->num_opened_fds == 0);
- new_lte = new_lookup_table_entry();
- if (!new_lte) {
- ret = -ENOMEM;
- goto out_delete_staging_file;
+ DEBUG("%zu fd's were already opened to the file we extracted",
+ new_lte->num_opened_fds);
+ if (old_lte) {
+ old_lte->num_opened_fds -= new_lte->num_opened_fds;
+ old_lte->refcnt -= inode->link_count;
}
}
+
new_lte->resource_entry.original_size = size;
new_lte->refcnt = inode->link_count;
random_hash(new_lte->hash);
list_add(&new_lte->staging_list, &staging_list);
*lte = new_lte;
return 0;
+out_revert_fd_changes:
+ for (u16 i = 0, j = 0; j < new_lte->num_opened_fds; i++) {
+ struct wimlib_fd *fd = inode->fds[i];
+ if (fd && fd->stream_id == stream_id && fd->lte == new_lte) {
+ fd->lte = old_lte;
+ if (fd->staging_fd != -1) {
+ close(fd->staging_fd);
+ fd->staging_fd = -1;
+ }
+ j++;
+ }
+ }
+out_free_new_lte:
+ free_lookup_table_entry(new_lte);
out_delete_staging_file:
unlink(staging_file_name);
FREE(staging_file_name);
if (ret != 0)
return ret;
- DEBUG("dentry = %p", dentry);
-
inode = dentry->inode;
- DEBUG("stream_idx = %u", stream_idx);
-
if (stream_idx == 0)
stream_id = 0;
else
stream_id = inode->ads_entries[stream_idx - 1]->stream_id;
- DEBUG("stream_id = %u", stream_id);
-
/* The file resource may be in the staging directory (read-write mounts
* only) or in the WIM. If it's in the staging directory, we need to
* open a native file descriptor for the corresponding file. Otherwise,
* opening it read-only, but we need to extract the resource to the
* staging directory if we are opening it writable. */
if (flags_writable(fi->flags) &&
- lte->resource_location != RESOURCE_IN_STAGING_FILE) {
+ (!lte || lte->resource_location != RESOURCE_IN_STAGING_FILE)) {
+ u64 size = (lte) ? wim_resource_size(lte) : 0;
ret = extract_resource_to_staging_dir(inode, stream_id,
- <e,
- wim_resource_size(lte));
+ <e, size);
if (ret != 0)
return ret;
}
if (ret != 0)
return ret;
- if (lte->resource_location == RESOURCE_IN_STAGING_FILE) {
+ if (lte && lte->resource_location == RESOURCE_IN_STAGING_FILE) {
fd->staging_fd = open(lte->staging_file_name, fi->flags);
if (fd->staging_fd == -1) {
close_wimlib_fd(fd);
git://wimlib.net / wimlib / commitdiff