packaging/ostree
1
0 Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

lib/checkout: Rename disjoint union, change to merge identical files

Browse Source 
It turns out that librpm automatically merges identical files between
distinct packages, and this occurs in practice with Fedora today between
`chkconfig` and `initscripts` for exmaple.

Since we added this for rpm-ostree, we basically want to do what librpm does,
let's change the semantics to do a merge.  While we're here rename
to `UNION_IDENTICAL`.

Closes: #1156
Approved by: jlebon
This commit is contained in:
Colin Walters authored and Atomic Bot committed 2017-09-13 19:19:33 +00:00
1 parent 8d3752a0d6
commit 051cdf396c
6 files changed
+208 -86
Download Patch File Download Diff File Expand all files Collapse all files

No files matched your search

src/libostree/ostree-repo-checkout.c
+129 -47
View File
@@ -188,8 +188,6 @@ create_file_copy_from_input_at (OstreeRepo *repo,
GCancellable *cancellable,
GError **error)
{
const gboolean union_mode = options->overwrite_mode == OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES;
const gboolean add_mode = options->overwrite_mode == OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES;
const gboolean sepolicy_enabled = options->sepolicy && !repo->disable_xattrs;
g_autoptr(GVariant) modified_xattrs = NULL;
@@ -218,23 +216,51 @@ create_file_copy_from_input_at (OstreeRepo *repo,
return FALSE;
}
if (symlinkat (g_file_info_get_symlink_target (file_info),
destination_dfd, destination_name) < 0)
const char *target = g_file_info_get_symlink_target (file_info);
if (symlinkat (target, destination_dfd, destination_name) < 0)
{
if (errno != EEXIST)
return glnx_throw_errno_prefix (error, "symlinkat");
/* Handle union/add behaviors if we get EEXIST */
if (errno == EEXIST && union_mode)
switch (options->overwrite_mode)
{
/* Unioning? Let's unlink and try again */
(void) unlinkat (destination_dfd, destination_name, 0);
if (symlinkat (g_file_info_get_symlink_target (file_info),
destination_dfd, destination_name) < 0)
return glnx_throw_errno (error);
case OSTREE_REPO_CHECKOUT_OVERWRITE_NONE:
return glnx_throw_errno_prefix (error, "symlinkat");
case OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES:
{
/* Unioning? Let's unlink and try again */
(void) unlinkat (destination_dfd, destination_name, 0);
if (symlinkat (target, destination_dfd, destination_name) < 0)
return glnx_throw_errno_prefix (error, "symlinkat");
}
case OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES:
/* Note early return - we don't want to set the xattrs below */
return TRUE;
case OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_IDENTICAL:
{
/* See the comments for the hardlink version of this
* for why we do this.
*/
struct stat dest_stbuf;
if (!glnx_fstatat (destination_dfd, destination_name, &dest_stbuf,
AT_SYMLINK_NOFOLLOW, error))
return FALSE;
if (S_ISLNK (dest_stbuf.st_mode))
{
g_autofree char *dest_target =
glnx_readlinkat_malloc (destination_dfd, destination_name,
cancellable, error);
if (!dest_target)
return FALSE;
/* In theory we could also compare xattrs...but eh */
if (g_str_equal (dest_target, target))
return TRUE;
}
errno = EEXIST;
return glnx_throw_errno_prefix (error, "symlinkat");
}
}
else if (errno == EEXIST && add_mode)
/* Note early return - we don't want to set the xattrs below */
return TRUE;
else
return glnx_throw_errno (error);
}
/* Process ownership and xattrs now that we made the link */
@@ -255,7 +281,6 @@ create_file_copy_from_input_at (OstreeRepo *repo,
else if (g_file_info_get_file_type (file_info) == G_FILE_TYPE_REGULAR)
{
g_auto(GLnxTmpfile) tmpf = { 0, };
GLnxLinkTmpfileReplaceMode replace_mode;
if (!glnx_open_tmpfile_linkable_at (destination_dfd, ".", O_WRONLY | O_CLOEXEC,
&tmpf, error))
@@ -278,12 +303,23 @@ create_file_copy_from_input_at (OstreeRepo *repo,
return FALSE;
/* The add/union/none behaviors map directly to GLnxLinkTmpfileReplaceMode */
if (add_mode)
replace_mode = GLNX_LINK_TMPFILE_NOREPLACE_IGNORE_EXIST;
else if (union_mode)
replace_mode = GLNX_LINK_TMPFILE_REPLACE;
else
replace_mode = GLNX_LINK_TMPFILE_NOREPLACE;
GLnxLinkTmpfileReplaceMode replace_mode;
switch (options->overwrite_mode)
{
case OSTREE_REPO_CHECKOUT_OVERWRITE_NONE:
replace_mode = GLNX_LINK_TMPFILE_NOREPLACE;
break;
case OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES:
replace_mode = GLNX_LINK_TMPFILE_REPLACE;
break;
case OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES:
replace_mode = GLNX_LINK_TMPFILE_NOREPLACE_IGNORE_EXIST;
break;
case OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_IDENTICAL:
/* We don't support copying in union identical */
g_assert_not_reached ();
break;
}
if (!glnx_link_tmpfile_at (&tmpf, replace_mode,
destination_dfd, destination_name,
@@ -329,25 +365,61 @@ checkout_file_hardlink (OstreeRepo *self,
else if (allow_noent && errno == ENOENT)
{
}
else if (errno == EEXIST && options->overwrite_mode == OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES)
else if (errno == EEXIST)
{
/* In this mode, we keep existing content. Distinguish this case though to
* avoid inserting into the devino cache.
*/
ret_result = HARDLINK_RESULT_SKIP_EXISTED;
}
else if (errno == EEXIST && options->overwrite_mode == OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES)
{
/* Idiocy, from man rename(2)
*
* "If oldpath and newpath are existing hard links referring to
* the same file, then rename() does nothing, and returns a
* success status."
*
* So we can't make this atomic.
*/
(void) unlinkat (destination_dfd, destination_name, 0);
goto again;
/* When we get EEXIST, we need to handle the different overwrite modes. */
switch (options->overwrite_mode)
{
case OSTREE_REPO_CHECKOUT_OVERWRITE_NONE:
/* Just throw */
return glnx_throw_errno_prefix (error, "Hardlinking %s to %s", loose_path, destination_name);
case OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES:
/* In this mode, we keep existing content. Distinguish this case though to
* avoid inserting into the devino cache.
*/
ret_result = HARDLINK_RESULT_SKIP_EXISTED;
break;
case OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES:
{
/* Idiocy, from man rename(2)
*
* "If oldpath and newpath are existing hard links referring to
* the same file, then rename() does nothing, and returns a
* success status."
*
* So we can't make this atomic.
*/
(void) unlinkat (destination_dfd, destination_name, 0);
goto again;
}
case OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_IDENTICAL:
{
/* In this mode, we error out on EEXIST *unless* the files are already
* hardlinked, which is what rpm-ostree wants for package layering.
* https://github.com/projectatomic/rpm-ostree/issues/982
*
* This should be similar to the librpm version:
* https://github.com/rpm-software-management/rpm/blob/e3cd2bc85e0578f158d14e6f9624eb955c32543b/lib/rpmfi.c#L921
* in rpmfilesCompare().
*/
struct stat src_stbuf;
if (!glnx_fstatat (srcfd, loose_path, &src_stbuf,
AT_SYMLINK_NOFOLLOW, error))
return FALSE;
struct stat dest_stbuf;
if (!glnx_fstatat (destination_dfd, destination_name, &dest_stbuf,
AT_SYMLINK_NOFOLLOW, error))
return FALSE;
const gboolean is_identical =
(src_stbuf.st_dev == dest_stbuf.st_dev &&
src_stbuf.st_ino == dest_stbuf.st_ino);
if (is_identical)
ret_result = HARDLINK_RESULT_SKIP_EXISTED;
else
return glnx_throw_errno_prefix (error, "Hardlinking %s to %s", loose_path, destination_name);
break;
}
}
}
else
{
@@ -652,13 +724,20 @@ checkout_tree_at_recurse (OstreeRepo *self,
*/
if (TEMP_FAILURE_RETRY (mkdirat (destination_parent_fd, destination_name, 0700)) < 0)
{
if (errno == EEXIST &&
(options->overwrite_mode == OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES
|| options->overwrite_mode == OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES
|| options->overwrite_mode == OSTREE_REPO_CHECKOUT_OVERWRITE_DISJOINT_UNION_FILES))
did_exist = TRUE;
else
return glnx_throw_errno (error);
if (errno != EEXIST)
return glnx_throw_errno_prefix (error, "mkdirat");
switch (options->overwrite_mode)
{
case OSTREE_REPO_CHECKOUT_OVERWRITE_NONE:
return glnx_throw_errno_prefix (error, "mkdirat");
/* All of these cases are the same for directories */
case OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES:
case OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES:
case OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_IDENTICAL:
did_exist = TRUE;
break;
}
}
}
@@ -1002,6 +1081,9 @@ ostree_repo_checkout_at (OstreeRepo *self,
g_return_val_if_fail (!(options->force_copy && options->no_copy_fallback), FALSE);
g_return_val_if_fail (!options->sepolicy || options->force_copy, FALSE);
/* union identical requires hardlink mode */
g_return_val_if_fail (!(options->overwrite_mode == OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_IDENTICAL &&
!options->no_copy_fallback), FALSE);
g_autoptr(GFile) commit_root = (GFile*) _ostree_repo_file_new_for_commit (self, commit, error);
if (!commit_root)
src/libostree/ostree-repo.h
+2 -2
View File
@@ -832,13 +832,13 @@ typedef enum {
* @OSTREE_REPO_CHECKOUT_OVERWRITE_NONE: No special options
* @OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES: When layering checkouts, unlink() and replace existing files, but do not modify existing directories
* @OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES: Only add new files/directories
* @OSTREE_REPO_CHECKOUT_OVERWRITE_DISJOINT_UNION_FILES: When layering checkouts, error out if a file would be replaced, but add new files and directories
* @OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_IDENTICAL: Like UNION_FILES, but error if files are not identical (requires hardlink checkouts)
*/
typedef enum {
OSTREE_REPO_CHECKOUT_OVERWRITE_NONE = 0,
OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_FILES = 1,
OSTREE_REPO_CHECKOUT_OVERWRITE_ADD_FILES = 2, /* Since: 2017.3 */
OSTREE_REPO_CHECKOUT_OVERWRITE_DISJOINT_UNION_FILES = 3 /* Since: 2017.11 */
OSTREE_REPO_CHECKOUT_OVERWRITE_UNION_IDENTICAL = 3, /* Since: 2017.11 */
} OstreeRepoCheckoutOverwriteMode;
_OSTREE_PUBLIC