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lib/commit: don't query devino cache for modified files
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We can't use the cache if the file we want to commit has been modified
by the client through the file info or xattr modifiers. We would
prematurely look into the cache in `write_dfd_iter_to_mtree_internal`,
regardless of whether any filtering applied.

We remove that path there, and make sure that we only use the cache if
there were no modifications. We rename the `get_modified_xattrs` to
`get_final_xattrs` to reflect the fact that the xattrs may not be
modified.

One tricky bit that took me some time was that we now need to store the
st_dev & st_ino values in the GFileInfo because the cache lookup relies
on it. I'm guessing we regressed on this at some point.

This patch does slightly change the semantics of the xattr callback.
Previously, returning NULL from the cb meant no xattrs at all. Now, it
means to default to the on-disk state. We might want to consider putting
that behind a flag instead. Though it seems like a more useful behaviour
so that callers can only override the files they want to without losing
original on-disk state (and if they don't want that, just return an
empty GVariant).

Closes: #1165

Closes: #1170
Approved by: cgwalters
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@jlebon @rh-atomic-bot
jlebon authored and rh-atomic-bot committed Sep 28, 2017
1 parent 89f4926 commit d6e76b2
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Showing 5 changed files with 247 additions and 64 deletions.
1 change: 1 addition & 0 deletions src/libostree/ostree-core-private.h
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Original file line number Diff line number Diff line change
Expand Up @@ -89,6 +89,7 @@ _ostree_make_temporary_symlink_at (int tmp_dirfd,
GError **error);

GFileInfo * _ostree_stbuf_to_gfileinfo (const struct stat *stbuf);
gboolean _ostree_gfileinfo_equal (GFileInfo *a, GFileInfo *b);
GFileInfo * _ostree_mode_uidgid_to_gfileinfo (mode_t mode, uid_t uid, gid_t gid);

static inline void
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40 changes: 40 additions & 0 deletions src/libostree/ostree-core.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1568,12 +1568,52 @@ _ostree_stbuf_to_gfileinfo (const struct stat *stbuf)
g_file_info_set_attribute_uint32 (ret, "unix::uid", stbuf->st_uid);
g_file_info_set_attribute_uint32 (ret, "unix::gid", stbuf->st_gid);
g_file_info_set_attribute_uint32 (ret, "unix::mode", mode);

/* those aren't stored by ostree, but used by the devino cache */
g_file_info_set_attribute_uint32 (ret, "unix::device", stbuf->st_dev);
g_file_info_set_attribute_uint64 (ret, "unix::inode", stbuf->st_ino);

if (S_ISREG (mode))
g_file_info_set_attribute_uint64 (ret, "standard::size", stbuf->st_size);

return ret;
}

/**
* _ostree_gfileinfo_equal:
* @a: First file info
* @b: Second file info
*
* OSTree only cares about a subset of file attributes. This function
* checks whether two #GFileInfo objects are equal as far as OSTree is
* concerned.
*
* Returns: TRUE if the #GFileInfo objects are OSTree-equivalent.
*/
gboolean
_ostree_gfileinfo_equal (GFileInfo *a, GFileInfo *b)
{
/* trivial case */
if (a == b)
return TRUE;

#define CHECK_ONE_ATTR(type, attr, a, b) \
do { if (g_file_info_get_attribute_##type(a, attr) != \
g_file_info_get_attribute_##type(b, attr)) \
return FALSE; \
} while (0)

CHECK_ONE_ATTR (uint32, "unix::uid", a, b);
CHECK_ONE_ATTR (uint32, "unix::gid", a, b);
CHECK_ONE_ATTR (uint32, "unix::mode", a, b);
CHECK_ONE_ATTR (uint32, "standard::type", a, b);
CHECK_ONE_ATTR (uint64, "standard::size", a, b);

#undef CHECK_ONE_ATTR

return TRUE;
}

GFileInfo *
_ostree_mode_uidgid_to_gfileinfo (mode_t mode, uid_t uid, gid_t gid)
{
Expand Down
128 changes: 66 additions & 62 deletions src/libostree/ostree-repo-commit.c
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Original file line number Diff line number Diff line change
Expand Up @@ -2363,58 +2363,67 @@ ptrarray_path_join (GPtrArray *path)
}

static gboolean
get_modified_xattrs (OstreeRepo *self,
OstreeRepoCommitModifier *modifier,
const char *relpath,
GFileInfo *file_info,
GFile *path,
int dfd,
const char *dfd_subpath,
GVariant **out_xattrs,
GCancellable *cancellable,
GError **error)
{
g_autoptr(GVariant) ret_xattrs = NULL;

if (modifier && modifier->xattr_callback)
{
ret_xattrs = modifier->xattr_callback (self, relpath, file_info,
modifier->xattr_user_data);
}
else if (!(modifier && (modifier->flags & (OSTREE_REPO_COMMIT_MODIFIER_FLAGS_SKIP_XATTRS |
OSTREE_REPO_COMMIT_MODIFIER_FLAGS_CANONICAL_PERMISSIONS)) > 0)
&& !self->disable_xattrs)
get_final_xattrs (OstreeRepo *self,
OstreeRepoCommitModifier *modifier,
const char *relpath,
GFileInfo *file_info,
GFile *path,
int dfd,
const char *dfd_subpath,
GVariant **out_xattrs,
gboolean *out_modified,
GCancellable *cancellable,
GError **error)
{
/* track whether the returned xattrs differ from the file on disk */
gboolean modified = TRUE;

/* fetch on-disk xattrs if needed & not disabled */
g_autoptr(GVariant) original_xattrs = NULL;
if (!(modifier && (modifier->flags & (OSTREE_REPO_COMMIT_MODIFIER_FLAGS_SKIP_XATTRS |
OSTREE_REPO_COMMIT_MODIFIER_FLAGS_CANONICAL_PERMISSIONS)) > 0)
&& !self->disable_xattrs)
{
if (path && OSTREE_IS_REPO_FILE (path))
{
if (!ostree_repo_file_get_xattrs (OSTREE_REPO_FILE (path),
&ret_xattrs,
cancellable,
error))
if (!ostree_repo_file_get_xattrs (OSTREE_REPO_FILE (path), &original_xattrs,
cancellable, error))
return FALSE;
}
else if (path)
{
if (!glnx_dfd_name_get_all_xattrs (AT_FDCWD, gs_file_get_path_cached (path),
&ret_xattrs, cancellable, error))
&original_xattrs, cancellable, error))
return FALSE;
}
else if (dfd_subpath == NULL)
{
g_assert (dfd != -1);
if (!glnx_fd_get_all_xattrs (dfd, &ret_xattrs,
cancellable, error))
if (!glnx_fd_get_all_xattrs (dfd, &original_xattrs, cancellable, error))
return FALSE;
}
else
{
g_assert (dfd != -1);
if (!glnx_dfd_name_get_all_xattrs (dfd, dfd_subpath, &ret_xattrs,
cancellable, error))
if (!glnx_dfd_name_get_all_xattrs (dfd, dfd_subpath, &original_xattrs,
cancellable, error))
return FALSE;
}

g_assert (original_xattrs);
}

g_autoptr(GVariant) ret_xattrs = NULL;
if (modifier && modifier->xattr_callback)
{
ret_xattrs = modifier->xattr_callback (self, relpath, file_info,
modifier->xattr_user_data);
}

/* if callback returned NULL or didn't exist, default to on-disk state */
if (!ret_xattrs && original_xattrs)
ret_xattrs = g_variant_ref (original_xattrs);

if (modifier && modifier->sepolicy)
{
g_autofree char *label = NULL;
Expand All @@ -2436,10 +2445,9 @@ get_modified_xattrs (OstreeRepo *self,
{
/* drop out any existing SELinux policy from the set, so we don't end up
* counting it twice in the checksum */
g_autoptr(GVariant) new_ret_xattrs = NULL;
new_ret_xattrs = _ostree_filter_selinux_xattr (ret_xattrs);
GVariant* new_ret_xattrs = _ostree_filter_selinux_xattr (ret_xattrs);
g_variant_unref (ret_xattrs);
ret_xattrs = g_steal_pointer (&new_ret_xattrs);
ret_xattrs = new_ret_xattrs;
}

/* ret_xattrs may be NULL */
Expand All @@ -2458,8 +2466,13 @@ get_modified_xattrs (OstreeRepo *self,
}
}

if (original_xattrs && ret_xattrs && g_variant_equal (original_xattrs, ret_xattrs))
modified = FALSE;

if (out_xattrs)
*out_xattrs = g_steal_pointer (&ret_xattrs);
if (out_modified)
*out_modified = modified;
return TRUE;
}

Expand Down Expand Up @@ -2506,6 +2519,7 @@ write_directory_content_to_mtree_internal (OstreeRepo *self,
g_autoptr(GFileInfo) modified_info = NULL;
OstreeRepoCommitFilterResult filter_result =
_ostree_repo_commit_modifier_apply (self, modifier, child_relpath, child_info, &modified_info);
const gboolean child_info_was_modified = !_ostree_gfileinfo_equal (child_info, modified_info);

if (filter_result != OSTREE_REPO_COMMIT_FILTER_ALLOW)
{
Expand Down Expand Up @@ -2567,16 +2581,26 @@ write_directory_content_to_mtree_internal (OstreeRepo *self,
else
{
guint64 file_obj_length;
const char *loose_checksum;
g_autoptr(GInputStream) file_input = NULL;
g_autoptr(GVariant) xattrs = NULL;
g_autoptr(GInputStream) file_object_input = NULL;
g_autofree guchar *child_file_csum = NULL;
g_autofree char *tmp_checksum = NULL;

loose_checksum = devino_cache_lookup (self, modifier,
g_file_info_get_attribute_uint32 (child_info, "unix::device"),
g_file_info_get_attribute_uint64 (child_info, "unix::inode"));
g_autoptr(GVariant) xattrs = NULL;
gboolean xattrs_were_modified;
if (!get_final_xattrs (self, modifier, child_relpath, child_info, child,
dfd_iter != NULL ? dfd_iter->fd : -1, name, &xattrs,
&xattrs_were_modified, cancellable, error))
return FALSE;

/* only check the devino cache if the file info & xattrs were not modified */
const char *loose_checksum = NULL;
if (!child_info_was_modified && !xattrs_were_modified)
{
guint32 dev = g_file_info_get_attribute_uint32 (child_info, "unix::device");
guint64 inode = g_file_info_get_attribute_uint64 (child_info, "unix::inode");
loose_checksum = devino_cache_lookup (self, modifier, dev, inode);
}

if (loose_checksum)
{
Expand All @@ -2602,12 +2626,6 @@ write_directory_content_to_mtree_internal (OstreeRepo *self,
}
}

if (!get_modified_xattrs (self, modifier,
child_relpath, child_info, child, dfd_iter != NULL ? dfd_iter->fd : -1, name,
&xattrs,
cancellable, error))
return FALSE;

if (!ostree_raw_file_to_content_stream (file_input,
modified_info, xattrs,
&file_object_input, &file_obj_length,
Expand Down Expand Up @@ -2681,10 +2699,8 @@ write_directory_to_mtree_internal (OstreeRepo *self,

if (filter_result == OSTREE_REPO_COMMIT_FILTER_ALLOW)
{
if (!get_modified_xattrs (self, modifier, relpath, child_info,
dir, -1, NULL,
&xattrs,
cancellable, error))
if (!get_final_xattrs (self, modifier, relpath, child_info, dir, -1, NULL,
&xattrs, NULL, cancellable, error))
return FALSE;

g_autofree guchar *child_file_csum = NULL;
Expand Down Expand Up @@ -2768,10 +2784,8 @@ write_dfd_iter_to_mtree_internal (OstreeRepo *self,

if (filter_result == OSTREE_REPO_COMMIT_FILTER_ALLOW)
{
if (!get_modified_xattrs (self, modifier, relpath, modified_info,
NULL, src_dfd_iter->fd, NULL,
&xattrs,
cancellable, error))
if (!get_final_xattrs (self, modifier, relpath, modified_info, NULL, src_dfd_iter->fd,
NULL, &xattrs, NULL, cancellable, error))
return FALSE;

if (!_ostree_repo_write_directory_meta (self, modified_info, xattrs, &child_file_csum,
Expand Down Expand Up @@ -2801,16 +2815,6 @@ write_dfd_iter_to_mtree_internal (OstreeRepo *self,
if (!glnx_fstatat (src_dfd_iter->fd, dent->d_name, &stbuf, AT_SYMLINK_NOFOLLOW, error))
return FALSE;

const char *loose_checksum = devino_cache_lookup (self, modifier, stbuf.st_dev, stbuf.st_ino);
if (loose_checksum)
{
if (!ostree_mutable_tree_replace_file (mtree, dent->d_name, loose_checksum,
error))
return FALSE;

continue;
}

g_autoptr(GFileInfo) child_info = _ostree_stbuf_to_gfileinfo (&stbuf);
g_file_info_set_name (child_info, dent->d_name);

Expand Down
20 changes: 19 additions & 1 deletion tests/basic-test.sh
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,7 +19,7 @@

set -euo pipefail

echo "1..$((72 + ${extra_basic_tests:-0}))"
echo "1..$((73 + ${extra_basic_tests:-0}))"

CHECKOUT_U_ARG=""
CHECKOUT_H_ARGS="-H"
Expand Down Expand Up @@ -602,6 +602,24 @@ $OSTREE checkout test2 test2-checkout
(cd test2-checkout && $OSTREE commit ${COMMIT_ARGS} --link-checkout-speedup -b test2 -s "tmp")
echo "ok commit with link speedup"

cd ${test_tmpdir}
rm -rf test2-checkout
$OSTREE checkout test2 test2-checkout
# set cow to different perms, but re-set cowro to the same perms
cat > statoverride.txt <<EOF
=$((0600)) /baz/cow
=$((0600)) /baz/cowro
EOF
$OSTREE commit ${COMMIT_ARGS} --statoverride=statoverride.txt \
--table-output --link-checkout-speedup -b test2-tmp test2-checkout > stats.txt
$OSTREE diff test2 test2-tmp > diff-test2
assert_file_has_content diff-test2 'M */baz/cow$'
assert_not_file_has_content diff-test2 'M */baz/cowro$'
assert_not_file_has_content diff-test2 'baz/saucer'
# only /baz/cow is a cache miss
assert_file_has_content stats.txt '^Content Written: 1$'
echo "ok commit with link speedup and modifier"

cd ${test_tmpdir}
$OSTREE ls test2
echo "ok ls with no argument"
Expand Down
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