13.07.2016 14:48, Pavel Emelyanov пишет:
> On 06/30/2016 08:11 PM, Stanislav Kinsburskiy wrote:
>> Currently criu always creates link for each file, considered as "silly-renamed".
>> Even in those cases, when file is opened multiple times, it creates one new
>> link for each occurrence.
>> On restore only one link file is used for all the file descriptors, sharing
>> this path. And only this link is removed.
> Would you cook a zdtm test showing it?
Sorry, I don't understand. Showing what exactly?
I caught by using zdtm tests. Test "static/unlink_mmap00" should expose it.
Two links created, only one used and unlinked. Another one stays on the
disk.
>> The rest of the links are forgotten and abandoned on file system.
>> This patch fixed this mess by creating the link only iff it's unique. Or
>> skipping this job otherwise.
>>
>> Signed-off-by: Stanislav Kinsburskiy <skinsbursky at virtuozzo.com>
>> ---
>> criu/files-reg.c | 50 ++++++++++++++++++++++++++++++++++++++++++++------
>> 1 file changed, 44 insertions(+), 6 deletions(-)
>>
>> diff --git a/criu/files-reg.c b/criu/files-reg.c
>> index fd36ae9..b1ad271 100644
>> --- a/criu/files-reg.c
>> +++ b/criu/files-reg.c
>> @@ -70,9 +70,11 @@ struct link_remap_rlb {
>> struct list_head list;
>> struct ns_id *mnt_ns;
>> char *path;
>> + char *orig;
>> + u32 id;
>> };
>>
>> -static int note_link_remap(char *path, struct ns_id *nsid)
>> +static int note_link_remap(char *path, char *orig, struct ns_id *nsid, u32 id)
>> {
>> struct link_remap_rlb *rlb;
>>
>> @@ -84,11 +86,18 @@ static int note_link_remap(char *path, struct ns_id *nsid)
>> if (!rlb->path)
>> goto err2;
>>
>> + rlb->orig = strdup(orig);
>> + if (!rlb->orig)
>> + goto err3;
>> +
>> rlb->mnt_ns = nsid;
>> + rlb->id = id;
>> list_add(&rlb->list, &remaps);
>>
>> return 0;
>>
>> +err3:
>> + xfree(rlb->path);
>> err2:
>> xfree(rlb);
>> err:
>> @@ -96,6 +105,22 @@ err:
>> return -1;
>> }
>>
>> +static int find_link_remap(char *path, struct ns_id *nsid, u32 *id)
>> +{
>> + struct link_remap_rlb *rlb;
>> +
>> + list_for_each_entry(rlb, &remaps, list) {
>> + if (rlb->mnt_ns != nsid)
>> + continue;
>> + if (strcmp(rlb->orig, path))
>> + continue;
>> +
>> + *id = rlb->id;
>> + return 0;
>> + }
>> + return -ENOENT;
>> +}
>> +
>> /* Trim "a/b/c/d" to "a/b/d" */
>> static int trim_last_parent(char *path)
>> {
>> @@ -725,6 +750,7 @@ static void __rollback_link_remaps(bool do_unlink)
>> }
>>
>> list_del(&rlb->list);
>> + xfree(rlb->orig);
>> xfree(rlb->path);
>> xfree(rlb);
>> }
>> @@ -781,28 +807,40 @@ static int create_link_remap(char *path, int len, int lfd,
>> return -1;
>> }
>>
>> - if (note_link_remap(link_name, nsid))
>> + if (note_link_remap(link_name, path, nsid, *idp))
>> return -1;
>>
>> return pb_write_one(img_from_set(glob_imgset, CR_FD_REG_FILES), &rfe, PB_REG_FILE);
>> }
>>
>> -static int dump_linked_remap(char *path, int len, const struct stat *ost,
>> - int lfd, u32 id, struct ns_id *nsid)
>> +static int dump_linked_remap_type(char *path, int len, int lfd, u32 id, struct ns_id *nsid, RemapType remap_type, bool unique)
>> {
>> u32 lid;
>> RemapFilePathEntry rpe = REMAP_FILE_PATH_ENTRY__INIT;
>>
>> - if (create_link_remap(path, len, lfd, &lid, nsid))
>> - return -1;
>> + if (!find_link_remap(path, nsid, &lid)) {
>> + pr_debug("Link remap for %s already exists with id %x\n",
>> + path, lid);
>> + if (unique)
>> + return 0;
>> + } else if (create_link_remap(path, len, lfd, &lid, nsid))
>> + return -1;
>>
>> rpe.orig_id = id;
>> rpe.remap_id = lid;
>> + rpe.has_remap_type = true;
>> + rpe.remap_type = remap_type;
>>
>> return pb_write_one(img_from_set(glob_imgset, CR_FD_REMAP_FPATH),
>> &rpe, PB_REMAP_FPATH);
>> }
>>
>> +static int dump_linked_remap(char *path, int len, const struct stat *ost,
>> + int lfd, u32 id, struct ns_id *nsid)
>> +{
>> + return dump_linked_remap_type(path, len, lfd, id, nsid, REMAP_TYPE__LINKED, false);
>> +}
>> +
>> static pid_t *dead_pids;
>> static int n_dead_pids;
>>
>>
>> _______________________________________________
>> CRIU mailing list
>> CRIU at openvz.org
>> https://lists.openvz.org/mailman/listinfo/criu
>> .
>>