[CRIU] [PATCH 08/16] files-ids: generate id-s accoding with mnt_id, st->st_dev and st->st_ino

[Pavel Emelyanov]

On 04/09/2014 03:35 AM, Andrey Vagin wrote:
> One device can be mounted a few times, so files are identical only,
> if they have the same mnt_id.

I see no changes in fdid generation, only it the caching.

> Signed-off-by: Andrey Vagin <avagin at openvz.org>
> ---
>  cr-dump.c          |  8 ++++----
>  file-ids.c         | 32 +++++++++++++++++++-------------
>  files.c            |  2 +-
>  include/file-ids.h |  5 +++--
>  4 files changed, 27 insertions(+), 20 deletions(-)
> 
> diff --git a/cr-dump.c b/cr-dump.c
> index 075a75f..ca85ca8 100644
> --- a/cr-dump.c
> +++ b/cr-dump.c
> @@ -268,7 +268,7 @@ static int dump_task_exe_link(pid_t pid, MmEntry *mm)
>  	if (get_fd_mntid(fd, &params.mnt_id))
>  		return -1;
>  
> -	if (fd_id_generate_special(&params.stat, &mm->exe_file_id)) {
> +	if (fd_id_generate_special(&params, &mm->exe_file_id)) {
>  		ret = dump_one_reg_file(fd, mm->exe_file_id, &params);
>  	}
>  
> @@ -297,7 +297,7 @@ static int dump_task_fs(pid_t pid, struct parasite_dump_misc *misc, struct cr_fd
>  	if (get_fd_mntid(fd, &p.mnt_id))
>  		return -1;
>  
> -	if (fd_id_generate_special(&p.stat, &fe.cwd_id)) {
> +	if (fd_id_generate_special(&p, &fe.cwd_id)) {
>  		ret = dump_one_reg_file(fd, fe.cwd_id, &p);
>  		if (ret < 0)
>  			return ret;
> @@ -318,7 +318,7 @@ static int dump_task_fs(pid_t pid, struct parasite_dump_misc *misc, struct cr_fd
>  	if (get_fd_mntid(fd, &p.mnt_id))
>  		return -1;
>  
> -	if (fd_id_generate_special(&p.stat, &fe.root_id)) {
> +	if (fd_id_generate_special(&p, &fe.root_id)) {
>  		ret = dump_one_reg_file(fd, fe.root_id, &p);
>  		if (ret < 0)
>  			return ret;
> @@ -372,7 +372,7 @@ static int dump_filemap(pid_t pid, struct vma_area *vma_area,
>  
>  	/* Flags will be set during restore in get_filemap_fd() */
>  
> -	if (fd_id_generate_special(&p.stat, &id)) {
> +	if (fd_id_generate_special(&p, &id)) {
>  		ret = dump_one_reg_file(vma_area->vm_file_fd, id, &p);
>  	}
>  
> diff --git a/file-ids.c b/file-ids.c
> index 30f1bbc..3226d15 100644
> --- a/file-ids.c
> +++ b/file-ids.c
> @@ -18,6 +18,7 @@
>  #include "image.h"
>  #include "util.h"
>  #include "irmap.h"
> +#include "files.h"
>  
>  static DECLARE_KCMP_TREE(fd_tree, KCMP_FILE);
>  
> @@ -36,6 +37,7 @@ static inline int fdid_hashfn(unsigned int s_dev, unsigned long i_ino)
>  }
>  
>  struct fd_id {
> +	int mnt_id;
>  	unsigned int dev;
>  	unsigned long ino;
>  	u32 id;
> @@ -44,41 +46,45 @@ struct fd_id {
>  
>  static struct fd_id *fd_id_cache[FDID_SIZE];
>  
> -static void fd_id_cache_one(u32 id, struct stat *st)
> +static void fd_id_cache_one(u32 id, struct fd_parms *p)
>  {
>  	struct fd_id *fi;
>  	unsigned hv;
>  
>  	fi = xmalloc(sizeof(*fi));
>  	if (fi) {
> -		fi->dev = st->st_dev;
> -		fi->ino = st->st_ino;
> +		fi->dev = p->stat.st_dev;
> +		fi->ino = p->stat.st_ino;
> +		fi->mnt_id = p->mnt_id;
>  		fi->id = id;
>  
> -		hv = fdid_hashfn(st->st_dev, st->st_ino);
> +		hv = fdid_hashfn(p->stat.st_dev, p->stat.st_ino);
>  		fi->n = fd_id_cache[hv];
>  		fd_id_cache[hv] = fi;
>  	}
>  }
>  
> -static struct fd_id *fd_id_cache_lookup(struct stat *st)
> +static struct fd_id *fd_id_cache_lookup(struct fd_parms *p)
>  {
> +	struct stat *st = &p->stat;
>  	struct fd_id *fi;
>  
>  	for (fi = fd_id_cache[fdid_hashfn(st->st_dev, st->st_ino)];
>  			fi; fi = fi->n)
> -		if (fi->dev == st->st_dev && fi->ino == st->st_ino)
> +		if (fi->dev == st->st_dev &&
> +		    fi->ino == st->st_ino &&
> +		    fi->mnt_id == p->mnt_id)
>  			return fi;
>  
>  	return NULL;
>  }
>  
> -int fd_id_generate_special(struct stat *st, u32 *id)
> +int fd_id_generate_special(struct fd_parms *p, u32 *id)
>  {
> -	if (st) {
> +	if (p) {
>  		struct fd_id *fi;
>  
> -		fi = fd_id_cache_lookup(st);
> +		fi = fd_id_cache_lookup(p);
>  		if (fi) {
>  			*id = fi->id;
>  			return 0;
> @@ -86,12 +92,12 @@ int fd_id_generate_special(struct stat *st, u32 *id)
>  	}
>  
>  	*id = fd_tree.subid++;
> -	if (st)
> -		fd_id_cache_one(*id, st);
> +	if (p)
> +		fd_id_cache_one(*id, p);
>  	return 1;
>  }
>  
> -int fd_id_generate(pid_t pid, FdinfoEntry *fe, struct stat *st)
> +int fd_id_generate(pid_t pid, FdinfoEntry *fe, struct fd_parms *p)
>  {
>  	u32 id;
>  	struct kid_elem e;
> @@ -106,7 +112,7 @@ int fd_id_generate(pid_t pid, FdinfoEntry *fe, struct stat *st)
>  		return -ENOMEM;
>  
>  	if (new_id)
> -		fd_id_cache_one(id, st);
> +		fd_id_cache_one(id, p);
>  
>  	fe->id = id;
>  	return new_id;
> diff --git a/files.c b/files.c
> index cfbbb4b..f2b7435 100644
> --- a/files.c
> +++ b/files.c
> @@ -171,7 +171,7 @@ int do_dump_gen_file(struct fd_parms *p, int lfd,
>  	e.fd	= p->fd;
>  	e.flags = p->fd_flags;
>  
> -	ret = fd_id_generate(p->pid, &e, &p->stat);
> +	ret = fd_id_generate(p->pid, &e, p);
>  	if (ret == 1) /* new ID generated */
>  		ret = ops->dump(lfd, e.id, p);
>  
> diff --git a/include/file-ids.h b/include/file-ids.h
> index 28434f3..6323d98 100644
> --- a/include/file-ids.h
> +++ b/include/file-ids.h
> @@ -13,8 +13,9 @@
>  struct fdinfo_entry;
>  struct stat;
>  
> -extern int fd_id_generate(pid_t pid, FdinfoEntry *fe, struct stat *st);
> -extern int fd_id_generate_special(struct stat *, u32 *id);
> +struct fd_parms;
> +extern int fd_id_generate(pid_t pid, FdinfoEntry *fe, struct fd_parms *p);
> +extern int fd_id_generate_special(struct fd_parms *p, u32 *id);
>  extern void fd_id_show_tree(void);
>  
>  #endif /* __CR_FILE_IDS_H__ */
>