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containerfs: copyup uses a temporary file in the workingdir

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Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
This commit is contained in:
Giuseppe Scrivano 2018-07-06 11:28:18 +02:00
parent 5ec6b893d3
commit 3b7a5a79af
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GPG Key ID: E4730F97F60286ED
1 changed files with 17 additions and 5 deletions
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22
main.c
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@ -148,6 +148,13 @@ lo_data (fuse_req_t req)
return (struct lo_data *) fuse_req_userdata (req); return (struct lo_data *) fuse_req_userdata (req);
} }
static unsigned long
get_next_wd_counter ()
{
static unsigned long counter = 1;
return counter++;
}
static struct lo_mapping * static struct lo_mapping *
read_mappings (const char *str) read_mappings (const char *str)
{ {
@ -280,9 +287,8 @@ hide_node (struct lo_data *lo, struct lo_node *node, bool unlink_src)
{ {
char dest[PATH_MAX]; char dest[PATH_MAX];
char *newpath; char *newpath;
static unsigned long counter = 1;
asprintf (&newpath, "%lu", counter++); asprintf (&newpath, "%lu", get_next_wd_counter ());
if (newpath == NULL) if (newpath == NULL)
{ {
unlink (dest); unlink (dest);
@ -1242,7 +1248,7 @@ copyup (struct lo_data *lo, struct lo_node *node)
char *buf = NULL; char *buf = NULL;
struct timespec times[2]; struct timespec times[2];
ssize_t xattr_len; ssize_t xattr_len;
char wd_tmp_file_name[32];
if (node->parent) if (node->parent)
{ {
@ -1251,6 +1257,8 @@ copyup (struct lo_data *lo, struct lo_node *node)
return ret; return ret;
} }
sprintf (wd_tmp_file_name, "%lu", get_next_wd_counter ());
if (fstatat (node_dirfd (node), node->path, &st, AT_SYMLINK_NOFOLLOW) < 0) if (fstatat (node_dirfd (node), node->path, &st, AT_SYMLINK_NOFOLLOW) < 0)
goto exit; goto exit;
@ -1287,7 +1295,7 @@ copyup (struct lo_data *lo, struct lo_node *node)
if (sfd < 0) if (sfd < 0)
goto exit; goto exit;
dfd = openat (get_upper_layer (lo)->fd, node->path, O_CREAT|O_WRONLY, st.st_mode); dfd = openat (lo->workdir_fd, wd_tmp_file_name, O_CREAT|O_WRONLY, st.st_mode);
if (dfd < 0) if (dfd < 0)
goto exit; goto exit;
@ -1346,6 +1354,10 @@ copyup (struct lo_data *lo, struct lo_node *node)
} }
} }
/* Finally, move the file to its destination. */
ret = renameat (lo->workdir_fd, wd_tmp_file_name, get_upper_layer (lo)->fd, node->path);
if (ret < 0)
goto exit;
success: success:
ret = 0; ret = 0;
@ -1360,7 +1372,7 @@ copyup (struct lo_data *lo, struct lo_node *node)
if (dfd >= 0) if (dfd >= 0)
close (dfd); close (dfd);
if (ret < 0) if (ret < 0)
unlinkat (get_upper_layer (lo)->fd, node->path, 0); unlinkat (lo->workdir_fd, wd_tmp_file_name, 0);
errno = saved_errno; errno = saved_errno;
return ret; return ret;