Hi Jan,
I was giving a look to the function scrub_fs_info( ), and to me it seems
that could be a potential file handle leaking problem.
In fact:
static int scrub_fs_info(int fd, char *path,
struct btrfs_ioctl_fs_info_args *fi_args,
struct btrfs_ioctl_dev_info_args **di_ret)
{
[...]
ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args);
if (ret && errno == EINVAL) {
/* path is no mounted btrfs. try if it's a device */
[...]
close(fd); <--- Here the
file handle is
closed
fd = open_file_or_dir(mp); <--- then it is
re-opened
if (fd < 0)
return -errno;
} else if (ret) {
return -errno;
}
[...]
But in the rest of the function:
a) the file handle is not closed
b) the (new) file handle isn't returned
The function "scrub_fs_info()" is called from the functions
1) cmd_scrub_status(), which doesn't use the file handle after the call
to the cmd_scrub_status() [except for a close()]. So no problem at all.
2) scrub_start(), which uses the file handle after the call to the
cmd_scrub_status() functions.
My suggestions is to change scrub_fs_info() to accept only the path.
Then it open (and closes) its own (and private) the file descriptor.
Instead scrub_start(), opens a file descriptor after the call to the
scrub_fs_info() function.
What do you think ?
BR
G.Baroncelli
You can pull the patch below from
http://cassiopea.homelinux.net/git/btrfs-progs-unstable.git
branch
fd-leaking
-----
diff --git a/cmds-scrub.c b/cmds-scrub.c
index c4503f4..486768c 100644
--- a/cmds-scrub.c
+++ b/cmds-scrub.c
@@ -979,19 +979,26 @@ static int scrub_device_info(int fd, u64 devid,
return ret ? -errno : 0;
}
-static int scrub_fs_info(int fd, char *path,
+static int scrub_fs_info( char *path,
struct btrfs_ioctl_fs_info_args *fi_args,
struct btrfs_ioctl_dev_info_args **di_ret)
{
int ret = 0;
int ndevs = 0;
int i = 1;
+ int fd;
struct btrfs_fs_devices *fs_devices_mnt = NULL;
struct btrfs_ioctl_dev_info_args *di_args;
char mp[BTRFS_PATH_NAME_MAX + 1];
memset(fi_args, 0, sizeof(*fi_args));
+ fd = open_file_or_dir(path);
+ if (fd < 0) {
+ fprintf(stderr, "ERROR: can't access to '%s'\n", path);
+ return -1;
+ }
+
ret = ioctl(fd, BTRFS_IOC_FS_INFO, fi_args);
if (ret && errno == EINVAL) {
/* path is no mounted btrfs. try if it's a device */
@@ -1010,28 +1017,36 @@ static int scrub_fs_info(int fd, char *path,
if (fd < 0)
return -errno;
} else if (ret) {
+ close(fd);
return -errno;
}
- if (!fi_args->num_devices)
+ if (!fi_args->num_devices){
+ close(fd);
return 0;
+ }
di_args = *di_ret = malloc(fi_args->num_devices * sizeof(*di_args));
- if (!di_args)
+ if (!di_args){
+ close(fd);
return -errno;
+ }
for (; i <= fi_args->max_id; ++i) {
BUG_ON(ndevs >= fi_args->num_devices);
ret = scrub_device_info(fd, i, &di_args[ndevs]);
if (ret == -ENODEV)
continue;
- if (ret)
+ if (ret){
+ close(fd);
return ret;
+ }
++ndevs;
}
BUG_ON(ndevs == 0);
+ close(fd);
return 0;
}
@@ -1155,7 +1170,7 @@ static int scrub_start(int argc, char **argv, int
resume)
return 12;
}
- ret = scrub_fs_info(fdmnt, path, &fi_args, &di_args);
+ ret = scrub_fs_info(path, &fi_args, &di_args);
if (ret) {
ERR(!do_quiet, "ERROR: getting dev info for scrub failed: "
"%s\n", strerror(-ret));
@@ -1586,7 +1601,6 @@ static int cmd_scrub_status(int argc, char **argv)
.sun_family = AF_UNIX,
};
int ret;
- int fdmnt;
int i;
int print_raw = 0;
int do_stats_per_dev = 0;
@@ -1615,13 +1629,7 @@ static int cmd_scrub_status(int argc, char **argv)
path = argv[optind];
- fdmnt = open_file_or_dir(path);
- if (fdmnt < 0) {
- fprintf(stderr, "ERROR: can't access to '%s'\n", path);
- return 12;
- }
-
- ret = scrub_fs_info(fdmnt, path, &fi_args, &di_args);
+ ret = scrub_fs_info(path, &fi_args, &di_args);
if (ret) {
fprintf(stderr, "ERROR: getting dev info for scrub failed: "
"%s\n", strerror(-ret));
@@ -1698,7 +1706,6 @@ static int cmd_scrub_status(int argc, char **argv)
out:
free_history(past_scrubs);
free(di_args);
- close(fdmnt);
if (fdres > -1)
close(fdres);
--
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