On Tue, Jun 11, 2013 at 12:52:36AM +0100, Filipe David Borba Manana wrote:
> If a device could not be opened in volumes.c:read_one_dev(), a
> btrfs_device instance was allocated and added to the list of
> devices of the fs - however this device instance had its fd,
> name and label fields not initialized. This is problematic in
> disk-io.c:close_all_devices() as it tried to sync, fadvise and
> close the (invalid) fd of the device, and kfree() its name and
> label, which pointed to random memory locations.
>
> Thread 1 (Thread 0x7f0a3d2d1740 (LWP 23585)):
> #0 __GI___libc_free (mem=0xa5a5a5a5a5a5a5a5) at malloc.c:2970
> #1 0x000000000042054b in close_all_devices (fs_info=0x1e92bf0) at disk-io.c:1276
> #2 0x0000000000421dcd in close_ctree (root=<optimized out>) at disk-io.c:1336
> #3 0x0000000000418cfa in cmd_check (argc=<optimized out>, argv=<optimized out>) at cmds-check.c:4171
> #4 0x0000000000403ed4 in main (argc=2, argv=0x7fff9a583d28) at btrfs.c:295
>
> Signed-off-by: Filipe David Borba Manana <fdmanana@xxxxxxxxx>
> ---
> disk-io.c | 4 ++--
> volumes.c | 5 +++--
> 2 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/disk-io.c b/disk-io.c
> index 21b410d..bd9cf4e 100644
> --- a/disk-io.c
> +++ b/disk-io.c
> @@ -1267,12 +1267,12 @@ static int close_all_devices(struct btrfs_fs_info *fs_info)
> while (!list_empty(list)) {
> device = list_entry(list->next, struct btrfs_device, dev_list);
> list_del_init(&device->dev_list);
> - if (device->fd) {
> + if (device->fd >= 0) {
> fsync(device->fd);
> if (posix_fadvise(device->fd, 0, 0, POSIX_FADV_DONTNEED))
> fprintf(stderr, "Warning, could not drop caches\n");
> + close(device->fd);
> }
> - close(device->fd);
> kfree(device->name);
> kfree(device->label);
> kfree(device);
> diff --git a/volumes.c b/volumes.c
> index d6f81f8..061f094 100644
> --- a/volumes.c
> +++ b/volumes.c
> @@ -116,6 +116,7 @@ static int device_list_add(const char *path,
> /* we can safely leave the fs_devices entry around */
> return -ENOMEM;
> }
> + device->fd = -1;
One nit here,
I think it's ok without this since if we get the right device->name, it
means this device is not missing and its fd will be valid.
thanks,
liubo
> device->devid = devid;
> memcpy(device->uuid, disk_super->dev_item.uuid,
> BTRFS_UUID_SIZE);
> @@ -1628,10 +1629,10 @@ static int read_one_dev(struct btrfs_root *root,
> if (!device) {
> printk("warning devid %llu not found already\n",
> (unsigned long long)devid);
> - device = kmalloc(sizeof(*device), GFP_NOFS);
> + device = kzalloc(sizeof(*device), GFP_NOFS);
> if (!device)
> return -ENOMEM;
> - device->total_ios = 0;
> + device->fd = -1;
> list_add(&device->dev_list,
> &root->fs_info->fs_devices->devices);
> }
> --
> 1.7.9.5
>
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