| Message ID | 1440127287-21368-1-git-send-email-quwenruo@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Fri, Aug 21, 2015 at 11:21:26AM +0800, Qu Wenruo wrote: > Offline btrfs tools, like btrfs-image, will infinitely loop when there > is missing device. > > The reason is, for missing device, it's fd will be set to -1, but before > we reading, we only check the fd validation by checking if it's 0. > So in that case, -1 will pass the validation check, and cause pread to > return 0, and loop to read. > > Just change the validation check from "== 0" to "<= 0" to avoid such > problem. > > Reported-by: Timothy Normand Miller <theosib@gmail.com> > Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Applied, thanks. I'll add a test for that. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/btrfs-image.c b/btrfs-image.c index 3684a05..b225325 100644 --- a/btrfs-image.c +++ b/btrfs-image.c @@ -894,7 +894,7 @@ static int read_data_extent(struct metadump_struct *md, device = multi->stripes[0].dev; - if (device->fd == 0) { + if (device->fd <= 0) { fprintf(stderr, "Device we need to read from is not open\n"); free(multi); diff --git a/disk-io.c b/disk-io.c index fdcfd6d..d8ca101 100644 --- a/disk-io.c +++ b/disk-io.c @@ -266,7 +266,7 @@ int read_whole_eb(struct btrfs_fs_info *info, struct extent_buffer *eb, int mirr } device = multi->stripes[0].dev; - if (device->fd == 0) { + if (device->fd <= 0) { kfree(multi); return -EIO; } @@ -385,7 +385,7 @@ int read_extent_data(struct btrfs_root *root, char *data, } device = multi->stripes[0].dev; - if (device->fd == 0) + if (device->fd <= 0) goto err; if (*len > max_len) *len = max_len; diff --git a/extent_io.c b/extent_io.c index 5d49710..07695ef 100644 --- a/extent_io.c +++ b/extent_io.c @@ -714,7 +714,7 @@ int read_data_from_disk(struct btrfs_fs_info *info, void *buf, u64 offset, device = multi->stripes[0].dev; read_len = min(bytes_left, read_len); - if (device->fd == 0) { + if (device->fd <= 0) { kfree(multi); return -EIO; } @@ -790,7 +790,7 @@ int write_data_to_disk(struct btrfs_fs_info *info, void *buf, u64 offset, raid_map = NULL; } else while (dev_nr < multi->num_stripes) { device = multi->stripes[dev_nr].dev; - if (device->fd == 0) { + if (device->fd <= 0) { kfree(multi); return -EIO; }
Offline btrfs tools, like btrfs-image, will infinitely loop when there is missing device. The reason is, for missing device, it's fd will be set to -1, but before we reading, we only check the fd validation by checking if it's 0. So in that case, -1 will pass the validation check, and cause pread to return 0, and loop to read. Just change the validation check from "== 0" to "<= 0" to avoid such problem. Reported-by: Timothy Normand Miller <theosib@gmail.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> --- btrfs-image.c | 2 +- disk-io.c | 4 ++-- extent_io.c | 4 ++-- 3 files changed, 5 insertions(+), 5 deletions(-)