| Message ID | 1377246883-28772-1-git-send-email-sbehrens@giantdisaster.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On fri, 23 Aug 2013 10:34:42 +0200, Stefan Behrens wrote: > Mitch Harder noticed that the patch 3c64a1a mentioned in the subject > line was causing a kernel BUG() on snapshot deletion. > > The patch was wrong. It did not handle cached roots correctly. The > check for root_refs == 0 was removed everywhere where > btrfs_read_fs_root_no_name() had been used to retrieve the root, > because this check was already dealt with in > btrfs_read_fs_root_no_name(). But in the case when the root was > found in the cache, there was no such check. > > This patch adds the missing check in the case where the root is > found in the cache. > > Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org> > Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> > --- > fs/btrfs/disk-io.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 43ec3c6..7078554 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -1583,8 +1583,11 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, > ERR_PTR(-ENOENT); > again: > root = btrfs_lookup_fs_root(fs_info, location->objectid); > - if (root) > + if (root) { > + if (btrfs_root_refs(&root->root_item) == 0) > + return ERR_PTR(-ENOENT); > return root; > + } It seems good to me. Reviewed-by: Miao Xie <miaox@cn.fujitsu.com> > > root = btrfs_read_fs_root(fs_info->tree_root, location); > if (IS_ERR(root)) > -- 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
On Fri, Aug 23, 2013 at 4:03 AM, Miao Xie <miaox@cn.fujitsu.com> wrote: > On fri, 23 Aug 2013 10:34:42 +0200, Stefan Behrens wrote: >> Mitch Harder noticed that the patch 3c64a1a mentioned in the subject >> line was causing a kernel BUG() on snapshot deletion. >> >> The patch was wrong. It did not handle cached roots correctly. The >> check for root_refs == 0 was removed everywhere where >> btrfs_read_fs_root_no_name() had been used to retrieve the root, >> because this check was already dealt with in >> btrfs_read_fs_root_no_name(). But in the case when the root was >> found in the cache, there was no such check. >> >> This patch adds the missing check in the case where the root is >> found in the cache. >> >> Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org> >> Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> >> --- >> fs/btrfs/disk-io.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c >> index 43ec3c6..7078554 100644 >> --- a/fs/btrfs/disk-io.c >> +++ b/fs/btrfs/disk-io.c >> @@ -1583,8 +1583,11 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, >> ERR_PTR(-ENOENT); >> again: >> root = btrfs_lookup_fs_root(fs_info, location->objectid); >> - if (root) >> + if (root) { >> + if (btrfs_root_refs(&root->root_item) == 0) >> + return ERR_PTR(-ENOENT); >> return root; >> + } > > It seems good to me. > > Reviewed-by: Miao Xie <miaox@cn.fujitsu.com> > >> >> root = btrfs_read_fs_root(fs_info->tree_root, location); >> if (IS_ERR(root)) >> Tested-by: Mitch Harder <mitch.harder@sabayonlinux.org> -- 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/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 43ec3c6..7078554 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -1583,8 +1583,11 @@ struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info, ERR_PTR(-ENOENT); again: root = btrfs_lookup_fs_root(fs_info, location->objectid); - if (root) + if (root) { + if (btrfs_root_refs(&root->root_item) == 0) + return ERR_PTR(-ENOENT); return root; + } root = btrfs_read_fs_root(fs_info->tree_root, location); if (IS_ERR(root))
Mitch Harder noticed that the patch 3c64a1a mentioned in the subject line was causing a kernel BUG() on snapshot deletion. The patch was wrong. It did not handle cached roots correctly. The check for root_refs == 0 was removed everywhere where btrfs_read_fs_root_no_name() had been used to retrieve the root, because this check was already dealt with in btrfs_read_fs_root_no_name(). But in the case when the root was found in the cache, there was no such check. This patch adds the missing check in the case where the root is found in the cache. Reported-by: Mitch Harder <mitch.harder@sabayonlinux.org> Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de> --- fs/btrfs/disk-io.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)