From: Chuck Lever chuck.lever@oracle.com

Testing shows that the EBUSY error return from mtree_alloc_cyclic() leaks into user space. The ERRORS section of "man creat(2)" says:

EBUSY O_EXCL was specified in flags and pathname refers to a block device that is in use by the system (e.g., it is mounted).

ENOSPC is closer to what applications expect in this situation.

Note that the normal range of simple directory offset values is 2..2^63, so hitting this error is going to be rare to impossible.

Fixes: 6faddda69f62 ("libfs: Add directory operations for stable offsets") Cc: stable@vger.kernel.org # v6.9+ Reviewed-by: Jeff Layton jlayton@kernel.org Reviewed-by: Yang Erkun yangerkun@huawei.com Signed-off-by: Chuck Lever chuck.lever@oracle.com --- fs/libfs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/libfs.c b/fs/libfs.c index 46966fd8bcf9..bf67954b525b 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -288,7 +288,9 @@ int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry)

ret = mtree_alloc_cyclic(&octx->mt, &offset, dentry, DIR_OFFSET_MIN, LONG_MAX, &octx->next_offset, GFP_KERNEL); - if (ret < 0) + if (unlikely(ret == -EBUSY)) + return -ENOSPC; + if (unlikely(ret < 0)) return ret;

offset_set(dentry, offset);