| Message ID | 20241117213206.1636438-2-cel@kernel.org (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Improve simple directory offset wrap behavior | expand |
On Sun, 2024-11-17 at 16:32 -0500, cel@kernel.org wrote: > 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+ > 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); Reviewed-by: Jeff Layton <jlayton@kernel.org>
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);