diff options
| author | David Howells <dhowells@redhat.com> | 2026-06-22 10:08:39 +0100 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2026-07-01 15:26:19 +0200 |
| commit | 81e985b4c3a6cbcc443fcdcd3ebda7fcc845d459 (patch) | |
| tree | 85e393aec7d01ffff4c8429a3c62027b5a1a45db | |
| parent | 733a984a4ee7345325e47efb505eebfe67b299bc (diff) | |
afs: Remove setting of AS_RELEASE_ALWAYS for symlinks and mountpoints
Regular AFS files correctly use afs_file_aops which have release_folio
set as netfs_release_folio, so AS_RELEASE_ALWAYS is valid for them
when fscache is enabled (set via afs_vnode_set_cache()).
Symlinks and mountpoints in AFS use afs_dir_aops, which does not provide
a release_folio callback. However, afs_apply_status() unconditionally
calls mapping_set_release_always() for these.
In such case when memory management code attempts to release folios,
filemap_release_folio() checks folio_needs_release() which
returns true due to AS_RELEASE_ALWAYS being set. Since there is no
release_folio callback, it falls through to try_to_free_buffers(),
which at present expects buffer_heads to be not null. For symlinks
and mountpoints without buffer_heads, this causes pointer dereference.
[dh: Added more bits that were missed]
Fixes: eae9e78951bb ("afs: Use netfslib for symlinks, allowing them to be cached")
Signed-off-by: Deepakkumar Karn <dkarn@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/20260622090856.2746629-6-dhowells@redhat.com
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
| -rw-r--r-- | fs/afs/inode.c | 7 | ||||
| -rw-r--r-- | fs/afs/internal.h | 2 |
2 files changed, 3 insertions, 6 deletions
diff --git a/fs/afs/inode.c b/fs/afs/inode.c index a88995629d72..54ac6ec21daf 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -52,9 +52,9 @@ static noinline void dump_vnode(struct afs_vnode *vnode, struct afs_vnode *paren /* * Set parameters for the netfs library */ -static void afs_set_netfs_context(struct afs_vnode *vnode) +static void afs_set_netfs_context(struct afs_vnode *vnode, bool is_file) { - netfs_inode_init(&vnode->netfs, &afs_req_ops, true); + netfs_inode_init(&vnode->netfs, &afs_req_ops, is_file); } /* @@ -126,7 +126,6 @@ static int afs_inode_init_from_status(struct afs_operation *op, } inode->i_mapping->a_ops = &afs_symlink_aops; inode_nohighmem(inode); - mapping_set_release_always(inode->i_mapping); break; default: dump_vnode(vnode, op->file[0].vnode != vnode ? op->file[0].vnode : NULL); @@ -136,7 +135,7 @@ static int afs_inode_init_from_status(struct afs_operation *op, i_size_write(inode, status->size); inode_set_bytes(inode, status->size); - afs_set_netfs_context(vnode); + afs_set_netfs_context(vnode, status->type == AFS_FTYPE_FILE); vnode->invalid_before = status->data_version; trace_afs_set_dv(vnode, status->data_version); diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 0b72a8566299..785c646856d7 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -750,8 +750,6 @@ static inline void afs_vnode_set_cache(struct afs_vnode *vnode, { #ifdef CONFIG_AFS_FSCACHE vnode->netfs.cache = cookie; - if (cookie) - mapping_set_release_always(vnode->netfs.inode.i_mapping); #endif } |