summaryrefslogtreecommitdiff
path: root/fs/namei.c
diff options
context:
space:
mode:
authorDavid Howells <dhowells@redhat.com>2021-11-18 08:58:08 +0000
committerDavid Howells <dhowells@redhat.com>2022-01-07 13:41:32 +0000
commit1bd9c4e4f0494915b2391f373d25096579f835ff (patch)
tree270de5e2b24d809bffe697572c4410e6f05641b9 /fs/namei.c
parent80f94f29f677d32a1edabc055acfe91c00803592 (diff)
vfs, cachefiles: Mark a backing file in use with an inode flag
Use an inode flag, S_KERNEL_FILE, to mark that a backing file is in use by the kernel to prevent cachefiles or other kernel services from interfering with that file. Alter rmdir to reject attempts to remove a directory marked with this flag. This is used by cachefiles to prevent cachefilesd from removing them. Using S_SWAPFILE instead isn't really viable as that has other effects in the I/O paths. Changes ======= ver #3: - Check for the object pointer being NULL in the tracepoints rather than the caller. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> cc: linux-cachefs@redhat.com Link: https://lore.kernel.org/r/163819630256.215744.4815885535039369574.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/163906931596.143852.8642051223094013028.stgit@warthog.procyon.org.uk/ # v2 Link: https://lore.kernel.org/r/163967141000.1823006.12920680657559677789.stgit@warthog.procyon.org.uk/ # v3 Link: https://lore.kernel.org/r/164021541207.640689.564689725898537127.stgit@warthog.procyon.org.uk/ # v4
Diffstat (limited to 'fs/namei.c')
-rw-r--r--fs/namei.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/namei.c b/fs/namei.c
index 1f9d2187c765..d81f04f8d818 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3958,7 +3958,8 @@ int vfs_rmdir(struct user_namespace *mnt_userns, struct inode *dir,
inode_lock(dentry->d_inode);
error = -EBUSY;
- if (is_local_mountpoint(dentry))
+ if (is_local_mountpoint(dentry) ||
+ (dentry->d_inode->i_flags & S_KERNEL_FILE))
goto out;
error = security_inode_rmdir(dir, dentry);