diff options
author | NeilBrown <neilb@suse.de> | 2021-09-28 09:47:57 +1000 |
---|---|---|
committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2022-01-06 14:00:20 -0500 |
commit | 73fbb3fa647bdb5b60469af8101c741ece03a825 (patch) | |
tree | 3bcd719fb8cab07c7571ab8ac0962ed701a8437c /fs/nfs/dir.c | |
parent | b5e7b59c3480f355910f9d2c6ece5857922a5e54 (diff) | |
download | linux-73fbb3fa647bdb5b60469af8101c741ece03a825.tar.bz2 |
NFS: pass cred explicitly for access tests
Storing the 'struct cred *' in nfs_access_entry is problematic.
An active 'cred' can keep a 'struct key *' active, and a quota is
imposed on the number of such keys that a user can maintain.
Cached 'nfs_access_entry' structs have indefinite lifetime, and having
these keep 'struct key's alive imposes on that quota.
So a future patch will remove the ->cred ref from nfs_access_entry.
To prepare, change various functions to not assume there is a 'cred' in
the nfs_access_entry, but to pass the cred around explicitly.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'fs/nfs/dir.c')
-rw-r--r-- | fs/nfs/dir.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 8487a6d69116..a34351ce79a2 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2758,7 +2758,9 @@ int nfs_access_get_cached(struct inode *inode, const struct cred *cred, } EXPORT_SYMBOL_GPL(nfs_access_get_cached); -static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *set) +static void nfs_access_add_rbtree(struct inode *inode, + struct nfs_access_entry *set, + const struct cred *cred) { struct nfs_inode *nfsi = NFS_I(inode); struct rb_root *root_node = &nfsi->access_cache; @@ -2771,7 +2773,7 @@ static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry * while (*p != NULL) { parent = *p; entry = rb_entry(parent, struct nfs_access_entry, rb_node); - cmp = cred_fscmp(set->cred, entry->cred); + cmp = cred_fscmp(cred, entry->cred); if (cmp < 0) p = &parent->rb_left; @@ -2793,13 +2795,14 @@ found: nfs_access_free_entry(entry); } -void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) +void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set, + const struct cred *cred) { struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); if (cache == NULL) return; RB_CLEAR_NODE(&cache->rb_node); - cache->cred = get_cred(set->cred); + cache->cred = get_cred(cred); cache->mask = set->mask; /* The above field assignments must be visible @@ -2807,7 +2810,7 @@ void nfs_access_add_cache(struct inode *inode, struct nfs_access_entry *set) * use rcu_assign_pointer, so just force the memory barrier. */ smp_wmb(); - nfs_access_add_rbtree(inode, cache); + nfs_access_add_rbtree(inode, cache, cred); /* Update accounting */ smp_mb__before_atomic(); @@ -2893,7 +2896,7 @@ static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask) else cache.mask |= NFS_ACCESS_EXECUTE; cache.cred = cred; - status = NFS_PROTO(inode)->access(inode, &cache); + status = NFS_PROTO(inode)->access(inode, &cache, cred); if (status != 0) { if (status == -ESTALE) { if (!S_ISDIR(inode->i_mode)) @@ -2903,7 +2906,7 @@ static int nfs_do_access(struct inode *inode, const struct cred *cred, int mask) } goto out; } - nfs_access_add_cache(inode, &cache); + nfs_access_add_cache(inode, &cache, cred); out_cached: cache_mask = nfs_access_calc_mask(cache.mask, inode->i_mode); if ((mask & ~cache_mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) != 0) |