diff options
| -rw-r--r-- | fs/nfs/delegation.c | 6 | ||||
| -rw-r--r-- | fs/nfs/dir.c | 105 | ||||
| -rw-r--r-- | fs/nfs/inode.c | 1 | ||||
| -rw-r--r-- | include/linux/nfs_fs.h | 26 |
4 files changed, 115 insertions, 23 deletions
diff --git a/fs/nfs/delegation.c b/fs/nfs/delegation.c index 4a841071d8a7..d856326836a2 100644 --- a/fs/nfs/delegation.c +++ b/fs/nfs/delegation.c @@ -42,6 +42,8 @@ static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation) if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) { delegation->stateid.type = NFS4_INVALID_STATEID_TYPE; atomic_long_dec(&nfs_active_delegations); + if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) + nfs_clear_verifier_delegated(delegation->inode); } } @@ -276,6 +278,8 @@ nfs_start_delegation_return_locked(struct nfs_inode *nfsi) if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) ret = delegation; spin_unlock(&delegation->lock); + if (ret) + nfs_clear_verifier_delegated(&nfsi->vfs_inode); out: return ret; } @@ -689,6 +693,8 @@ void nfs4_inode_return_delegation_on_close(struct inode *inode) ret = delegation; } spin_unlock(&delegation->lock); + if (ret) + nfs_clear_verifier_delegated(inode); } out: rcu_read_unlock(); diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index b4e7558e42ab..193d6fb363b7 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -986,14 +986,113 @@ static int nfs_fsync_dir(struct file *filp, loff_t start, loff_t end, * full lookup on all child dentries of 'dir' whenever a change occurs * on the server that might have invalidated our dcache. * + * Note that we reserve bit '0' as a tag to let us know when a dentry + * was revalidated while holding a delegation on its inode. + * * The caller should be holding dir->i_lock */ void nfs_force_lookup_revalidate(struct inode *dir) { - NFS_I(dir)->cache_change_attribute++; + NFS_I(dir)->cache_change_attribute += 2; } EXPORT_SYMBOL_GPL(nfs_force_lookup_revalidate); +/** + * nfs_verify_change_attribute - Detects NFS remote directory changes + * @dir: pointer to parent directory inode + * @verf: previously saved change attribute + * + * Return "false" if the verifiers doesn't match the change attribute. + * This would usually indicate that the directory contents have changed on + * the server, and that any dentries need revalidating. + */ +static bool nfs_verify_change_attribute(struct inode *dir, unsigned long verf) +{ + return (verf & ~1UL) == nfs_save_change_attribute(dir); +} + +static void nfs_set_verifier_delegated(unsigned long *verf) +{ + *verf |= 1UL; +} + +#if IS_ENABLED(CONFIG_NFS_V4) +static void nfs_unset_verifier_delegated(unsigned long *verf) +{ + *verf &= ~1UL; +} +#endif /* IS_ENABLED(CONFIG_NFS_V4) */ + +static bool nfs_test_verifier_delegated(unsigned long verf) +{ + return verf & 1; +} + +static bool nfs_verifier_is_delegated(struct dentry *dentry) +{ + return nfs_test_verifier_delegated(dentry->d_time); +} + +static void nfs_set_verifier_locked(struct dentry *dentry, unsigned long verf) +{ + struct inode *inode = d_inode(dentry); + + if (!nfs_verifier_is_delegated(dentry) && + !nfs_verify_change_attribute(d_inode(dentry->d_parent), verf)) + goto out; + if (inode && NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) + nfs_set_verifier_delegated(&verf); +out: + dentry->d_time = verf; +} + +/** + * nfs_set_verifier - save a parent directory verifier in the dentry + * @dentry: pointer to dentry + * @verf: verifier to save + * + * Saves the parent directory verifier in @dentry. If the inode has + * a delegation, we also tag the dentry as having been revalidated + * while holding a delegation so that we know we don't have to + * look it up again after a directory change. + */ +void nfs_set_verifier(struct dentry *dentry, unsigned long verf) +{ + + spin_lock(&dentry->d_lock); + nfs_set_verifier_locked(dentry, verf); + spin_unlock(&dentry->d_lock); +} +EXPORT_SYMBOL_GPL(nfs_set_verifier); + +#if IS_ENABLED(CONFIG_NFS_V4) +/** + * nfs_clear_verifier_delegated - clear the dir verifier delegation tag + * @inode: pointer to inode + * + * Iterates through the dentries in the inode alias list and clears + * the tag used to indicate that the dentry has been revalidated + * while holding a delegation. + * This function is intended for use when the delegation is being + * returned or revoked. + */ +void nfs_clear_verifier_delegated(struct inode *inode) +{ + struct dentry *alias; + + if (!inode) + return; + spin_lock(&inode->i_lock); + hlist_for_each_entry(alias, &inode->i_dentry, d_u.d_alias) { + spin_lock(&alias->d_lock); + nfs_unset_verifier_delegated(&alias->d_time); + spin_unlock(&alias->d_lock); + } + spin_unlock(&inode->i_lock); +} +EXPORT_SYMBOL_GPL(nfs_clear_verifier_delegated); +#endif /* IS_ENABLED(CONFIG_NFS_V4) */ + /* * A check for whether or not the parent directory has changed. * In the case it has, we assume that the dentries are untrustworthy @@ -1235,7 +1334,7 @@ nfs_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, goto out_bad; } - if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ)) + if (nfs_verifier_is_delegated(dentry)) return nfs_lookup_revalidate_delegated(dir, dentry, inode); /* Force a full look up iff the parent directory has changed */ @@ -1675,7 +1774,7 @@ nfs4_do_lookup_revalidate(struct inode *dir, struct dentry *dentry, if (inode == NULL) goto full_reval; - if (NFS_PROTO(dir)->have_delegation(inode, FMODE_READ)) + if (nfs_verifier_is_delegated(dentry)) return nfs_lookup_revalidate_delegated(dir, dentry, inode); /* NFS only supports OPEN on regular files */ diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index 1309e6f47f3d..11bf15800ac9 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -2114,6 +2114,7 @@ static void init_once(void *foo) init_rwsem(&nfsi->rmdir_sem); mutex_init(&nfsi->commit_mutex); nfs4_init_once(nfsi); + nfsi->cache_change_attribute = 0; } static int __init nfs_init_inodecache(void) diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index a5f8f03ecd59..5d5b91e54f73 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -337,35 +337,17 @@ static inline int nfs_server_capable(struct inode *inode, int cap) return NFS_SERVER(inode)->caps & cap; } -static inline void nfs_set_verifier(struct dentry * dentry, unsigned long verf) -{ - dentry->d_time = verf; -} - /** * nfs_save_change_attribute - Returns the inode attribute change cookie * @dir - pointer to parent directory inode - * The "change attribute" is updated every time we finish an operation - * that will result in a metadata change on the server. + * The "cache change attribute" is updated when we need to revalidate + * our dentry cache after a directory was seen to change on the server. */ static inline unsigned long nfs_save_change_attribute(struct inode *dir) { return NFS_I(dir)->cache_change_attribute; } -/** - * nfs_verify_change_attribute - Detects NFS remote directory changes - * @dir - pointer to parent directory inode - * @chattr - previously saved change attribute - * Return "false" if the verifiers doesn't match the change attribute. - * This would usually indicate that the directory contents have changed on - * the server, and that any dentries need revalidating. - */ -static inline int nfs_verify_change_attribute(struct inode *dir, unsigned long chattr) -{ - return chattr == NFS_I(dir)->cache_change_attribute; -} - /* * linux/fs/nfs/inode.c */ @@ -495,6 +477,10 @@ extern const struct file_operations nfs_dir_operations; extern const struct dentry_operations nfs_dentry_operations; extern void nfs_force_lookup_revalidate(struct inode *dir); +extern void nfs_set_verifier(struct dentry * dentry, unsigned long verf); +#if IS_ENABLED(CONFIG_NFS_V4) +extern void nfs_clear_verifier_delegated(struct inode *inode); +#endif /* IS_ENABLED(CONFIG_NFS_V4) */ extern struct dentry *nfs_add_or_obtain(struct dentry *dentry, struct nfs_fh *fh, struct nfs_fattr *fattr, struct nfs4_label *label); |