diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index e5869f91b3ab..87289b9a152c 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -417,8 +417,7 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, goto out_cleanup; newdentry = dget(tmpfile ? upper : temp); - ovl_dentry_update(dentry, newdentry); - ovl_inode_update(d_inode(dentry), d_inode(newdentry)); + ovl_inode_update(d_inode(dentry), newdentry); /* Restore timestamps on parent (best effort) */ ovl_set_timestamps(upperdir, pstat); diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 59e0dc9897fb..d0d6292e069a 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -154,12 +154,12 @@ static void ovl_instantiate(struct dentry *dentry, struct inode *inode, struct dentry *newdentry, bool hardlink) { ovl_dentry_version_inc(dentry->d_parent); - ovl_dentry_update(dentry, newdentry); if (!hardlink) { - ovl_inode_update(inode, d_inode(newdentry)); + ovl_inode_update(inode, newdentry); ovl_copyattr(newdentry->d_inode, inode); } else { - WARN_ON(ovl_inode_real(inode, NULL) != d_inode(newdentry)); + WARN_ON(ovl_inode_real(inode) != d_inode(newdentry)); + dput(newdentry); inc_nlink(inode); } d_instantiate(dentry, inode); @@ -1003,7 +1003,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, new_opaque = ovl_dentry_is_opaque(new); err = -ESTALE; - if (ovl_dentry_upper(new)) { + if (d_inode(new) && ovl_dentry_upper(new)) { if (opaquedir) { if (newdentry != opaquedir) goto out_dput; diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 4c30d44905ef..4654c03dd508 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -134,8 +134,8 @@ out: int ovl_permission(struct inode *inode, int mask) { - bool is_upper; - struct inode *realinode = ovl_inode_real(inode, &is_upper); + struct inode *upperinode = ovl_inode_upper(inode); + struct inode *realinode = upperinode ?: ovl_inode_lower(inode); const struct cred *old_cred; int err; @@ -154,7 +154,8 @@ int ovl_permission(struct inode *inode, int mask) return err; old_cred = ovl_override_creds(inode->i_sb); - if (!is_upper && !special_file(realinode->i_mode) && mask & MAY_WRITE) { + if (!upperinode && + !special_file(realinode->i_mode) && mask & MAY_WRITE) { mask &= ~(MAY_WRITE | MAY_APPEND); /* Make sure mounter can read file for copy up later */ mask |= MAY_READ; @@ -286,7 +287,7 @@ ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) struct posix_acl *ovl_get_acl(struct inode *inode, int type) { - struct inode *realinode = ovl_inode_real(inode, NULL); + struct inode *realinode = ovl_inode_real(inode); const struct cred *old_cred; struct posix_acl *acl; @@ -462,17 +463,24 @@ static int ovl_inode_set(struct inode *inode, void *data) return 0; } -struct inode *ovl_get_inode(struct dentry *dentry) +struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry) { - struct dentry *upperdentry = ovl_dentry_upper(dentry); - struct inode *realinode = d_inode(ovl_dentry_real(dentry)); + struct dentry *lowerdentry = ovl_dentry_lower(dentry); + struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL; struct inode *inode; + if (!realinode) + realinode = d_inode(lowerdentry); + if (upperdentry && !d_is_dir(upperdentry)) { inode = iget5_locked(dentry->d_sb, (unsigned long) realinode, ovl_inode_test, ovl_inode_set, realinode); - if (!inode || !(inode->i_state & I_NEW)) + if (!inode) goto out; + if (!(inode->i_state & I_NEW)) { + dput(upperdentry); + goto out; + } set_nlink(inode, realinode->i_nlink); } else { @@ -481,7 +489,7 @@ struct inode *ovl_get_inode(struct dentry *dentry) goto out; } ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev); - ovl_inode_init(inode, dentry); + ovl_inode_init(inode, upperdentry, lowerdentry); if (inode->i_state & I_NEW) unlock_new_inode(inode); out: diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 0072ca5d5dac..1f873e2e8a79 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -359,7 +359,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, return ERR_PTR(-ENAMETOOLONG); old_cred = ovl_override_creds(dentry->d_sb); - upperdir = ovl_upperdentry_dereference(poe); + upperdir = ovl_dentry_upper(dentry->d_parent); if (upperdir) { err = ovl_lookup_layer(upperdir, &d, &upperdentry); if (err) @@ -436,13 +436,12 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, oe->opaque = upperopaque; oe->impure = upperimpure; oe->redirect = upperredirect; - oe->__upperdentry = upperdentry; memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr); dentry->d_fsdata = oe; if (upperdentry || ctr) { err = -ENOMEM; - inode = ovl_get_inode(dentry); + inode = ovl_get_inode(dentry, upperdentry); if (!inode) goto out_free_oe; } @@ -487,7 +486,7 @@ bool ovl_lower_positive(struct dentry *dentry) return oe->opaque; /* Negative upper -> positive lower */ - if (!oe->__upperdentry) + if (!ovl_dentry_upper(dentry)) return true; /* Positive upper -> have to look up lower to see whether it exists */ diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 6e6600ae1d54..83607f883ace 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -189,7 +189,9 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); struct dentry *ovl_dentry_upper(struct dentry *dentry); struct dentry *ovl_dentry_lower(struct dentry *dentry); struct dentry *ovl_dentry_real(struct dentry *dentry); -struct inode *ovl_inode_real(struct inode *inode, bool *is_upper); +struct inode *ovl_inode_upper(struct inode *inode); +struct inode *ovl_inode_lower(struct inode *inode); +struct inode *ovl_inode_real(struct inode *inode); struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry); void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache); bool ovl_dentry_is_opaque(struct dentry *dentry); @@ -199,9 +201,9 @@ void ovl_dentry_set_opaque(struct dentry *dentry); bool ovl_redirect_dir(struct super_block *sb); const char *ovl_dentry_get_redirect(struct dentry *dentry); void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); -void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry); -void ovl_inode_init(struct inode *inode, struct dentry *dentry); -void ovl_inode_update(struct inode *inode, struct inode *upperinode); +void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, + struct dentry *lowerdentry); +void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); void ovl_dentry_version_inc(struct dentry *dentry); u64 ovl_dentry_version_get(struct dentry *dentry); bool ovl_is_whiteout(struct dentry *dentry); @@ -250,7 +252,7 @@ int ovl_update_time(struct inode *inode, struct timespec *ts, int flags); bool ovl_is_private_xattr(const char *name); struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); -struct inode *ovl_get_inode(struct dentry *dentry); +struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry); static inline void ovl_copyattr(struct inode *from, struct inode *to) { to->i_uid = from->i_uid; diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index b8c213891e84..ddd937490f0d 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -36,7 +36,6 @@ struct ovl_fs { /* private information held for every overlayfs dentry */ struct ovl_entry { - struct dentry *__upperdentry; struct ovl_dir_cache *cache; union { struct { @@ -54,14 +53,9 @@ struct ovl_entry { struct ovl_entry *ovl_alloc_entry(unsigned int numlower); -static inline struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe) -{ - return lockless_dereference(oe->__upperdentry); -} - struct ovl_inode { struct inode vfs_inode; - struct inode *upper; + struct dentry *__upperdentry; struct inode *lower; }; @@ -69,3 +63,8 @@ static inline struct ovl_inode *OVL_I(struct inode *inode) { return container_of(inode, struct ovl_inode, vfs_inode); } + +static inline struct dentry *ovl_upperdentry_dereference(struct ovl_inode *oi) +{ + return lockless_dereference(oi->__upperdentry); +} diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index c166c1d76890..1b865716110a 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -41,7 +41,6 @@ static void ovl_dentry_release(struct dentry *dentry) if (oe) { unsigned int i; - dput(oe->__upperdentry); kfree(oe->redirect); for (i = 0; i < oe->numlower; i++) dput(oe->lowerstack[i].dentry); @@ -171,7 +170,7 @@ static struct inode *ovl_alloc_inode(struct super_block *sb) { struct ovl_inode *oi = kmem_cache_alloc(ovl_inode_cachep, GFP_KERNEL); - oi->upper = NULL; + oi->__upperdentry = NULL; oi->lower = NULL; return &oi->vfs_inode; @@ -186,6 +185,10 @@ static void ovl_i_callback(struct rcu_head *head) static void ovl_destroy_inode(struct inode *inode) { + struct ovl_inode *oi = OVL_I(inode); + + dput(oi->__upperdentry); + call_rcu(&inode->i_rcu, ovl_i_callback); } @@ -636,7 +639,7 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler, size_t size, int flags) { struct dentry *workdir = ovl_workdir(dentry); - struct inode *realinode = ovl_inode_real(inode, NULL); + struct inode *realinode = ovl_inode_real(inode); struct posix_acl *acl = NULL; int err; @@ -678,7 +681,7 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler, err = ovl_xattr_set(dentry, handler->name, value, size, flags); if (!err) - ovl_copyattr(ovl_inode_real(inode, NULL), inode); + ovl_copyattr(ovl_inode_real(inode), inode); return err; @@ -1000,7 +1003,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) kfree(lowertmp); if (upperpath.dentry) { - oe->__upperdentry = upperpath.dentry; oe->impure = ovl_is_impuredir(upperpath.dentry); } for (i = 0; i < numlower; i++) { @@ -1011,7 +1013,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) root_dentry->d_fsdata = oe; - ovl_inode_init(d_inode(root_dentry), root_dentry); + ovl_inode_init(d_inode(root_dentry), upperpath.dentry, + ovl_dentry_lower(root_dentry)); sb->s_root = root_dentry; diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index fc7b1447435b..e5d9e8daa55c 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -78,7 +78,7 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry) struct ovl_entry *oe = dentry->d_fsdata; enum ovl_path_type type = 0; - if (oe->__upperdentry) { + if (ovl_dentry_upper(dentry)) { type = __OVL_PATH_UPPER; /* @@ -99,10 +99,9 @@ enum ovl_path_type ovl_path_type(struct dentry *dentry) void ovl_path_upper(struct dentry *dentry, struct path *path) { struct ovl_fs *ofs = dentry->d_sb->s_fs_info; - struct ovl_entry *oe = dentry->d_fsdata; path->mnt = ofs->upper_mnt; - path->dentry = ovl_upperdentry_dereference(oe); + path->dentry = ovl_dentry_upper(dentry); } void ovl_path_lower(struct dentry *dentry, struct path *path) @@ -126,51 +125,39 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) struct dentry *ovl_dentry_upper(struct dentry *dentry) { - struct ovl_entry *oe = dentry->d_fsdata; - - return ovl_upperdentry_dereference(oe); -} - -static struct dentry *__ovl_dentry_lower(struct ovl_entry *oe) -{ - return oe->numlower ? oe->lowerstack[0].dentry : NULL; + return ovl_upperdentry_dereference(OVL_I(d_inode(dentry))); } struct dentry *ovl_dentry_lower(struct dentry *dentry) { struct ovl_entry *oe = dentry->d_fsdata; - return __ovl_dentry_lower(oe); + return oe->numlower ? oe->lowerstack[0].dentry : NULL; } struct dentry *ovl_dentry_real(struct dentry *dentry) { - struct ovl_entry *oe = dentry->d_fsdata; - struct dentry *realdentry; - - realdentry = ovl_upperdentry_dereference(oe); - if (!realdentry) - realdentry = __ovl_dentry_lower(oe); - - return realdentry; + return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry); } -struct inode *ovl_inode_real(struct inode *inode, bool *is_upper) +struct inode *ovl_inode_upper(struct inode *inode) { - struct inode *realinode = lockless_dereference(OVL_I(inode)->upper); - bool isup = false; + struct dentry *upperdentry = ovl_upperdentry_dereference(OVL_I(inode)); - if (!realinode) - realinode = OVL_I(inode)->lower; - else - isup = true; - - if (is_upper) - *is_upper = isup; - - return realinode; + return upperdentry ? d_inode(upperdentry) : NULL; } +struct inode *ovl_inode_lower(struct inode *inode) +{ + return OVL_I(inode)->lower; +} + +struct inode *ovl_inode_real(struct inode *inode) +{ + return ovl_inode_upper(inode) ?: ovl_inode_lower(inode); +} + + struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry) { struct ovl_entry *oe = dentry->d_fsdata; @@ -232,42 +219,30 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect) oe->redirect = redirect; } -void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry) +void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, + struct dentry *lowerdentry) { - struct ovl_entry *oe = dentry->d_fsdata; + if (upperdentry) + OVL_I(inode)->__upperdentry = upperdentry; + if (lowerdentry) + OVL_I(inode)->lower = d_inode(lowerdentry); - WARN_ON(!inode_is_locked(upperdentry->d_parent->d_inode)); - WARN_ON(oe->__upperdentry); - /* - * Make sure upperdentry is consistent before making it visible to - * ovl_upperdentry_dereference(). - */ - smp_wmb(); - oe->__upperdentry = upperdentry; + ovl_copyattr(d_inode(upperdentry ?: lowerdentry), inode); } -void ovl_inode_init(struct inode *inode, struct dentry *dentry) +void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) { - struct inode *realinode = d_inode(ovl_dentry_real(dentry)); + struct inode *upperinode = d_inode(upperdentry); - if (ovl_dentry_upper(dentry)) - OVL_I(inode)->upper = realinode; - else - OVL_I(inode)->lower = realinode; - - ovl_copyattr(realinode, inode); -} - -void ovl_inode_update(struct inode *inode, struct inode *upperinode) -{ - WARN_ON(!upperinode); WARN_ON(!inode_unhashed(inode)); + WARN_ON(!inode_is_locked(upperdentry->d_parent->d_inode)); + WARN_ON(OVL_I(inode)->__upperdentry); + /* - * Make sure upperinode is consistent before making it visible to - * ovl_inode_real(); + * Make sure upperdentry is consistent before making it visible */ smp_wmb(); - OVL_I(inode)->upper = upperinode; + OVL_I(inode)->__upperdentry = upperdentry; if (!S_ISDIR(upperinode->i_mode)) { inode->i_private = upperinode; __insert_inode_hash(inode, (unsigned long) upperinode); @@ -311,7 +286,7 @@ int ovl_copy_up_start(struct dentry *dentry) spin_lock(&ofs->copyup_wq.lock); err = wait_event_interruptible_locked(ofs->copyup_wq, !oe->copying); if (!err) { - if (oe->__upperdentry) + if (ovl_dentry_upper(dentry)) err = 1; /* Already copied up */ else oe->copying = true;