diff options
| -rw-r--r-- | fs/overlayfs/dir.c | 59 | ||||
| -rw-r--r-- | fs/overlayfs/inode.c | 12 | ||||
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 1 |
3 files changed, 60 insertions, 12 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index e8c7df070fed..f480b1a2cd2e 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -229,24 +229,54 @@ static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) return ovl_set_opaque_xerr(dentry, upperdentry, -EIO); } -/* Common operations required to be done after creation of file on upper */ -static void ovl_instantiate(struct dentry *dentry, struct inode *inode, - struct dentry *newdentry, bool hardlink) +/* + * Common operations required to be done after creation of file on upper. + * If @hardlink is false, then @inode is a pre-allocated inode, we may or + * may not use to instantiate the new dentry. + */ +static int ovl_instantiate(struct dentry *dentry, struct inode *inode, + struct dentry *newdentry, bool hardlink) { + struct ovl_inode_params oip = { + .upperdentry = newdentry, + .newinode = inode, + }; + ovl_dentry_version_inc(dentry->d_parent, false); ovl_dentry_set_upper_alias(dentry); if (!hardlink) { - ovl_inode_update(inode, newdentry); - ovl_copyattr(newdentry->d_inode, inode); + /* + * ovl_obtain_alias() can be called after ovl_create_real() + * and before we get here, so we may get an inode from cache + * with the same real upperdentry that is not the inode we + * pre-allocated. In this case we will use the cached inode + * to instantiate the new dentry. + * + * XXX: if we ever use ovl_obtain_alias() to decode directory + * file handles, need to use ovl_get_inode_locked() and + * d_instantiate_new() here to prevent from creating two + * hashed directory inode aliases. + */ + inode = ovl_get_inode(dentry->d_sb, &oip); + if (WARN_ON(IS_ERR(inode))) + return PTR_ERR(inode); } else { WARN_ON(ovl_inode_real(inode) != d_inode(newdentry)); dput(newdentry); inc_nlink(inode); } + d_instantiate(dentry, inode); + if (inode != oip.newinode) { + pr_warn_ratelimited("overlayfs: newly created inode found in cache (%pd2)\n", + dentry); + } + /* Force lookup of new upper hardlink to find its lower */ if (hardlink) d_drop(dentry); + + return 0; } static bool ovl_type_merge(struct dentry *dentry) @@ -285,11 +315,17 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode, ovl_set_opaque(dentry, newdentry); } - ovl_instantiate(dentry, inode, newdentry, !!attr->hardlink); - err = 0; + err = ovl_instantiate(dentry, inode, newdentry, !!attr->hardlink); + if (err) + goto out_cleanup; out_unlock: inode_unlock(udir); return err; + +out_cleanup: + ovl_cleanup(udir, newdentry); + dput(newdentry); + goto out_unlock; } static struct dentry *ovl_clear_empty(struct dentry *dentry, @@ -474,8 +510,9 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, if (err) goto out_cleanup; } - ovl_instantiate(dentry, inode, newdentry, hardlink); - err = 0; + err = ovl_instantiate(dentry, inode, newdentry, hardlink); + if (err) + goto out_cleanup; out_dput: dput(upper); out_unlock: @@ -558,6 +595,7 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, if (err) goto out; + /* Preallocate inode to be used by ovl_get_inode() */ err = -ENOMEM; inode = ovl_new_inode(dentry->d_sb, mode, rdev); if (!inode) @@ -567,7 +605,8 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, attr.mode = inode->i_mode; err = ovl_create_or_link(dentry, inode, &attr, false); - if (err) + /* Did we end up using the preallocated inode? */ + if (inode != d_inode(dentry)) iput(inode); out_drop_write: diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 2b9e8370500c..1db5b3b458a1 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -749,6 +749,15 @@ static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper, return true; } +static struct inode *ovl_iget5(struct super_block *sb, struct inode *newinode, + struct inode *key) +{ + return newinode ? inode_insert5(newinode, (unsigned long) key, + ovl_inode_test, ovl_inode_set, key) : + iget5_locked(sb, (unsigned long) key, + ovl_inode_test, ovl_inode_set, key); +} + struct inode *ovl_get_inode(struct super_block *sb, struct ovl_inode_params *oip) { @@ -776,8 +785,7 @@ struct inode *ovl_get_inode(struct super_block *sb, upperdentry); unsigned int nlink = is_dir ? 1 : realinode->i_nlink; - inode = iget5_locked(sb, (unsigned long) key, ovl_inode_test, - ovl_inode_set, key); + inode = ovl_iget5(sb, oip->newinode, key); if (!inode) goto out_nomem; if (!(inode->i_state & I_NEW)) { diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index b8a0160742b2..3c5e9f18b0d9 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -329,6 +329,7 @@ int ovl_update_time(struct inode *inode, struct timespec *ts, int flags); bool ovl_is_private_xattr(const char *name); struct ovl_inode_params { + struct inode *newinode; struct dentry *upperdentry; struct ovl_path *lowerpath; struct dentry *index; |