From 12574a9f4c9cc9d8d6fd9078cbb8ec7d3e9ed46b Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Fri, 16 Mar 2018 10:39:37 +0200 Subject: [PATCH] ovl: consistent i_ino for non-samefs with xino When overlay layers are not all on the same fs, but all inode numbers of underlying fs do not use the high 'xino' bits, overlay st_ino values are constant and persistent. In that case, set i_ino value to the same value as st_ino for nfsd readdirplus validator. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- fs/overlayfs/export.c | 2 +- fs/overlayfs/inode.c | 27 ++++++++++++++++++--------- fs/overlayfs/namei.c | 4 +--- fs/overlayfs/overlayfs.h | 2 +- 4 files changed, 21 insertions(+), 14 deletions(-) diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c index bb290cd1e727..425a94672300 100644 --- a/fs/overlayfs/export.c +++ b/fs/overlayfs/export.c @@ -305,7 +305,7 @@ static struct dentry *ovl_obtain_alias(struct super_block *sb, if (d_is_dir(upper ?: lower)) return ERR_PTR(-EIO); - inode = ovl_get_inode(sb, dget(upper), lower, index, !!lower); + inode = ovl_get_inode(sb, dget(upper), lowerpath, index, !!lower); if (IS_ERR(inode)) { dput(upper); return ERR_CAST(inode); diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 51d780898d89..6e3815fb006b 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -489,19 +489,26 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode) } static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev, - unsigned long ino) + unsigned long ino, int fsid) { + int xinobits = ovl_xino_bits(inode->i_sb); + /* * When NFS export is enabled and d_ino is consistent with st_ino - * (samefs), set the same value to i_ino, because nfsd readdirplus - * compares d_ino values to i_ino values of child entries. When called - * from ovl_new_inode(), ino arg is 0, so i_ino will be updated to real + * (samefs or i_ino has enough bits to encode layer), set the same + * value used for d_ino to i_ino, because nfsd readdirplus compares + * d_ino values to i_ino values of child entries. When called from + * ovl_new_inode(), ino arg is 0, so i_ino will be updated to real * upper inode i_ino on ovl_inode_init() or ovl_inode_update(). */ - if (inode->i_sb->s_export_op && ovl_same_sb(inode->i_sb)) + if (inode->i_sb->s_export_op && + (ovl_same_sb(inode->i_sb) || xinobits)) { inode->i_ino = ino; - else + if (xinobits && fsid && !(ino >> (64 - xinobits))) + inode->i_ino |= (unsigned long)fsid << (64 - xinobits); + } else { inode->i_ino = get_next_ino(); + } inode->i_mode = mode; inode->i_flags |= S_NOCMTIME; #ifdef CONFIG_FS_POSIX_ACL @@ -637,7 +644,7 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev) inode = new_inode(sb); if (inode) - ovl_fill_inode(inode, mode, rdev, 0); + ovl_fill_inode(inode, mode, rdev, 0, 0); return inode; } @@ -743,12 +750,14 @@ static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper, } struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry, - struct dentry *lowerdentry, struct dentry *index, + struct ovl_path *lowerpath, struct dentry *index, unsigned int numlower) { struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL; struct inode *inode; + struct dentry *lowerdentry = lowerpath ? lowerpath->dentry : NULL; bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry, index); + int fsid = bylower ? lowerpath->layer->fsid : 0; bool is_dir; unsigned long ino = 0; @@ -796,7 +805,7 @@ struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry, if (!inode) goto out_nomem; } - ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino); + ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid); ovl_inode_init(inode, upperdentry, lowerdentry); if (upperdentry && ovl_is_impuredir(upperdentry)) diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 52f0b13be633..2dba29eadde6 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -1004,9 +1004,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, upperdentry = dget(index); if (upperdentry || ctr) { - if (ctr) - origin = stack[0].dentry; - inode = ovl_get_inode(dentry->d_sb, upperdentry, origin, index, + inode = ovl_get_inode(dentry->d_sb, upperdentry, stack, index, ctr); err = PTR_ERR(inode); if (IS_ERR(inode)) diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 8eefc309aeb6..e0b7de799f6b 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -338,7 +338,7 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev); struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real, bool is_upper); struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry, - struct dentry *lowerdentry, struct dentry *index, + struct ovl_path *lowerpath, struct dentry *index, unsigned int numlower); static inline void ovl_copyattr(struct inode *from, struct inode *to) {