diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 279009dee366..09faa63cf24d 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -62,35 +62,59 @@ struct dentry *ovl_lookup_temp(struct dentry *workdir) } /* caller holds i_mutex on workdir */ -static struct dentry *ovl_whiteout(struct dentry *workdir) +static struct dentry *ovl_whiteout(struct ovl_fs *ofs) { int err; struct dentry *whiteout; + struct dentry *workdir = ofs->workdir; struct inode *wdir = workdir->d_inode; - whiteout = ovl_lookup_temp(workdir); - if (IS_ERR(whiteout)) - return whiteout; + if (!ofs->whiteout) { + whiteout = ovl_lookup_temp(workdir); + if (IS_ERR(whiteout)) + goto out; - err = ovl_do_whiteout(wdir, whiteout); - if (err) { - dput(whiteout); - whiteout = ERR_PTR(err); + err = ovl_do_whiteout(wdir, whiteout); + if (err) { + dput(whiteout); + whiteout = ERR_PTR(err); + goto out; + } + ofs->whiteout = whiteout; } + if (ofs->share_whiteout) { + whiteout = ovl_lookup_temp(workdir); + if (IS_ERR(whiteout)) + goto out; + + err = ovl_do_link(ofs->whiteout, wdir, whiteout); + if (!err) + goto out; + + if (err != -EMLINK) { + pr_warn("Failed to link whiteout - disabling whiteout inode sharing(nlink=%u, err=%i)\n", + ofs->whiteout->d_inode->i_nlink, err); + ofs->share_whiteout = false; + } + dput(whiteout); + } + whiteout = ofs->whiteout; + ofs->whiteout = NULL; +out: return whiteout; } /* Caller must hold i_mutex on both workdir and dir */ -int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir, +int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry) { - struct inode *wdir = workdir->d_inode; + struct inode *wdir = ofs->workdir->d_inode; struct dentry *whiteout; int err; int flags = 0; - whiteout = ovl_whiteout(workdir); + whiteout = ovl_whiteout(ofs); err = PTR_ERR(whiteout); if (IS_ERR(whiteout)) return err; @@ -715,6 +739,7 @@ static bool ovl_matches_upper(struct dentry *dentry, struct dentry *upper) static int ovl_remove_and_whiteout(struct dentry *dentry, struct list_head *list) { + struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct dentry *workdir = ovl_workdir(dentry); struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); struct dentry *upper; @@ -748,7 +773,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, goto out_dput_upper; } - err = ovl_cleanup_and_whiteout(workdir, d_inode(upperdir), upper); + err = ovl_cleanup_and_whiteout(ofs, d_inode(upperdir), upper); if (err) goto out_d_drop; diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index e00b1ff6dea9..76747f5b0517 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -455,7 +455,7 @@ static inline void ovl_copyflags(struct inode *from, struct inode *to) /* dir.c */ extern const struct inode_operations ovl_dir_inode_operations; -int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir, +int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir, struct dentry *dentry); struct ovl_cattr { dev_t rdev; diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 5762d802fe01..a8f82fb7ffb4 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -68,6 +68,7 @@ struct ovl_fs { /* Did we take the inuse lock? */ bool upperdir_locked; bool workdir_locked; + bool share_whiteout; /* Traps in ovl inode cache */ struct inode *upperdir_trap; struct inode *workbasedir_trap; @@ -77,6 +78,8 @@ struct ovl_fs { int xino_mode; /* For allocation of non-persistent inode numbers */ atomic_long_t last_ino; + /* Whiteout dentry cache */ + struct dentry *whiteout; }; static inline struct ovl_fs *OVL_FS(struct super_block *sb) diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 20f5310d3ee4..a10b21b562ad 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -1154,7 +1154,7 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs) * Whiteout orphan index to block future open by * handle after overlay nlink dropped to zero. */ - err = ovl_cleanup_and_whiteout(indexdir, dir, index); + err = ovl_cleanup_and_whiteout(ofs, dir, index); } else { /* Cleanup orphan index entries */ err = ovl_cleanup(dir, index); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index af69f41f564d..a88a7badf444 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -217,6 +217,7 @@ static void ovl_free_fs(struct ovl_fs *ofs) iput(ofs->indexdir_trap); iput(ofs->workdir_trap); iput(ofs->upperdir_trap); + dput(ofs->whiteout); dput(ofs->indexdir); dput(ofs->workdir); if (ofs->workdir_locked) @@ -1776,6 +1777,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) if (!cred) goto out_err; + /* Is there a reason anyone would want not to share whiteouts? */ + ofs->share_whiteout = true; + ofs->config.index = ovl_index_def; ofs->config.nfs_export = ovl_nfs_export_def; ofs->config.xino = ovl_xino_def(); diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index 36b60788ee47..01755bc186c9 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -707,7 +707,8 @@ static void ovl_cleanup_index(struct dentry *dentry) index = NULL; } else if (ovl_index_all(dentry->d_sb)) { /* Whiteout orphan index to block future open by handle */ - err = ovl_cleanup_and_whiteout(indexdir, dir, index); + err = ovl_cleanup_and_whiteout(OVL_FS(dentry->d_sb), + dir, index); } else { /* Cleanup orphan index entries */ err = ovl_cleanup(dir, index);