diff options
Diffstat (limited to 'fs/overlayfs/inode.c')
| -rw-r--r-- | fs/overlayfs/inode.c | 83 |
1 files changed, 66 insertions, 17 deletions
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index a619addecafc..00b6b294272a 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -15,6 +15,14 @@ #include <linux/ratelimit.h> #include "overlayfs.h" + +static dev_t ovl_get_pseudo_dev(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + return oe->lowerstack[0].layer->pseudo_dev; +} + int ovl_setattr(struct dentry *dentry, struct iattr *attr) { int err; @@ -66,6 +74,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, struct path realpath; const struct cred *old_cred; bool is_dir = S_ISDIR(dentry->d_inode->i_mode); + bool samefs = ovl_same_sb(dentry->d_sb); int err; type = ovl_path_real(dentry, &realpath); @@ -75,16 +84,13 @@ int ovl_getattr(const struct path *path, struct kstat *stat, goto out; /* - * When all layers are on the same fs, all real inode number are - * unique, so we use the overlay st_dev, which is friendly to du -x. - * - * We also use st_ino of the copy up origin, if we know it. - * This guaranties constant st_dev/st_ino across copy up. + * For non-dir or same fs, we use st_ino of the copy up origin, if we + * know it. This guaranties constant st_dev/st_ino across copy up. * * If filesystem supports NFS export ops, this also guaranties * persistent st_ino across mount cycle. */ - if (ovl_same_sb(dentry->d_sb)) { + if (!is_dir || samefs) { if (OVL_TYPE_ORIGIN(type)) { struct kstat lowerstat; u32 lowermask = STATX_INO | (!is_dir ? STATX_NLINK : 0); @@ -95,7 +101,6 @@ int ovl_getattr(const struct path *path, struct kstat *stat, if (err) goto out; - WARN_ON_ONCE(stat->dev != lowerstat.dev); /* * Lower hardlinks may be broken on copy up to different * upper files, so we cannot use the lower origin st_ino @@ -107,17 +112,36 @@ int ovl_getattr(const struct path *path, struct kstat *stat, if (is_dir || lowerstat.nlink == 1 || ovl_test_flag(OVL_INDEX, d_inode(dentry))) stat->ino = lowerstat.ino; + + if (samefs) + WARN_ON_ONCE(stat->dev != lowerstat.dev); + else + stat->dev = ovl_get_pseudo_dev(dentry); } - stat->dev = dentry->d_sb->s_dev; - } else if (is_dir) { + if (samefs) { + /* + * When all layers are on the same fs, all real inode + * number are unique, so we use the overlay st_dev, + * which is friendly to du -x. + */ + stat->dev = dentry->d_sb->s_dev; + } else if (!OVL_TYPE_UPPER(type)) { + /* + * For non-samefs setup, to make sure that st_dev/st_ino + * pair is unique across the system, we use a unique + * anonymous st_dev for lower layer inode. + */ + stat->dev = ovl_get_pseudo_dev(dentry); + } + } else { /* - * If not all layers are on the same fs the pair {real st_ino; - * overlay st_dev} is not unique, so use the non persistent - * overlay st_ino. - * * Always use the overlay st_dev for directories, so 'find * -xdev' will scan the entire overlay mount and won't cross the * overlay mount boundaries. + * + * If not all layers are on the same fs the pair {real st_ino; + * overlay st_dev} is not unique, so use the non persistent + * overlay st_ino for directories. */ stat->dev = dentry->d_sb->s_dev; stat->ino = dentry->d_inode->i_ino; @@ -409,6 +433,7 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode) #ifdef CONFIG_LOCKDEP static struct lock_class_key ovl_i_mutex_key[OVL_MAX_NESTING]; static struct lock_class_key ovl_i_mutex_dir_key[OVL_MAX_NESTING]; + static struct lock_class_key ovl_i_lock_key[OVL_MAX_NESTING]; int depth = inode->i_sb->s_stack_depth - 1; @@ -419,6 +444,8 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode) lockdep_set_class(&inode->i_rwsem, &ovl_i_mutex_dir_key[depth]); else lockdep_set_class(&inode->i_rwsem, &ovl_i_mutex_key[depth]); + + lockdep_set_class(&OVL_I(inode)->lock, &ovl_i_lock_key[depth]); #endif } @@ -598,18 +625,30 @@ static bool ovl_verify_inode(struct inode *inode, struct dentry *lowerdentry, return true; } -struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry) +struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry, + struct dentry *index) { struct dentry *lowerdentry = ovl_dentry_lower(dentry); struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL; struct inode *inode; + /* Already indexed or could be indexed on copy up? */ + bool indexed = (index || (ovl_indexdir(dentry->d_sb) && !upperdentry)); + + if (WARN_ON(upperdentry && indexed && !lowerdentry)) + return ERR_PTR(-EIO); if (!realinode) realinode = d_inode(lowerdentry); - if (!S_ISDIR(realinode->i_mode) && - (upperdentry || (lowerdentry && ovl_indexdir(dentry->d_sb)))) { - struct inode *key = d_inode(lowerdentry ?: upperdentry); + /* + * Copy up origin (lower) may exist for non-indexed upper, but we must + * not use lower as hash key in that case. + * Hash inodes that are or could be indexed by origin inode and + * non-indexed upper inodes that could be hard linked by upper inode. + */ + if (!S_ISDIR(realinode->i_mode) && (upperdentry || indexed)) { + struct inode *key = d_inode(indexed ? lowerdentry : + upperdentry); unsigned int nlink; inode = iget5_locked(dentry->d_sb, (unsigned long) key, @@ -645,6 +684,16 @@ struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry) if (upperdentry && ovl_is_impuredir(upperdentry)) ovl_set_flag(OVL_IMPURE, inode); + /* Check for non-merge dir that may have whiteouts */ + if (S_ISDIR(realinode->i_mode)) { + struct ovl_entry *oe = dentry->d_fsdata; + + if (((upperdentry && lowerdentry) || oe->numlower > 1) || + ovl_check_origin_xattr(upperdentry ?: lowerdentry)) { + ovl_set_flag(OVL_WHITEOUTS, inode); + } + } + if (inode->i_state & I_NEW) unlock_new_inode(inode); out: |