--- a/fs/jffs2/dir.c +++ b/fs/jffs2/dir.c @@ -34,6 +34,9 @@ static int jffs2_mknod (struct inode *,s static int jffs2_rename (struct inode *, struct dentry *, struct inode *, struct dentry *); +static int jffs2_whiteout (struct inode *, struct dentry *, struct dentry *); +static int jffs2_fallthru (struct inode *, struct dentry *); + const struct file_operations jffs2_dir_operations = { .read = generic_read_dir, @@ -55,6 +58,8 @@ const struct inode_operations jffs2_dir_ .rmdir = jffs2_rmdir, .mknod = jffs2_mknod, .rename = jffs2_rename, + .fallthru = jffs2_fallthru, + .whiteout = jffs2_whiteout, .permission = jffs2_permission, .setattr = jffs2_setattr, .setxattr = jffs2_setxattr, @@ -98,8 +103,21 @@ static struct dentry *jffs2_lookup(struc fd = fd_list; } } - if (fd) - ino = fd->ino; + if (fd) { + spin_lock(&target->d_lock); + switch(fd->type) { + case DT_WHT: + target->d_flags |= DCACHE_WHITEOUT; + break; + case DT_UNKNOWN: + target->d_flags |= DCACHE_FALLTHRU; + break; + default: + ino = fd->ino; + break; + } + spin_unlock(&target->d_lock); + } mutex_unlock(&dir_f->sem); if (ino) { inode = jffs2_iget(dir_i->i_sb, ino); @@ -155,7 +173,9 @@ static int jffs2_readdir(struct file *fi fd->name, fd->ino, fd->type, curofs, offset)); continue; } - if (!fd->ino) { + if (fd->type == DT_UNKNOWN) + fd->ino = 100; /* XXX: arbitrary */ + else if (!fd->ino && (fd->type != DT_WHT)) { D2(printk(KERN_DEBUG "Skipping deletion dirent \"%s\"\n", fd->name)); offset++; continue; @@ -498,6 +518,11 @@ static int jffs2_mkdir (struct inode *di return PTR_ERR(inode); } + if (dentry->d_flags & DCACHE_WHITEOUT) { + inode->i_flags |= S_OPAQUE; + ri->flags = cpu_to_je16(JFFS2_INO_FLAG_OPAQUE); + } + inode->i_op = &jffs2_dir_inode_operations; inode->i_fop = &jffs2_dir_operations; @@ -779,6 +804,82 @@ static int jffs2_mknod (struct inode *di return 0; } +static int jffs2_fallthru (struct inode *dir, struct dentry *dentry) +{ + struct jffs2_sb_info *c = JFFS2_SB_INFO(dir->i_sb); + uint32_t now; + int ret; + + now = get_seconds(); + ret = jffs2_do_link(c, JFFS2_INODE_INFO(dir), 0, DT_UNKNOWN, + dentry->d_name.name, dentry->d_name.len, now); + if (ret) + return ret; + + d_instantiate(dentry, NULL); + spin_lock(&dentry->d_lock); + dentry->d_flags |= DCACHE_FALLTHRU; + spin_unlock(&dentry->d_lock); + + return 0; +} + +static int jffs2_whiteout (struct inode *dir, struct dentry *old_dentry, + struct dentry *new_dentry) +{ + struct jffs2_sb_info *c = JFFS2_SB_INFO(dir->i_sb); + struct jffs2_inode_info *victim_f = NULL; + uint32_t now; + int ret; + + /* If it's a directory, then check whether it is really empty + */ + if (new_dentry->d_inode) { + victim_f = JFFS2_INODE_INFO(old_dentry->d_inode); + if (S_ISDIR(old_dentry->d_inode->i_mode)) { + struct jffs2_full_dirent *fd; + + mutex_lock(&victim_f->sem); + for (fd = victim_f->dents; fd; fd = fd->next) { + if (fd->ino) { + mutex_unlock(&victim_f->sem); + return -ENOTEMPTY; + } + } + mutex_unlock(&victim_f->sem); + } + } + + now = get_seconds(); + ret = jffs2_do_link(c, JFFS2_INODE_INFO(dir), 0, DT_WHT, + new_dentry->d_name.name, new_dentry->d_name.len, now); + if (ret) + return ret; + + spin_lock(&new_dentry->d_lock); + new_dentry->d_flags &= ~DCACHE_FALLTHRU; + new_dentry->d_flags |= DCACHE_WHITEOUT; + spin_unlock(&new_dentry->d_lock); + d_add(new_dentry, NULL); + + if (victim_f) { + /* There was a victim. Kill it off nicely */ + drop_nlink(old_dentry->d_inode); + /* Don't oops if the victim was a dirent pointing to an + inode which didn't exist. */ + if (victim_f->inocache) { + mutex_lock(&victim_f->sem); + if (S_ISDIR(old_dentry->d_inode->i_mode)) + victim_f->inocache->pino_nlink = 0; + else + victim_f->inocache->pino_nlink--; + mutex_unlock(&victim_f->sem); + } + } + + return 0; +} + static int jffs2_rename (struct inode *old_dir_i, struct dentry *old_dentry, struct inode *new_dir_i, struct dentry *new_dentry) { --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -301,6 +301,10 @@ struct inode *jffs2_iget(struct super_bl inode->i_op = &jffs2_dir_inode_operations; inode->i_fop = &jffs2_dir_operations; + + if (je16_to_cpu(latest_node.flags) & JFFS2_INO_FLAG_OPAQUE) + inode->i_flags |= S_OPAQUE; + break; } case S_IFREG: --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -172,7 +172,7 @@ static int jffs2_fill_super(struct super sb->s_op = &jffs2_super_operations; sb->s_export_op = &jffs2_export_ops; - sb->s_flags = sb->s_flags | MS_NOATIME; + sb->s_flags = sb->s_flags | MS_NOATIME | MS_WHITEOUT; sb->s_xattr = jffs2_xattr_handlers; #ifdef CONFIG_JFFS2_FS_POSIX_ACL sb->s_flags |= MS_POSIXACL; --- a/include/linux/jffs2.h +++ b/include/linux/jffs2.h @@ -87,6 +87,8 @@ #define JFFS2_INO_FLAG_USERCOMPR 2 /* User has requested a specific compression type */ +#define JFFS2_INO_FLAG_OPAQUE 4 /* Directory is opaque (for union mounts) */ + /* These can go once we've made sure we've caught all uses without byteswapping */