From 6b2d5fe46fa8f4fc1c5262c73930b9a2a94db2e3 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Fri, 16 Dec 2016 11:02:56 +0100 Subject: ovl: check namelen We already calculate f_namelen in statfs as the maximum of the name lengths provided by the filesystems taking part in the overlay. Signed-off-by: Miklos Szeredi --- fs/overlayfs/super.c | 38 ++++++++++++++++++++++++++------------ 1 file changed, 26 insertions(+), 12 deletions(-) (limited to 'fs/overlayfs/super.c') diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 011482e74096..e19e2ed6a4fd 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -174,7 +174,7 @@ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) err = vfs_statfs(&path, buf); if (!err) { - buf->f_namelen = max(buf->f_namelen, ofs->lower_namelen); + buf->f_namelen = ofs->namelen; buf->f_type = OVERLAYFS_SUPER_MAGIC; } @@ -461,22 +461,33 @@ static int ovl_mount_dir(const char *name, struct path *path) return err; } -static int ovl_lower_dir(const char *name, struct path *path, long *namelen, - int *stack_depth, bool *remote) +static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs, + const char *name) { - int err; struct kstatfs statfs; + int err = vfs_statfs(path, &statfs); + + if (err) + pr_err("overlayfs: statfs failed on '%s'\n", name); + else + ofs->namelen = max(ofs->namelen, statfs.f_namelen); + + return err; +} + +static int ovl_lower_dir(const char *name, struct path *path, + struct ovl_fs *ofs, int *stack_depth, bool *remote) +{ + int err; err = ovl_mount_dir_noesc(name, path); if (err) goto out; - err = vfs_statfs(path, &statfs); - if (err) { - pr_err("overlayfs: statfs failed on '%s'\n", name); + err = ovl_check_namelen(path, ofs, name); + if (err) goto out_put; - } - *namelen = max(*namelen, statfs.f_namelen); + *stack_depth = max(*stack_depth, path->mnt->mnt_sb->s_stack_depth); if (ovl_dentry_remote(path->dentry)) @@ -708,6 +719,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) goto out_put_upperpath; } + err = ovl_check_namelen(&upperpath, ufs, ufs->config.upperdir); + if (err) + goto out_put_upperpath; + err = ovl_mount_dir(ufs->config.workdir, &workpath); if (err) goto out_put_upperpath; @@ -745,9 +760,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) lower = lowertmp; for (numlower = 0; numlower < stacklen; numlower++) { - err = ovl_lower_dir(lower, &stack[numlower], - &ufs->lower_namelen, &sb->s_stack_depth, - &remote); + err = ovl_lower_dir(lower, &stack[numlower], ufs, + &sb->s_stack_depth, &remote); if (err) goto out_put_lowerpath; -- cgit v1.2.1