From 4155c10a0309523924b934b81d08aac03f15c990 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Fri, 10 Nov 2017 09:39:15 +0100 Subject: [PATCH] ovl: clean up getting lower layers Move calling ovl_get_lower_layers() into ovl_get_lowerstack(). ovl_get_lowerstack() now returns the root dentry's filled in ovl_entry. Signed-off-by: Miklos Szeredi --- fs/overlayfs/super.c | 100 +++++++++++++++++++++---------------------- 1 file changed, 48 insertions(+), 52 deletions(-) diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 115cbf3303de..e4852cb1ec64 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -38,15 +38,20 @@ module_param_named(index, ovl_index_def, bool, 0644); MODULE_PARM_DESC(ovl_index_def, "Default to on or off for the inodes index feature"); +static void ovl_entry_stack_free(struct ovl_entry *oe) +{ + unsigned int i; + + for (i = 0; i < oe->numlower; i++) + dput(oe->lowerstack[i].dentry); +} + static void ovl_dentry_release(struct dentry *dentry) { struct ovl_entry *oe = dentry->d_fsdata; if (oe) { - unsigned int i; - - for (i = 0; i < oe->numlower; i++) - dput(oe->lowerstack[i].dentry); + ovl_entry_stack_free(oe); kfree_rcu(oe, rcu); } } @@ -1058,35 +1063,36 @@ out: return err; } -static int ovl_get_lowerstack(struct super_block *sb, struct ovl_fs *ufs, - struct path **stackp, unsigned int *stacklenp) +static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, + struct ovl_fs *ufs) { int err; char *lowertmp, *lower; - struct path *stack; - unsigned int stacklen, numlower, i; + struct path *stack = NULL; + unsigned int stacklen, numlower = 0, i; bool remote = false; + struct ovl_entry *oe; err = -ENOMEM; lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL); if (!lowertmp) - goto out; + goto out_err; err = -EINVAL; stacklen = ovl_split_lowerdirs(lowertmp); if (stacklen > OVL_MAX_STACK) { pr_err("overlayfs: too many lower directories, limit is %d\n", OVL_MAX_STACK); - goto out; + goto out_err; } else if (!ufs->config.upperdir && stacklen == 1) { pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n"); - goto out; + goto out_err; } err = -ENOMEM; stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL); if (!stack) - goto out; + goto out_err; err = -EINVAL; lower = lowertmp; @@ -1094,7 +1100,7 @@ static int ovl_get_lowerstack(struct super_block *sb, struct ovl_fs *ufs, err = ovl_lower_dir(lower, &stack[numlower], ufs, &sb->s_stack_depth, &remote); if (err) - goto out_free_stack; + goto out_err; lower = strchr(lower, '\0') + 1; } @@ -1103,27 +1109,38 @@ static int ovl_get_lowerstack(struct super_block *sb, struct ovl_fs *ufs, sb->s_stack_depth++; if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { pr_err("overlayfs: maximum fs stacking depth exceeded\n"); - goto out_free_stack; + goto out_err; } - *stackp = stack; - *stacklenp = numlower; + err = ovl_get_lower_layers(ufs, stack, numlower); + if (err) + goto out_err; + + err = -ENOMEM; + oe = ovl_alloc_entry(numlower); + if (!oe) + goto out_err; + + for (i = 0; i < numlower; i++) { + oe->lowerstack[i].dentry = dget(stack[i].dentry); + oe->lowerstack[i].layer = &ufs->lower_layers[i]; + } if (remote) sb->s_d_op = &ovl_reval_dentry_operations; else sb->s_d_op = &ovl_dentry_operations; - err = 0; - out: - kfree(lowertmp); - return err; - -out_free_stack: for (i = 0; i < numlower; i++) path_put(&stack[i]); kfree(stack); + kfree(lowertmp); + + return oe; + +out_err: + oe = ERR_PTR(err); goto out; } @@ -1131,11 +1148,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) { struct path upperpath = { }; struct dentry *root_dentry; - struct ovl_entry *oe = NULL; + struct ovl_entry *oe; struct ovl_fs *ufs; - struct path *stack = NULL; - unsigned int numlower = 0; - unsigned int i; struct cred *cred; int err; @@ -1184,12 +1198,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) sb->s_time_gran = ufs->upper_mnt->mnt_sb->s_time_gran; } - err = ovl_get_lowerstack(sb, ufs, &stack, &numlower); - if (err) - goto out_err; - - err = ovl_get_lower_layers(ufs, stack, numlower); - if (err) + oe = ovl_get_lowerstack(sb, ufs); + err = PTR_ERR(oe); + if (IS_ERR(oe)) goto out_err; /* If the upper fs is nonexistent, we mark overlayfs r/o too */ @@ -1198,20 +1209,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) else if (ufs->upper_mnt->mnt_sb != ufs->same_sb) ufs->same_sb = NULL; - err = -ENOMEM; - oe = ovl_alloc_entry(numlower); - if (!oe) - goto out_err; - - for (i = 0; i < numlower; i++) { - oe->lowerstack[i].dentry = stack[i].dentry; - oe->lowerstack[i].layer = &(ufs->lower_layers[i]); - } - if (!(ovl_force_readonly(ufs)) && ufs->config.index) { err = ovl_get_indexdir(ufs, oe, &upperpath); if (err) - goto out_err; + goto out_free_oe; if (!ufs->indexdir) sb->s_flags |= MS_RDONLY; @@ -1233,13 +1234,9 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) err = -ENOMEM; root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0)); if (!root_dentry) - goto out_err; + goto out_free_oe; mntput(upperpath.mnt); - for (i = 0; i < numlower; i++) - mntput(stack[i].mnt); - kfree(stack); - if (upperpath.dentry) { oe->has_upper = true; if (ovl_is_impuredir(upperpath.dentry)) @@ -1257,11 +1254,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) return 0; -out_err: +out_free_oe: + ovl_entry_stack_free(oe); kfree(oe); - for (i = 0; i < numlower; i++) - path_put(&stack[i]); - kfree(stack); +out_err: path_put(&upperpath); ovl_free_fs(ufs); out: