From 9cf8ddb12a728a5b9d814dc2c12dfc0959539f9c Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Wed, 28 Jan 2026 14:24:06 +0100 Subject: [PATCH] ovl: use name_is_dot* helpers in readdir code Use the helpers in place of all the different open coded variants. This makes the code more readable and robust. Signed-off-by: Amir Goldstein Link: https://patch.msgid.link/20260128132406.23768-4-amir73il@gmail.com Reviewed-by: Eric Biggers Signed-off-by: Christian Brauner --- fs/overlayfs/readdir.c | 38 +++++++++++++------------------------- 1 file changed, 13 insertions(+), 25 deletions(-) diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 9f6b36f3d4cf..c665ff3546f7 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -154,7 +154,7 @@ static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd, return true; /* Always recalc d_ino for parent */ - if (strcmp(p->name, "..") == 0) + if (name_is_dotdot(p->name, p->len)) return true; /* If this is lower, then native d_ino will do */ @@ -165,7 +165,7 @@ static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd, * Recalc d_ino for '.' and for all entries if dir is impure (contains * copied up entries) */ - if ((p->name[0] == '.' && p->len == 1) || + if (name_is_dot(p->name, p->len) || ovl_test_flag(OVL_IMPURE, d_inode(rdd->dentry))) return true; @@ -561,12 +561,12 @@ static int ovl_cache_update(const struct path *path, struct ovl_cache_entry *p, if (!ovl_same_dev(ofs) && !p->check_xwhiteout) goto out; - if (p->name[0] == '.') { + if (name_is_dot_dotdot(p->name, p->len)) { if (p->len == 1) { this = dget(dir); goto get; } - if (p->len == 2 && p->name[1] == '.') { + if (p->len == 2) { /* we shall not be moved */ this = dget(dir->d_parent); goto get; @@ -666,8 +666,7 @@ static int ovl_dir_read_impure(const struct path *path, struct list_head *list, return err; list_for_each_entry_safe(p, n, list, l_node) { - if (strcmp(p->name, ".") != 0 && - strcmp(p->name, "..") != 0) { + if (!name_is_dot_dotdot(p->name, p->len)) { err = ovl_cache_update(path, p, true); if (err) return err; @@ -756,7 +755,7 @@ static bool ovl_fill_real(struct dir_context *ctx, const char *name, struct dir_context *orig_ctx = rdt->orig_ctx; bool res; - if (rdt->parent_ino && namelen == 2 && !strncmp(name, "..", 2)) { + if (rdt->parent_ino && name_is_dotdot(name, namelen)) { ino = rdt->parent_ino; } else if (rdt->cache) { struct ovl_cache_entry *p; @@ -1097,12 +1096,8 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) goto del_entry; } - if (p->name[0] == '.') { - if (p->len == 1) - goto del_entry; - if (p->len == 2 && p->name[1] == '.') - goto del_entry; - } + if (name_is_dot_dotdot(p->name, p->len)) + goto del_entry; err = -ENOTEMPTY; break; @@ -1146,7 +1141,7 @@ static bool ovl_check_d_type(struct dir_context *ctx, const char *name, container_of(ctx, struct ovl_readdir_data, ctx); /* Even if d_type is not supported, DT_DIR is returned for . and .. */ - if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen)) + if (name_is_dot_dotdot(name, namelen)) return true; if (d_type != DT_UNKNOWN) @@ -1209,11 +1204,8 @@ static int ovl_workdir_cleanup_recurse(struct ovl_fs *ofs, const struct path *pa list_for_each_entry(p, &list, l_node) { struct dentry *dentry; - if (p->name[0] == '.') { - if (p->len == 1) - continue; - if (p->len == 2 && p->name[1] == '.') - continue; + if (name_is_dot_dotdot(p->name, p->len)) { + continue; } else if (incompat) { pr_err("overlay with incompat feature '%s' cannot be mounted\n", p->name); @@ -1278,12 +1270,8 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs) goto out; list_for_each_entry(p, &list, l_node) { - if (p->name[0] == '.') { - if (p->len == 1) - continue; - if (p->len == 2 && p->name[1] == '.') - continue; - } + if (name_is_dot_dotdot(p->name, p->len)) + continue; index = ovl_lookup_upper_unlocked(ofs, p->name, indexdir, p->len); if (IS_ERR(index)) { err = PTR_ERR(index); -- 2.47.3