diff options
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/readdir.c | 45 |
1 files changed, 39 insertions, 6 deletions
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index c11f5c0906c3..ef1fe42ff7bb 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -120,6 +120,10 @@ static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd, if (!rdd->dentry) return false; + /* Always recalc d_ino when remapping lower inode numbers */ + if (ovl_xino_bits(rdd->dentry->d_sb)) + return true; + /* Always recalc d_ino for parent */ if (strcmp(p->name, "..") == 0) return true; @@ -435,6 +439,19 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) return cache; } +/* Map inode number to lower fs unique range */ +static u64 ovl_remap_lower_ino(u64 ino, int xinobits, int fsid, + const char *name, int namelen) +{ + if (ino >> (64 - xinobits)) { + pr_warn_ratelimited("overlayfs: d_ino too big (%.*s, ino=%llu, xinobits=%d)\n", + namelen, name, ino, xinobits); + return ino; + } + + return ino | ((u64)fsid) << (64 - xinobits); +} + /* * Set d_ino for upper entries. Non-upper entries should always report * the uppermost real inode ino and should not call this function. @@ -452,9 +469,10 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p) struct dentry *this = NULL; enum ovl_path_type type; u64 ino = p->real_ino; + int xinobits = ovl_xino_bits(dir->d_sb); int err = 0; - if (!ovl_same_sb(dir->d_sb)) + if (!ovl_same_sb(dir->d_sb) && !xinobits) goto out; if (p->name[0] == '.') { @@ -491,6 +509,10 @@ get: WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev); ino = stat.ino; + } else if (xinobits && !OVL_TYPE_UPPER(type)) { + ino = ovl_remap_lower_ino(ino, xinobits, + ovl_layer_lower(this)->fsid, + p->name, p->len); } out: @@ -618,6 +640,8 @@ struct ovl_readdir_translate { struct ovl_dir_cache *cache; struct dir_context ctx; u64 parent_ino; + int fsid; + int xinobits; }; static int ovl_fill_real(struct dir_context *ctx, const char *name, @@ -628,14 +652,17 @@ static int ovl_fill_real(struct dir_context *ctx, const char *name, container_of(ctx, struct ovl_readdir_translate, ctx); struct dir_context *orig_ctx = rdt->orig_ctx; - if (rdt->parent_ino && strcmp(name, "..") == 0) + if (rdt->parent_ino && strcmp(name, "..") == 0) { ino = rdt->parent_ino; - else if (rdt->cache) { + } else if (rdt->cache) { struct ovl_cache_entry *p; p = ovl_cache_entry_find(&rdt->cache->root, name, namelen); if (p) ino = p->ino; + } else if (rdt->xinobits) { + ino = ovl_remap_lower_ino(ino, rdt->xinobits, rdt->fsid, + name, namelen); } return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type); @@ -646,11 +673,16 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx) int err; struct ovl_dir_file *od = file->private_data; struct dentry *dir = file->f_path.dentry; + struct ovl_layer *lower_layer = ovl_layer_lower(dir); struct ovl_readdir_translate rdt = { .ctx.actor = ovl_fill_real, .orig_ctx = ctx, + .xinobits = ovl_xino_bits(dir->d_sb), }; + if (rdt.xinobits && lower_layer) + rdt.fsid = lower_layer->fsid; + if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) { struct kstat stat; struct path statpath = file->f_path; @@ -693,9 +725,10 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) * dir is impure then need to adjust d_ino for copied up * entries. */ - if (ovl_same_sb(dentry->d_sb) && - (ovl_test_flag(OVL_IMPURE, d_inode(dentry)) || - OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent)))) { + if (ovl_xino_bits(dentry->d_sb) || + (ovl_same_sb(dentry->d_sb) && + (ovl_test_flag(OVL_IMPURE, d_inode(dentry)) || + OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) { return ovl_iterate_real(file, ctx); } return iterate_dir(od->realfile, ctx); |