diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index c441f9387a1b..eb3b8d39fb61 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -22,7 +22,6 @@ #include #include #include "overlayfs.h" -#include "ovl_entry.h" #define OVL_COPY_UP_CHUNK_SIZE (1 << 20) @@ -486,6 +485,7 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) static int ovl_copy_up_locked(struct ovl_copy_up_ctx *c) { struct inode *udir = c->destdir->d_inode; + struct inode *inode; struct dentry *newdentry = NULL; struct dentry *temp = NULL; int err; @@ -508,7 +508,11 @@ static int ovl_copy_up_locked(struct ovl_copy_up_ctx *c) if (err) goto out_cleanup; - ovl_inode_update(d_inode(c->dentry), newdentry); + inode = d_inode(c->dentry); + ovl_inode_update(inode, newdentry); + if (S_ISDIR(inode->i_mode)) + ovl_set_flag(OVL_WHITEOUTS, inode); + out: dput(temp); return err; diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index cc961a3bd3bd..e13921824c70 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -181,6 +181,11 @@ static bool ovl_type_origin(struct dentry *dentry) return OVL_TYPE_ORIGIN(ovl_path_type(dentry)); } +static bool ovl_may_have_whiteouts(struct dentry *dentry) +{ + return ovl_test_flag(OVL_WHITEOUTS, d_inode(dentry)); +} + static int ovl_create_upper(struct dentry *dentry, struct inode *inode, struct cattr *attr, struct dentry *hardlink) { @@ -300,7 +305,6 @@ static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry) { int err; struct dentry *ret = NULL; - enum ovl_path_type type = ovl_path_type(dentry); LIST_HEAD(list); err = ovl_check_empty_dir(dentry, &list); @@ -313,13 +317,13 @@ static struct dentry *ovl_check_empty_and_clear(struct dentry *dentry) * When removing an empty opaque directory, then it makes no sense to * replace it with an exact replica of itself. * - * If no upperdentry then skip clearing whiteouts. + * If upperdentry has whiteouts, clear them. * * Can race with copy-up, since we don't hold the upperdir mutex. * Doesn't matter, since copy-up can't create a non-empty directory * from an empty one. */ - if (OVL_TYPE_UPPER(type) && OVL_TYPE_MERGE(type)) + if (!list_empty(&list)) ret = ovl_clear_empty(dentry, &list); out_free: @@ -698,8 +702,9 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) struct dentry *opaquedir = NULL; int err; - /* Redirect dir can be !ovl_lower_positive && OVL_TYPE_MERGE */ - if (is_dir && ovl_dentry_get_redirect(dentry)) { + /* Redirect/origin dir can be !ovl_lower_positive && not clean */ + if (is_dir && (ovl_dentry_get_redirect(dentry) || + ovl_may_have_whiteouts(dentry))) { opaquedir = ovl_check_empty_and_clear(dentry); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) @@ -946,7 +951,8 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, old_cred = ovl_override_creds(old->d_sb); - if (overwrite && new_is_dir && ovl_type_merge_or_lower(new)) { + if (overwrite && new_is_dir && (ovl_type_merge_or_lower(new) || + ovl_may_have_whiteouts(new))) { opaquedir = ovl_check_empty_and_clear(new); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) { @@ -1069,9 +1075,10 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, drop_nlink(d_inode(new)); } - ovl_dentry_version_inc(old->d_parent, - !overwrite && ovl_type_origin(new)); - ovl_dentry_version_inc(new->d_parent, ovl_type_origin(old)); + ovl_dentry_version_inc(old->d_parent, ovl_type_origin(old) || + (!overwrite && ovl_type_origin(new))); + ovl_dentry_version_inc(new->d_parent, ovl_type_origin(old) || + (d_inode(new) && ovl_type_origin(new))); out_dput: dput(newdentry); diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 321511ed8c42..00b6b294272a 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -15,6 +15,14 @@ #include #include "overlayfs.h" + +static dev_t ovl_get_pseudo_dev(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + return oe->lowerstack[0].layer->pseudo_dev; +} + int ovl_setattr(struct dentry *dentry, struct iattr *attr) { int err; @@ -66,6 +74,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat, struct path realpath; const struct cred *old_cred; bool is_dir = S_ISDIR(dentry->d_inode->i_mode); + bool samefs = ovl_same_sb(dentry->d_sb); int err; type = ovl_path_real(dentry, &realpath); @@ -75,16 +84,13 @@ int ovl_getattr(const struct path *path, struct kstat *stat, goto out; /* - * When all layers are on the same fs, all real inode number are - * unique, so we use the overlay st_dev, which is friendly to du -x. - * - * We also use st_ino of the copy up origin, if we know it. - * This guaranties constant st_dev/st_ino across copy up. + * For non-dir or same fs, we use st_ino of the copy up origin, if we + * know it. This guaranties constant st_dev/st_ino across copy up. * * If filesystem supports NFS export ops, this also guaranties * persistent st_ino across mount cycle. */ - if (ovl_same_sb(dentry->d_sb)) { + if (!is_dir || samefs) { if (OVL_TYPE_ORIGIN(type)) { struct kstat lowerstat; u32 lowermask = STATX_INO | (!is_dir ? STATX_NLINK : 0); @@ -95,7 +101,6 @@ int ovl_getattr(const struct path *path, struct kstat *stat, if (err) goto out; - WARN_ON_ONCE(stat->dev != lowerstat.dev); /* * Lower hardlinks may be broken on copy up to different * upper files, so we cannot use the lower origin st_ino @@ -107,17 +112,36 @@ int ovl_getattr(const struct path *path, struct kstat *stat, if (is_dir || lowerstat.nlink == 1 || ovl_test_flag(OVL_INDEX, d_inode(dentry))) stat->ino = lowerstat.ino; + + if (samefs) + WARN_ON_ONCE(stat->dev != lowerstat.dev); + else + stat->dev = ovl_get_pseudo_dev(dentry); } - stat->dev = dentry->d_sb->s_dev; - } else if (is_dir) { + if (samefs) { + /* + * When all layers are on the same fs, all real inode + * number are unique, so we use the overlay st_dev, + * which is friendly to du -x. + */ + stat->dev = dentry->d_sb->s_dev; + } else if (!OVL_TYPE_UPPER(type)) { + /* + * For non-samefs setup, to make sure that st_dev/st_ino + * pair is unique across the system, we use a unique + * anonymous st_dev for lower layer inode. + */ + stat->dev = ovl_get_pseudo_dev(dentry); + } + } else { /* - * If not all layers are on the same fs the pair {real st_ino; - * overlay st_dev} is not unique, so use the non persistent - * overlay st_ino. - * * Always use the overlay st_dev for directories, so 'find * -xdev' will scan the entire overlay mount and won't cross the * overlay mount boundaries. + * + * If not all layers are on the same fs the pair {real st_ino; + * overlay st_dev} is not unique, so use the non persistent + * overlay st_ino for directories. */ stat->dev = dentry->d_sb->s_dev; stat->ino = dentry->d_inode->i_ino; @@ -409,6 +433,7 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode) #ifdef CONFIG_LOCKDEP static struct lock_class_key ovl_i_mutex_key[OVL_MAX_NESTING]; static struct lock_class_key ovl_i_mutex_dir_key[OVL_MAX_NESTING]; + static struct lock_class_key ovl_i_lock_key[OVL_MAX_NESTING]; int depth = inode->i_sb->s_stack_depth - 1; @@ -419,6 +444,8 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode) lockdep_set_class(&inode->i_rwsem, &ovl_i_mutex_dir_key[depth]); else lockdep_set_class(&inode->i_rwsem, &ovl_i_mutex_key[depth]); + + lockdep_set_class(&OVL_I(inode)->lock, &ovl_i_lock_key[depth]); #endif } @@ -657,6 +684,16 @@ struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry, if (upperdentry && ovl_is_impuredir(upperdentry)) ovl_set_flag(OVL_IMPURE, inode); + /* Check for non-merge dir that may have whiteouts */ + if (S_ISDIR(realinode->i_mode)) { + struct ovl_entry *oe = dentry->d_fsdata; + + if (((upperdentry && lowerdentry) || oe->numlower > 1) || + ovl_check_origin_xattr(upperdentry ?: lowerdentry)) { + ovl_set_flag(OVL_WHITEOUTS, inode); + } + } + if (inode->i_state & I_NEW) unlock_new_inode(inode); out: diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index a12dc10bf726..625ed8066570 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -15,7 +15,6 @@ #include #include #include "overlayfs.h" -#include "ovl_entry.h" struct ovl_lookup_data { struct qstr name; @@ -286,16 +285,15 @@ static int ovl_lookup_layer(struct dentry *base, struct ovl_lookup_data *d, static int ovl_check_origin(struct dentry *upperdentry, - struct path *lowerstack, unsigned int numlower, - struct path **stackp, unsigned int *ctrp) + struct ovl_path *lower, unsigned int numlower, + struct ovl_path **stackp, unsigned int *ctrp) { struct vfsmount *mnt; struct dentry *origin = NULL; int i; - for (i = 0; i < numlower; i++) { - mnt = lowerstack[i].mnt; + mnt = lower[i].layer->mnt; origin = ovl_get_origin(upperdentry, mnt); if (IS_ERR(origin)) return PTR_ERR(origin); @@ -309,12 +307,12 @@ static int ovl_check_origin(struct dentry *upperdentry, BUG_ON(*ctrp); if (!*stackp) - *stackp = kmalloc(sizeof(struct path), GFP_KERNEL); + *stackp = kmalloc(sizeof(struct ovl_path), GFP_KERNEL); if (!*stackp) { dput(origin); return -ENOMEM; } - **stackp = (struct path) { .dentry = origin, .mnt = mnt }; + **stackp = (struct ovl_path){.dentry = origin, .layer = lower[i].layer}; *ctrp = 1; return 0; @@ -350,8 +348,8 @@ static int ovl_verify_origin_fh(struct dentry *dentry, const struct ovl_fh *fh) * * Return 0 on match, -ESTALE on mismatch, < 0 on error. */ -int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt, - struct dentry *origin, bool is_upper, bool set) +int ovl_verify_origin(struct dentry *dentry, struct dentry *origin, + bool is_upper, bool set) { struct inode *inode; struct ovl_fh *fh; @@ -384,13 +382,13 @@ fail: * OVL_XATTR_ORIGIN and that origin file handle can be decoded to lower path. * Return 0 on match, -ESTALE on mismatch or stale origin, < 0 on error. */ -int ovl_verify_index(struct dentry *index, struct path *lowerstack, +int ovl_verify_index(struct dentry *index, struct ovl_path *lower, unsigned int numlower) { struct ovl_fh *fh = NULL; size_t len; - struct path origin = { }; - struct path *stack = &origin; + struct ovl_path origin = { }; + struct ovl_path *stack = &origin; unsigned int ctr = 0; int err; @@ -429,7 +427,7 @@ int ovl_verify_index(struct dentry *index, struct path *lowerstack, if (err) goto fail; - err = ovl_check_origin(index, lowerstack, numlower, &stack, &ctr); + err = ovl_check_origin(index, lower, numlower, &stack, &ctr); if (!err && !ctr) err = -ESTALE; if (err) @@ -568,11 +566,24 @@ int ovl_path_next(int idx, struct dentry *dentry, struct path *path) idx++; } BUG_ON(idx > oe->numlower); - *path = oe->lowerstack[idx - 1]; + path->dentry = oe->lowerstack[idx - 1].dentry; + path->mnt = oe->lowerstack[idx - 1].layer->mnt; return (idx < oe->numlower) ? idx + 1 : -1; } +static int ovl_find_layer(struct ovl_fs *ofs, struct ovl_path *path) +{ + int i; + + for (i = 0; i < ofs->numlower; i++) { + if (ofs->lower_layers[i].mnt == path->layer->mnt) + break; + } + + return i; +} + struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags) { @@ -581,7 +592,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, struct ovl_fs *ofs = dentry->d_sb->s_fs_info; struct ovl_entry *poe = dentry->d_parent->d_fsdata; struct ovl_entry *roe = dentry->d_sb->s_root->d_fsdata; - struct path *stack = NULL; + struct ovl_path *stack = NULL; struct dentry *upperdir, *upperdentry = NULL; struct dentry *index = NULL; unsigned int ctr = 0; @@ -630,7 +641,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, err = ovl_check_origin(upperdentry, roe->lowerstack, roe->numlower, &stack, &ctr); if (err) - goto out; + goto out_put_upper; } if (d.redirect) { @@ -646,17 +657,17 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, if (!d.stop && poe->numlower) { err = -ENOMEM; - stack = kcalloc(ofs->numlower, sizeof(struct path), + stack = kcalloc(ofs->numlower, sizeof(struct ovl_path), GFP_KERNEL); if (!stack) goto out_put_upper; } for (i = 0; !d.stop && i < poe->numlower; i++) { - struct path lowerpath = poe->lowerstack[i]; + struct ovl_path lower = poe->lowerstack[i]; d.last = i == poe->numlower - 1; - err = ovl_lookup_layer(lowerpath.dentry, &d, &this); + err = ovl_lookup_layer(lower.dentry, &d, &this); if (err) goto out_put; @@ -664,7 +675,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, continue; stack[ctr].dentry = this; - stack[ctr].mnt = lowerpath.mnt; + stack[ctr].layer = lower.layer; ctr++; if (d.stop) @@ -674,10 +685,8 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, poe = roe; /* Find the current layer on the root dentry */ - for (i = 0; i < poe->numlower; i++) - if (poe->lowerstack[i].mnt == lowerpath.mnt) - break; - if (WARN_ON(i == poe->numlower)) + i = ovl_find_layer(ofs, &lower); + if (WARN_ON(i == ofs->numlower)) break; } } @@ -700,7 +709,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, goto out_put; oe->opaque = upperopaque; - memcpy(oe->lowerstack, stack, sizeof(struct path) * ctr); + memcpy(oe->lowerstack, stack, sizeof(struct ovl_path) * ctr); dentry->d_fsdata = oe; if (upperdentry) diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index d9a0edd4e57e..13eab09a6b6f 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -9,6 +9,7 @@ #include #include +#include "ovl_entry.h" enum ovl_path_type { __OVL_PATH_UPPER = (1 << 0), @@ -28,7 +29,10 @@ enum ovl_path_type { #define OVL_XATTR_NLINK OVL_XATTR_PREFIX "nlink" enum ovl_flag { + /* Pure upper dir that may contain non pure upper entries */ OVL_IMPURE, + /* Non-merge dir that may contain whiteout entries */ + OVL_WHITEOUTS, OVL_INDEX, }; @@ -223,6 +227,7 @@ bool ovl_is_whiteout(struct dentry *dentry); struct file *ovl_path_open(struct path *path, int flags); int ovl_copy_up_start(struct dentry *dentry); void ovl_copy_up_end(struct dentry *dentry); +bool ovl_check_origin_xattr(struct dentry *dentry); bool ovl_check_dir_xattr(struct dentry *dentry, const char *name); int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, const char *name, const void *value, size_t size, @@ -244,9 +249,9 @@ static inline bool ovl_is_impuredir(struct dentry *dentry) /* namei.c */ -int ovl_verify_origin(struct dentry *dentry, struct vfsmount *mnt, - struct dentry *origin, bool is_upper, bool set); -int ovl_verify_index(struct dentry *index, struct path *lowerstack, +int ovl_verify_origin(struct dentry *dentry, struct dentry *origin, + bool is_upper, bool set); +int ovl_verify_index(struct dentry *index, struct ovl_path *lower, unsigned int numlower); int ovl_get_index_name(struct dentry *origin, struct qstr *name); int ovl_path_next(int idx, struct dentry *dentry, struct path *path); @@ -263,7 +268,7 @@ int ovl_check_d_type_supported(struct path *realpath); void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, struct dentry *dentry, int level); int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, - struct path *lowerstack, unsigned int numlower); + struct ovl_path *lower, unsigned int numlower); /* inode.c */ int ovl_set_nlink_upper(struct dentry *dentry); diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h index 36b49bd09264..752bab645879 100644 --- a/fs/overlayfs/ovl_entry.h +++ b/fs/overlayfs/ovl_entry.h @@ -17,11 +17,21 @@ struct ovl_config { bool index; }; +struct ovl_layer { + struct vfsmount *mnt; + dev_t pseudo_dev; +}; + +struct ovl_path { + struct ovl_layer *layer; + struct dentry *dentry; +}; + /* private information held for overlayfs's superblock */ struct ovl_fs { struct vfsmount *upper_mnt; unsigned numlower; - struct vfsmount **lower_mnt; + struct ovl_layer *lower_layers; /* workbasedir is the path at workdir= mount option */ struct dentry *workbasedir; /* workdir is the 'work' directory under workbasedir */ @@ -52,7 +62,7 @@ struct ovl_entry { struct rcu_head rcu; }; unsigned numlower; - struct path lowerstack[]; + struct ovl_path lowerstack[]; }; struct ovl_entry *ovl_alloc_entry(unsigned int numlower); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index c310e3ff7f3f..0daa4354fec4 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -26,6 +26,7 @@ struct ovl_cache_entry { struct list_head l_node; struct rb_node node; struct ovl_cache_entry *next_maybe_whiteout; + bool is_upper; bool is_whiteout; char name[]; }; @@ -158,6 +159,7 @@ static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, /* Defer setting d_ino for upper entry to ovl_iterate() */ if (ovl_calc_d_ino(rdd, p)) p->ino = 0; + p->is_upper = rdd->is_upper; p->is_whiteout = false; if (d_type == DT_CHR) { @@ -316,21 +318,37 @@ static inline int ovl_dir_read(struct path *realpath, return err; } +/* + * Can we iterate real dir directly? + * + * Non-merge dir may contain whiteouts from a time it was a merge upper, before + * lower dir was removed under it and possibly before it was rotated from upper + * to lower layer. + */ +static bool ovl_dir_is_real(struct dentry *dir) +{ + return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir)); +} + static void ovl_dir_reset(struct file *file) { struct ovl_dir_file *od = file->private_data; struct ovl_dir_cache *cache = od->cache; struct dentry *dentry = file->f_path.dentry; - enum ovl_path_type type = ovl_path_type(dentry); + bool is_real; if (cache && ovl_dentry_version_get(dentry) != cache->version) { ovl_cache_put(od, dentry); od->cache = NULL; od->cursor = NULL; } - WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type)); - if (od->is_real && OVL_TYPE_MERGE(type)) + is_real = ovl_dir_is_real(dentry); + if (od->is_real != is_real) { + /* is_real can only become false when dir is copied up */ + if (WARN_ON(is_real)) + return; od->is_real = false; + } } static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list, @@ -816,7 +834,7 @@ static int ovl_dir_open(struct inode *inode, struct file *file) return PTR_ERR(realfile); } od->realfile = realfile; - od->is_real = !OVL_TYPE_MERGE(type); + od->is_real = ovl_dir_is_real(file->f_path.dentry); od->is_upper = OVL_TYPE_UPPER(type); file->private_data = od; @@ -835,7 +853,7 @@ const struct file_operations ovl_dir_operations = { int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) { int err; - struct ovl_cache_entry *p; + struct ovl_cache_entry *p, *n; struct rb_root root = RB_ROOT; err = ovl_dir_read_merged(dentry, list, &root); @@ -844,18 +862,29 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) err = 0; - list_for_each_entry(p, list, l_node) { - if (p->is_whiteout) - continue; + list_for_each_entry_safe(p, n, list, l_node) { + /* + * Select whiteouts in upperdir, they should + * be cleared when deleting this directory. + */ + if (p->is_whiteout) { + if (p->is_upper) + continue; + goto del_entry; + } if (p->name[0] == '.') { if (p->len == 1) - continue; + goto del_entry; if (p->len == 2 && p->name[1] == '.') - continue; + goto del_entry; } err = -ENOTEMPTY; break; + +del_entry: + list_del(&p->l_node); + kfree(p); } return err; @@ -869,7 +898,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list) list_for_each_entry(p, list, l_node) { struct dentry *dentry; - if (!p->is_whiteout) + if (WARN_ON(!p->is_whiteout || !p->is_upper)) continue; dentry = lookup_one_len(p->name, upper, p->len); @@ -985,7 +1014,7 @@ void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, } int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, - struct path *lowerstack, unsigned int numlower) + struct ovl_path *lower, unsigned int numlower) { int err; struct dentry *index = NULL; @@ -1020,7 +1049,7 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, index = NULL; break; } - err = ovl_verify_index(index, lowerstack, numlower); + err = ovl_verify_index(index, lower, numlower); /* Cleanup stale and orphan index entries */ if (err && (err == -ESTALE || err == -ENOENT)) err = ovl_cleanup(dir, index); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index f5738e96a052..be03578181d2 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -18,7 +18,6 @@ #include #include #include "overlayfs.h" -#include "ovl_entry.h" MODULE_AUTHOR("Miklos Szeredi "); MODULE_DESCRIPTION("Overlay filesystem"); @@ -39,15 +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); } } @@ -207,39 +211,48 @@ static void ovl_destroy_inode(struct inode *inode) call_rcu(&inode->i_rcu, ovl_i_callback); } -static void ovl_put_super(struct super_block *sb) +static void ovl_free_fs(struct ovl_fs *ofs) { - struct ovl_fs *ufs = sb->s_fs_info; unsigned i; - dput(ufs->indexdir); - dput(ufs->workdir); - if (ufs->workdir_locked) - ovl_inuse_unlock(ufs->workbasedir); - dput(ufs->workbasedir); - if (ufs->upper_mnt && ufs->upperdir_locked) - ovl_inuse_unlock(ufs->upper_mnt->mnt_root); - mntput(ufs->upper_mnt); - for (i = 0; i < ufs->numlower; i++) - mntput(ufs->lower_mnt[i]); - kfree(ufs->lower_mnt); + dput(ofs->indexdir); + dput(ofs->workdir); + if (ofs->workdir_locked) + ovl_inuse_unlock(ofs->workbasedir); + dput(ofs->workbasedir); + if (ofs->upperdir_locked) + ovl_inuse_unlock(ofs->upper_mnt->mnt_root); + mntput(ofs->upper_mnt); + for (i = 0; i < ofs->numlower; i++) { + mntput(ofs->lower_layers[i].mnt); + free_anon_bdev(ofs->lower_layers[i].pseudo_dev); + } + kfree(ofs->lower_layers); - kfree(ufs->config.lowerdir); - kfree(ufs->config.upperdir); - kfree(ufs->config.workdir); - put_cred(ufs->creator_cred); - kfree(ufs); + kfree(ofs->config.lowerdir); + kfree(ofs->config.upperdir); + kfree(ofs->config.workdir); + if (ofs->creator_cred) + put_cred(ofs->creator_cred); + kfree(ofs); +} + +static void ovl_put_super(struct super_block *sb) +{ + struct ovl_fs *ofs = sb->s_fs_info; + + ovl_free_fs(ofs); } static int ovl_sync_fs(struct super_block *sb, int wait) { - struct ovl_fs *ufs = sb->s_fs_info; + struct ovl_fs *ofs = sb->s_fs_info; struct super_block *upper_sb; int ret; - if (!ufs->upper_mnt) + if (!ofs->upper_mnt) return 0; - upper_sb = ufs->upper_mnt->mnt_sb; + upper_sb = ofs->upper_mnt->mnt_sb; if (!upper_sb->s_op->sync_fs) return 0; @@ -277,9 +290,9 @@ static int ovl_statfs(struct dentry *dentry, struct kstatfs *buf) } /* Will this overlay be forced to mount/remount ro? */ -static bool ovl_force_readonly(struct ovl_fs *ufs) +static bool ovl_force_readonly(struct ovl_fs *ofs) { - return (!ufs->upper_mnt || !ufs->workdir); + return (!ofs->upper_mnt || !ofs->workdir); } /** @@ -291,29 +304,29 @@ static bool ovl_force_readonly(struct ovl_fs *ufs) static int ovl_show_options(struct seq_file *m, struct dentry *dentry) { struct super_block *sb = dentry->d_sb; - struct ovl_fs *ufs = sb->s_fs_info; + struct ovl_fs *ofs = sb->s_fs_info; - seq_show_option(m, "lowerdir", ufs->config.lowerdir); - if (ufs->config.upperdir) { - seq_show_option(m, "upperdir", ufs->config.upperdir); - seq_show_option(m, "workdir", ufs->config.workdir); + seq_show_option(m, "lowerdir", ofs->config.lowerdir); + if (ofs->config.upperdir) { + seq_show_option(m, "upperdir", ofs->config.upperdir); + seq_show_option(m, "workdir", ofs->config.workdir); } - if (ufs->config.default_permissions) + if (ofs->config.default_permissions) seq_puts(m, ",default_permissions"); - if (ufs->config.redirect_dir != ovl_redirect_dir_def) + if (ofs->config.redirect_dir != ovl_redirect_dir_def) seq_printf(m, ",redirect_dir=%s", - ufs->config.redirect_dir ? "on" : "off"); - if (ufs->config.index != ovl_index_def) + ofs->config.redirect_dir ? "on" : "off"); + if (ofs->config.index != ovl_index_def) seq_printf(m, ",index=%s", - ufs->config.index ? "on" : "off"); + ofs->config.index ? "on" : "off"); return 0; } static int ovl_remount(struct super_block *sb, int *flags, char *data) { - struct ovl_fs *ufs = sb->s_fs_info; + struct ovl_fs *ofs = sb->s_fs_info; - if (!(*flags & MS_RDONLY) && ovl_force_readonly(ufs)) + if (!(*flags & MS_RDONLY) && ovl_force_readonly(ofs)) return -EROFS; return 0; @@ -451,13 +464,11 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config) #define OVL_WORKDIR_NAME "work" #define OVL_INDEXDIR_NAME "index" -static struct dentry *ovl_workdir_create(struct super_block *sb, - struct ovl_fs *ufs, - struct dentry *dentry, +static struct dentry *ovl_workdir_create(struct ovl_fs *ofs, const char *name, bool persist) { - struct inode *dir = dentry->d_inode; - struct vfsmount *mnt = ufs->upper_mnt; + struct inode *dir = ofs->workbasedir->d_inode; + struct vfsmount *mnt = ofs->upper_mnt; struct dentry *work; int err; bool retried = false; @@ -471,7 +482,7 @@ static struct dentry *ovl_workdir_create(struct super_block *sb, locked = true; retry: - work = lookup_one_len(name, dentry, strlen(name)); + work = lookup_one_len(name, ofs->workbasedir, strlen(name)); if (!IS_ERR(work)) { struct iattr attr = { @@ -541,8 +552,7 @@ out_dput: dput(work); out_err: pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n", - ufs->config.workdir, name, -err); - sb->s_flags |= MS_RDONLY; + ofs->config.workdir, name, -err); work = NULL; goto out_unlock; } @@ -585,7 +595,7 @@ static int ovl_mount_dir_noesc(const char *name, struct path *path) return 0; out_put: - path_put(path); + path_put_init(path); out: return err; } @@ -603,7 +613,7 @@ static int ovl_mount_dir(const char *name, struct path *path) if (ovl_dentry_remote(path->dentry)) { pr_err("overlayfs: filesystem on '%s' not supported as upperdir\n", tmp); - path_put(path); + path_put_init(path); err = -EINVAL; } kfree(tmp); @@ -655,7 +665,7 @@ static int ovl_lower_dir(const char *name, struct path *path, return 0; out_put: - path_put(path); + path_put_init(path); out: return err; } @@ -826,129 +836,269 @@ static const struct xattr_handler *ovl_xattr_handlers[] = { NULL }; -static int ovl_fill_super(struct super_block *sb, void *data, int silent) +static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath) { - struct path upperpath = { }; - struct path workpath = { }; - struct dentry *root_dentry; - struct ovl_entry *oe; - struct ovl_fs *ufs; - struct path *stack = NULL; - char *lowertmp; - char *lower; - unsigned int numlower; - unsigned int stacklen = 0; - unsigned int i; - bool remote = false; - struct cred *cred; + struct vfsmount *upper_mnt; int err; - err = -ENOMEM; - ufs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); - if (!ufs) + err = ovl_mount_dir(ofs->config.upperdir, upperpath); + if (err) goto out; - ufs->config.redirect_dir = ovl_redirect_dir_def; - ufs->config.index = ovl_index_def; - err = ovl_parse_opt((char *) data, &ufs->config); + /* Upper fs should not be r/o */ + if (sb_rdonly(upperpath->mnt->mnt_sb)) { + pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n"); + err = -EINVAL; + goto out; + } + + err = ovl_check_namelen(upperpath, ofs, ofs->config.upperdir); if (err) - goto out_free_config; + goto out; + + err = -EBUSY; + if (ovl_inuse_trylock(upperpath->dentry)) { + ofs->upperdir_locked = true; + } else if (ofs->config.index) { + pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n"); + goto out; + } else { + pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n"); + } + + upper_mnt = clone_private_mount(upperpath); + err = PTR_ERR(upper_mnt); + if (IS_ERR(upper_mnt)) { + pr_err("overlayfs: failed to clone upperpath\n"); + goto out; + } + + /* Don't inherit atime flags */ + upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME); + ofs->upper_mnt = upper_mnt; + err = 0; +out: + return err; +} + +static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath) +{ + struct dentry *temp; + int err; + + ofs->workdir = ovl_workdir_create(ofs, OVL_WORKDIR_NAME, false); + if (!ofs->workdir) + return 0; + + /* + * Upper should support d_type, else whiteouts are visible. Given + * workdir and upper are on same fs, we can do iterate_dir() on + * workdir. This check requires successful creation of workdir in + * previous step. + */ + err = ovl_check_d_type_supported(workpath); + if (err < 0) + return err; + + /* + * We allowed this configuration and don't want to break users over + * kernel upgrade. So warn instead of erroring out. + */ + if (!err) + pr_warn("overlayfs: upper fs needs to support d_type.\n"); + + /* Check if upper/work fs supports O_TMPFILE */ + temp = ovl_do_tmpfile(ofs->workdir, S_IFREG | 0); + ofs->tmpfile = !IS_ERR(temp); + if (ofs->tmpfile) + dput(temp); + else + pr_warn("overlayfs: upper fs does not support tmpfile.\n"); + + /* + * Check if upper/work fs supports trusted.overlay.* xattr + */ + err = ovl_do_setxattr(ofs->workdir, OVL_XATTR_OPAQUE, "0", 1, 0); + if (err) { + ofs->noxattr = true; + pr_warn("overlayfs: upper fs does not support xattr.\n"); + } else { + vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE); + } + + /* Check if upper/work fs supports file handles */ + if (ofs->config.index && + !ovl_can_decode_fh(ofs->workdir->d_sb)) { + ofs->config.index = false; + pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n"); + } + + return 0; +} + +static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath) +{ + int err; + struct path workpath = { }; + + err = ovl_mount_dir(ofs->config.workdir, &workpath); + if (err) + goto out; err = -EINVAL; - if (!ufs->config.lowerdir) { - if (!silent) - pr_err("overlayfs: missing 'lowerdir'\n"); - goto out_free_config; + if (upperpath->mnt != workpath.mnt) { + pr_err("overlayfs: workdir and upperdir must reside under the same mount\n"); + goto out; + } + if (!ovl_workdir_ok(workpath.dentry, upperpath->dentry)) { + pr_err("overlayfs: workdir and upperdir must be separate subtrees\n"); + goto out; } - sb->s_stack_depth = 0; - sb->s_maxbytes = MAX_LFS_FILESIZE; - if (ufs->config.upperdir) { - if (!ufs->config.workdir) { - pr_err("overlayfs: missing 'workdir'\n"); - goto out_free_config; - } - - err = ovl_mount_dir(ufs->config.upperdir, &upperpath); - if (err) - goto out_free_config; - - /* Upper fs should not be r/o */ - if (sb_rdonly(upperpath.mnt->mnt_sb)) { - pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n"); - err = -EINVAL; - goto out_put_upperpath; - } - - err = ovl_check_namelen(&upperpath, ufs, ufs->config.upperdir); - if (err) - goto out_put_upperpath; - - err = -EBUSY; - if (ovl_inuse_trylock(upperpath.dentry)) { - ufs->upperdir_locked = true; - } else if (ufs->config.index) { - pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n"); - goto out_put_upperpath; - } else { - pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n"); - } - - err = ovl_mount_dir(ufs->config.workdir, &workpath); - if (err) - goto out_unlock_upperdentry; - - err = -EINVAL; - if (upperpath.mnt != workpath.mnt) { - pr_err("overlayfs: workdir and upperdir must reside under the same mount\n"); - goto out_put_workpath; - } - if (!ovl_workdir_ok(workpath.dentry, upperpath.dentry)) { - pr_err("overlayfs: workdir and upperdir must be separate subtrees\n"); - goto out_put_workpath; - } - - err = -EBUSY; - if (ovl_inuse_trylock(workpath.dentry)) { - ufs->workdir_locked = true; - } else if (ufs->config.index) { - pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n"); - goto out_put_workpath; - } else { - pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n"); - } - - ufs->workbasedir = workpath.dentry; - sb->s_stack_depth = upperpath.mnt->mnt_sb->s_stack_depth; + err = -EBUSY; + if (ovl_inuse_trylock(workpath.dentry)) { + ofs->workdir_locked = true; + } else if (ofs->config.index) { + pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n"); + goto out; + } else { + pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n"); } + + ofs->workbasedir = dget(workpath.dentry); + err = ovl_make_workdir(ofs, &workpath); + if (err) + goto out; + + err = 0; +out: + path_put(&workpath); + + return err; +} + +static int ovl_get_indexdir(struct ovl_fs *ofs, struct ovl_entry *oe, + struct path *upperpath) +{ + int err; + + /* Verify lower root is upper root origin */ + err = ovl_verify_origin(upperpath->dentry, oe->lowerstack[0].dentry, + false, true); + if (err) { + pr_err("overlayfs: failed to verify upper root origin\n"); + goto out; + } + + ofs->indexdir = ovl_workdir_create(ofs, OVL_INDEXDIR_NAME, true); + if (ofs->indexdir) { + /* Verify upper root is index dir origin */ + err = ovl_verify_origin(ofs->indexdir, upperpath->dentry, + true, true); + if (err) + pr_err("overlayfs: failed to verify index dir origin\n"); + + /* Cleanup bad/stale/orphan index entries */ + if (!err) + err = ovl_indexdir_cleanup(ofs->indexdir, + ofs->upper_mnt, + oe->lowerstack, + oe->numlower); + } + if (err || !ofs->indexdir) + pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n"); + +out: + return err; +} + +static int ovl_get_lower_layers(struct ovl_fs *ofs, struct path *stack, + unsigned int numlower) +{ + int err; + unsigned int i; + err = -ENOMEM; - lowertmp = kstrdup(ufs->config.lowerdir, GFP_KERNEL); + ofs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer), + GFP_KERNEL); + if (ofs->lower_layers == NULL) + goto out; + for (i = 0; i < numlower; i++) { + struct vfsmount *mnt; + dev_t dev; + + err = get_anon_bdev(&dev); + if (err) { + pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n"); + goto out; + } + + mnt = clone_private_mount(&stack[i]); + err = PTR_ERR(mnt); + if (IS_ERR(mnt)) { + pr_err("overlayfs: failed to clone lowerpath\n"); + free_anon_bdev(dev); + goto out; + } + /* + * Make lower layers R/O. That way fchmod/fchown on lower file + * will fail instead of modifying lower fs. + */ + mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME; + + ofs->lower_layers[ofs->numlower].mnt = mnt; + ofs->lower_layers[ofs->numlower].pseudo_dev = dev; + ofs->numlower++; + + /* Check if all lower layers are on same sb */ + if (i == 0) + ofs->same_sb = mnt->mnt_sb; + else if (ofs->same_sb != mnt->mnt_sb) + ofs->same_sb = NULL; + } + err = 0; +out: + return err; +} + +static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb, + struct ovl_fs *ofs) +{ + int err; + char *lowertmp, *lower; + struct path *stack = NULL; + unsigned int stacklen, numlower = 0, i; + bool remote = false; + struct ovl_entry *oe; + + err = -ENOMEM; + lowertmp = kstrdup(ofs->config.lowerdir, GFP_KERNEL); if (!lowertmp) - goto out_unlock_workdentry; + 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_free_lowertmp; - } else if (!ufs->config.upperdir && stacklen == 1) { + goto out_err; + } else if (!ofs->config.upperdir && stacklen == 1) { pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n"); - goto out_free_lowertmp; + goto out_err; } err = -ENOMEM; stack = kcalloc(stacklen, sizeof(struct path), GFP_KERNEL); if (!stack) - goto out_free_lowertmp; + goto out_err; err = -EINVAL; lower = lowertmp; for (numlower = 0; numlower < stacklen; numlower++) { - err = ovl_lower_dir(lower, &stack[numlower], ufs, + err = ovl_lower_dir(lower, &stack[numlower], ofs, &sb->s_stack_depth, &remote); if (err) - goto out_put_lowerpath; + goto out_err; lower = strchr(lower, '\0') + 1; } @@ -957,190 +1107,144 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) sb->s_stack_depth++; if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) { pr_err("overlayfs: maximum fs stacking depth exceeded\n"); - goto out_put_lowerpath; + goto out_err; } - if (ufs->config.upperdir) { - ufs->upper_mnt = clone_private_mount(&upperpath); - err = PTR_ERR(ufs->upper_mnt); - if (IS_ERR(ufs->upper_mnt)) { - pr_err("overlayfs: failed to clone upperpath\n"); - goto out_put_lowerpath; - } - - /* Don't inherit atime flags */ - ufs->upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME); - - sb->s_time_gran = ufs->upper_mnt->mnt_sb->s_time_gran; - - ufs->workdir = ovl_workdir_create(sb, ufs, workpath.dentry, - OVL_WORKDIR_NAME, false); - /* - * Upper should support d_type, else whiteouts are visible. - * Given workdir and upper are on same fs, we can do - * iterate_dir() on workdir. This check requires successful - * creation of workdir in previous step. - */ - if (ufs->workdir) { - struct dentry *temp; - - err = ovl_check_d_type_supported(&workpath); - if (err < 0) - goto out_put_workdir; - - /* - * We allowed this configuration and don't want to - * break users over kernel upgrade. So warn instead - * of erroring out. - */ - if (!err) - pr_warn("overlayfs: upper fs needs to support d_type.\n"); - - /* Check if upper/work fs supports O_TMPFILE */ - temp = ovl_do_tmpfile(ufs->workdir, S_IFREG | 0); - ufs->tmpfile = !IS_ERR(temp); - if (ufs->tmpfile) - dput(temp); - else - pr_warn("overlayfs: upper fs does not support tmpfile.\n"); - - /* - * Check if upper/work fs supports trusted.overlay.* - * xattr - */ - err = ovl_do_setxattr(ufs->workdir, OVL_XATTR_OPAQUE, - "0", 1, 0); - if (err) { - ufs->noxattr = true; - pr_warn("overlayfs: upper fs does not support xattr.\n"); - } else { - vfs_removexattr(ufs->workdir, OVL_XATTR_OPAQUE); - } - - /* Check if upper/work fs supports file handles */ - if (ufs->config.index && - !ovl_can_decode_fh(ufs->workdir->d_sb)) { - ufs->config.index = false; - pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n"); - } - } - } + err = ovl_get_lower_layers(ofs, stack, numlower); + if (err) + goto out_err; err = -ENOMEM; - ufs->lower_mnt = kcalloc(numlower, sizeof(struct vfsmount *), GFP_KERNEL); - if (ufs->lower_mnt == NULL) - goto out_put_workdir; + oe = ovl_alloc_entry(numlower); + if (!oe) + goto out_err; + for (i = 0; i < numlower; i++) { - struct vfsmount *mnt = clone_private_mount(&stack[i]); - - err = PTR_ERR(mnt); - if (IS_ERR(mnt)) { - pr_err("overlayfs: failed to clone lowerpath\n"); - goto out_put_lower_mnt; - } - /* - * Make lower_mnt R/O. That way fchmod/fchown on lower file - * will fail instead of modifying lower fs. - */ - mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME; - - ufs->lower_mnt[ufs->numlower] = mnt; - ufs->numlower++; - - /* Check if all lower layers are on same sb */ - if (i == 0) - ufs->same_sb = mnt->mnt_sb; - else if (ufs->same_sb != mnt->mnt_sb) - ufs->same_sb = NULL; + oe->lowerstack[i].dentry = dget(stack[i].dentry); + oe->lowerstack[i].layer = &ofs->lower_layers[i]; } - /* If the upper fs is nonexistent, we mark overlayfs r/o too */ - if (!ufs->upper_mnt) - sb->s_flags |= MS_RDONLY; - else if (ufs->upper_mnt->mnt_sb != ufs->same_sb) - ufs->same_sb = NULL; - - if (!(ovl_force_readonly(ufs)) && ufs->config.index) { - /* Verify lower root is upper root origin */ - err = ovl_verify_origin(upperpath.dentry, ufs->lower_mnt[0], - stack[0].dentry, false, true); - if (err) { - pr_err("overlayfs: failed to verify upper root origin\n"); - goto out_put_lower_mnt; - } - - ufs->indexdir = ovl_workdir_create(sb, ufs, workpath.dentry, - OVL_INDEXDIR_NAME, true); - if (ufs->indexdir) { - /* Verify upper root is index dir origin */ - err = ovl_verify_origin(ufs->indexdir, ufs->upper_mnt, - upperpath.dentry, true, true); - if (err) - pr_err("overlayfs: failed to verify index dir origin\n"); - - /* Cleanup bad/stale/orphan index entries */ - if (!err) - err = ovl_indexdir_cleanup(ufs->indexdir, - ufs->upper_mnt, - stack, numlower); - } - if (err || !ufs->indexdir) - pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n"); - if (err) - goto out_put_indexdir; - } - - /* Show index=off/on in /proc/mounts for any of the reasons above */ - if (!ufs->indexdir) - ufs->config.index = false; - if (remote) sb->s_d_op = &ovl_reval_dentry_operations; else sb->s_d_op = &ovl_dentry_operations; +out: + for (i = 0; i < numlower; i++) + path_put(&stack[i]); + kfree(stack); + kfree(lowertmp); + + return oe; + +out_err: + oe = ERR_PTR(err); + goto out; +} + +static int ovl_fill_super(struct super_block *sb, void *data, int silent) +{ + struct path upperpath = { }; + struct dentry *root_dentry; + struct ovl_entry *oe; + struct ovl_fs *ofs; + struct cred *cred; + int err; + err = -ENOMEM; - ufs->creator_cred = cred = prepare_creds(); + ofs = kzalloc(sizeof(struct ovl_fs), GFP_KERNEL); + if (!ofs) + goto out; + + ofs->creator_cred = cred = prepare_creds(); if (!cred) - goto out_put_indexdir; + goto out_err; + + ofs->config.redirect_dir = ovl_redirect_dir_def; + ofs->config.index = ovl_index_def; + err = ovl_parse_opt((char *) data, &ofs->config); + if (err) + goto out_err; + + err = -EINVAL; + if (!ofs->config.lowerdir) { + if (!silent) + pr_err("overlayfs: missing 'lowerdir'\n"); + goto out_err; + } + + sb->s_stack_depth = 0; + sb->s_maxbytes = MAX_LFS_FILESIZE; + if (ofs->config.upperdir) { + if (!ofs->config.workdir) { + pr_err("overlayfs: missing 'workdir'\n"); + goto out_err; + } + + err = ovl_get_upper(ofs, &upperpath); + if (err) + goto out_err; + + err = ovl_get_workdir(ofs, &upperpath); + if (err) + goto out_err; + + if (!ofs->workdir) + sb->s_flags |= MS_RDONLY; + + sb->s_stack_depth = ofs->upper_mnt->mnt_sb->s_stack_depth; + sb->s_time_gran = ofs->upper_mnt->mnt_sb->s_time_gran; + + } + oe = ovl_get_lowerstack(sb, ofs); + err = PTR_ERR(oe); + if (IS_ERR(oe)) + goto out_err; + + /* If the upper fs is nonexistent, we mark overlayfs r/o too */ + if (!ofs->upper_mnt) + sb->s_flags |= MS_RDONLY; + else if (ofs->upper_mnt->mnt_sb != ofs->same_sb) + ofs->same_sb = NULL; + + if (!(ovl_force_readonly(ofs)) && ofs->config.index) { + err = ovl_get_indexdir(ofs, oe, &upperpath); + if (err) + goto out_free_oe; + + if (!ofs->indexdir) + sb->s_flags |= MS_RDONLY; + } + + /* Show index=off/on in /proc/mounts for any of the reasons above */ + if (!ofs->indexdir) + ofs->config.index = false; /* Never override disk quota limits or use reserved space */ cap_lower(cred->cap_effective, CAP_SYS_RESOURCE); - err = -ENOMEM; - oe = ovl_alloc_entry(numlower); - if (!oe) - goto out_put_cred; - sb->s_magic = OVERLAYFS_SUPER_MAGIC; sb->s_op = &ovl_super_operations; sb->s_xattr = ovl_xattr_handlers; - sb->s_fs_info = ufs; + sb->s_fs_info = ofs; sb->s_flags |= MS_POSIXACL | MS_NOREMOTELOCK; + err = -ENOMEM; root_dentry = d_make_root(ovl_new_inode(sb, S_IFDIR, 0)); if (!root_dentry) goto out_free_oe; mntput(upperpath.mnt); - for (i = 0; i < numlower; i++) - mntput(stack[i].mnt); - mntput(workpath.mnt); - kfree(lowertmp); - if (upperpath.dentry) { oe->has_upper = true; if (ovl_is_impuredir(upperpath.dentry)) ovl_set_flag(OVL_IMPURE, d_inode(root_dentry)); } - for (i = 0; i < numlower; i++) { - oe->lowerstack[i].dentry = stack[i].dentry; - oe->lowerstack[i].mnt = ufs->lower_mnt[i]; - } - kfree(stack); root_dentry->d_fsdata = oe; + /* Root is always merge -> can have whiteouts */ + ovl_set_flag(OVL_WHITEOUTS, d_inode(root_dentry)); ovl_inode_init(d_inode(root_dentry), upperpath.dentry, ovl_dentry_lower(root_dentry)); @@ -1149,39 +1253,11 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) return 0; out_free_oe: + ovl_entry_stack_free(oe); kfree(oe); -out_put_cred: - put_cred(ufs->creator_cred); -out_put_indexdir: - dput(ufs->indexdir); -out_put_lower_mnt: - for (i = 0; i < ufs->numlower; i++) - mntput(ufs->lower_mnt[i]); - kfree(ufs->lower_mnt); -out_put_workdir: - dput(ufs->workdir); - mntput(ufs->upper_mnt); -out_put_lowerpath: - for (i = 0; i < numlower; i++) - path_put(&stack[i]); - kfree(stack); -out_free_lowertmp: - kfree(lowertmp); -out_unlock_workdentry: - if (ufs->workdir_locked) - ovl_inuse_unlock(workpath.dentry); -out_put_workpath: - path_put(&workpath); -out_unlock_upperdentry: - if (ufs->upperdir_locked) - ovl_inuse_unlock(upperpath.dentry); -out_put_upperpath: +out_err: path_put(&upperpath); -out_free_config: - kfree(ufs->config.lowerdir); - kfree(ufs->config.upperdir); - kfree(ufs->config.workdir); - kfree(ufs); + ovl_free_fs(ofs); out: return err; } diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index b9b239fa5cfd..d6bb1c9f5e7a 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -17,7 +17,6 @@ #include #include #include "overlayfs.h" -#include "ovl_entry.h" int ovl_want_write(struct dentry *dentry) { @@ -125,7 +124,12 @@ void ovl_path_lower(struct dentry *dentry, struct path *path) { struct ovl_entry *oe = dentry->d_fsdata; - *path = oe->numlower ? oe->lowerstack[0] : (struct path) { }; + if (oe->numlower) { + path->mnt = oe->lowerstack[0].layer->mnt; + path->dentry = oe->lowerstack[0].dentry; + } else { + *path = (struct path) { }; + } } enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) @@ -329,6 +333,19 @@ void ovl_copy_up_end(struct dentry *dentry) mutex_unlock(&OVL_I(d_inode(dentry))->lock); } +bool ovl_check_origin_xattr(struct dentry *dentry) +{ + int res; + + res = vfs_getxattr(dentry, OVL_XATTR_ORIGIN, NULL, 0); + + /* Zero size value means "copied up but origin unknown" */ + if (res >= 0) + return true; + + return false; +} + bool ovl_check_dir_xattr(struct dentry *dentry, const char *name) { int res; diff --git a/include/linux/path.h b/include/linux/path.h index 81e65a5be7ce..475225a03d0d 100644 --- a/include/linux/path.h +++ b/include/linux/path.h @@ -18,4 +18,10 @@ static inline int path_equal(const struct path *path1, const struct path *path2) return path1->mnt == path2->mnt && path1->dentry == path2->dentry; } +static inline void path_put_init(struct path *path) +{ + path_put(path); + *path = (struct path) { }; +} + #endif /* _LINUX_PATH_H */