diff options
Diffstat (limited to 'fs/overlayfs')
| -rw-r--r-- | fs/overlayfs/copy_up.c | 2 | ||||
| -rw-r--r-- | fs/overlayfs/dir.c | 35 | ||||
| -rw-r--r-- | fs/overlayfs/inode.c | 46 | ||||
| -rw-r--r-- | fs/overlayfs/namei.c | 53 | ||||
| -rw-r--r-- | fs/overlayfs/overlayfs.h | 18 | ||||
| -rw-r--r-- | fs/overlayfs/readdir.c | 392 | ||||
| -rw-r--r-- | fs/overlayfs/super.c | 24 | ||||
| -rw-r--r-- | fs/overlayfs/util.c | 31 |
8 files changed, 493 insertions, 108 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index acb6f97..aad97b3 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -241,7 +241,7 @@ struct ovl_fh *ovl_encode_fh(struct dentry *lower, bool is_upper) int buflen = MAX_HANDLE_SZ; uuid_t *uuid = &lower->d_sb->s_uuid; - buf = kmalloc(buflen, GFP_TEMPORARY); + buf = kmalloc(buflen, GFP_KERNEL); if (!buf) return ERR_PTR(-ENOMEM); diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 641d9ee..3309b19 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -155,7 +155,7 @@ static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) static void ovl_instantiate(struct dentry *dentry, struct inode *inode, struct dentry *newdentry, bool hardlink) { - ovl_dentry_version_inc(dentry->d_parent); + ovl_dentry_version_inc(dentry->d_parent, false); ovl_dentry_set_upper_alias(dentry); if (!hardlink) { ovl_inode_update(inode, newdentry); @@ -481,17 +481,30 @@ out_cleanup: } static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, - struct cattr *attr, struct dentry *hardlink) + struct cattr *attr, struct dentry *hardlink, + bool origin) { int err; const struct cred *old_cred; struct cred *override_cred; + struct dentry *parent = dentry->d_parent; - err = ovl_copy_up(dentry->d_parent); + err = ovl_copy_up(parent); if (err) return err; old_cred = ovl_override_creds(dentry->d_sb); + + /* + * When linking a file with copy up origin into a new parent, mark the + * new parent dir "impure". + */ + if (origin) { + err = ovl_set_impure(parent, ovl_dentry_upper(parent)); + if (err) + goto out_revert_creds; + } + err = -ENOMEM; override_cred = prepare_creds(); if (override_cred) { @@ -550,7 +563,7 @@ static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, inode_init_owner(inode, dentry->d_parent->d_inode, mode); attr.mode = inode->i_mode; - err = ovl_create_or_link(dentry, inode, &attr, NULL); + err = ovl_create_or_link(dentry, inode, &attr, NULL, false); if (err) iput(inode); @@ -609,7 +622,8 @@ static int ovl_link(struct dentry *old, struct inode *newdir, inode = d_inode(old); ihold(inode); - err = ovl_create_or_link(new, inode, NULL, ovl_dentry_upper(old)); + err = ovl_create_or_link(new, inode, NULL, ovl_dentry_upper(old), + ovl_type_origin(old)); if (err) iput(inode); @@ -678,7 +692,7 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir) if (flags) ovl_cleanup(wdir, upper); - ovl_dentry_version_inc(dentry->d_parent); + ovl_dentry_version_inc(dentry->d_parent, true); out_d_drop: d_drop(dentry); dput(whiteout); @@ -728,7 +742,7 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) err = vfs_rmdir(dir, upper); else err = vfs_unlink(dir, upper, NULL); - ovl_dentry_version_inc(dentry->d_parent); + ovl_dentry_version_inc(dentry->d_parent, ovl_type_origin(dentry)); /* * Keeping this dentry hashed would mean having to release @@ -819,7 +833,7 @@ static char *ovl_get_redirect(struct dentry *dentry, bool samedir) goto out; } - buf = ret = kmalloc(buflen, GFP_TEMPORARY); + buf = ret = kmalloc(buflen, GFP_KERNEL); if (!buf) goto out; @@ -1075,8 +1089,9 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, drop_nlink(d_inode(new)); } - ovl_dentry_version_inc(old->d_parent); - ovl_dentry_version_inc(new->d_parent); + ovl_dentry_version_inc(old->d_parent, + !overwrite && ovl_type_origin(new)); + ovl_dentry_version_inc(new->d_parent, ovl_type_origin(old)); out_dput: dput(newdentry); diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 69f4fc2..a619add 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -202,37 +202,38 @@ bool ovl_is_private_xattr(const char *name) sizeof(OVL_XATTR_PREFIX) - 1) == 0; } -int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value, - size_t size, int flags) +int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, + const void *value, size_t size, int flags) { int err; - struct path realpath; - enum ovl_path_type type = ovl_path_real(dentry, &realpath); + struct dentry *upperdentry = ovl_i_dentry_upper(inode); + struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry); const struct cred *old_cred; err = ovl_want_write(dentry); if (err) goto out; - if (!value && !OVL_TYPE_UPPER(type)) { - err = vfs_getxattr(realpath.dentry, name, NULL, 0); + if (!value && !upperdentry) { + err = vfs_getxattr(realdentry, name, NULL, 0); if (err < 0) goto out_drop_write; } - err = ovl_copy_up(dentry); - if (err) - goto out_drop_write; + if (!upperdentry) { + err = ovl_copy_up(dentry); + if (err) + goto out_drop_write; - if (!OVL_TYPE_UPPER(type)) - ovl_path_upper(dentry, &realpath); + realdentry = ovl_dentry_upper(dentry); + } old_cred = ovl_override_creds(dentry->d_sb); if (value) - err = vfs_setxattr(realpath.dentry, name, value, size, flags); + err = vfs_setxattr(realdentry, name, value, size, flags); else { WARN_ON(flags != XATTR_REPLACE); - err = vfs_removexattr(realpath.dentry, name); + err = vfs_removexattr(realdentry, name); } revert_creds(old_cred); @@ -242,12 +243,13 @@ out: return err; } -int ovl_xattr_get(struct dentry *dentry, const char *name, +int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, void *value, size_t size) { - struct dentry *realdentry = ovl_dentry_real(dentry); ssize_t res; const struct cred *old_cred; + struct dentry *realdentry = + ovl_i_dentry_upper(inode) ?: ovl_dentry_lower(dentry); old_cred = ovl_override_creds(dentry->d_sb); res = vfs_getxattr(realdentry, name, value, size); @@ -496,6 +498,9 @@ static int ovl_set_nlink_common(struct dentry *dentry, len = snprintf(buf, sizeof(buf), format, (int) (inode->i_nlink - realinode->i_nlink)); + if (WARN_ON(len >= sizeof(buf))) + return -EIO; + return ovl_do_setxattr(ovl_dentry_upper(dentry), OVL_XATTR_NLINK, buf, len, 0); } @@ -574,10 +579,13 @@ static int ovl_inode_set(struct inode *inode, void *data) static bool ovl_verify_inode(struct inode *inode, struct dentry *lowerdentry, struct dentry *upperdentry) { - struct inode *lowerinode = lowerdentry ? d_inode(lowerdentry) : NULL; - - /* Lower (origin) inode must match, even if NULL */ - if (ovl_inode_lower(inode) != lowerinode) + /* + * Allow non-NULL lower inode in ovl_inode even if lowerdentry is NULL. + * This happens when finding a copied up overlay inode for a renamed + * or hardlinked overlay dentry and lower dentry cannot be followed + * by origin because lower fs does not support file handles. + */ + if (lowerdentry && ovl_inode_lower(inode) != d_inode(lowerdentry)) return false; /* diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c index 9bc0e58..c3addd1 100644 --- a/fs/overlayfs/namei.c +++ b/fs/overlayfs/namei.c @@ -38,7 +38,7 @@ static int ovl_check_redirect(struct dentry *dentry, struct ovl_lookup_data *d, return 0; goto fail; } - buf = kzalloc(prelen + res + strlen(post) + 1, GFP_TEMPORARY); + buf = kzalloc(prelen + res + strlen(post) + 1, GFP_KERNEL); if (!buf) return -ENOMEM; @@ -103,7 +103,7 @@ static struct ovl_fh *ovl_get_origin_fh(struct dentry *dentry) if (res == 0) return NULL; - fh = kzalloc(res, GFP_TEMPORARY); + fh = kzalloc(res, GFP_KERNEL); if (!fh) return ERR_PTR(-ENOMEM); @@ -309,7 +309,7 @@ static int ovl_check_origin(struct dentry *upperdentry, BUG_ON(*ctrp); if (!*stackp) - *stackp = kmalloc(sizeof(struct path), GFP_TEMPORARY); + *stackp = kmalloc(sizeof(struct path), GFP_KERNEL); if (!*stackp) { dput(origin); return -ENOMEM; @@ -397,8 +397,19 @@ int ovl_verify_index(struct dentry *index, struct path *lowerstack, if (!d_inode(index)) return 0; - err = -EISDIR; - if (d_is_dir(index)) + /* + * Directory index entries are going to be used for looking up + * redirected upper dirs by lower dir fh when decoding an overlay + * file handle of a merge dir. Whiteout index entries are going to be + * used as an indication that an exported overlay file handle should + * be treated as stale (i.e. after unlink of the overlay inode). + * We don't know the verification rules for directory and whiteout + * index entries, because they have not been implemented yet, so return + * EROFS if those entries are found to avoid corrupting an index that + * was created by a newer kernel. + */ + err = -EROFS; + if (d_is_dir(index) || ovl_is_whiteout(index)) goto fail; err = -EINVAL; @@ -407,7 +418,7 @@ int ovl_verify_index(struct dentry *index, struct path *lowerstack, err = -ENOMEM; len = index->d_name.len / 2; - fh = kzalloc(len, GFP_TEMPORARY); + fh = kzalloc(len, GFP_KERNEL); if (!fh) goto fail; @@ -436,8 +447,8 @@ out: return err; fail: - pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, err=%i)\n", - index, err); + pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, ftype=%x, err=%i)\n", + index, d_inode(index)->i_mode & S_IFMT, err); goto out; } @@ -467,7 +478,7 @@ int ovl_get_index_name(struct dentry *origin, struct qstr *name) return PTR_ERR(fh); err = -ENOMEM; - n = kzalloc(fh->len * 2, GFP_TEMPORARY); + n = kzalloc(fh->len * 2, GFP_KERNEL); if (n) { s = bin2hex(n, fh, fh->len); *name = (struct qstr) QSTR_INIT(n, s - n); @@ -502,6 +513,7 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry, goto out; } + inode = d_inode(index); if (d_is_negative(index)) { if (upper && d_inode(origin)->i_nlink > 1) { pr_warn_ratelimited("overlayfs: hard link with origin but no index (ino=%lu).\n", @@ -511,11 +523,22 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry, dput(index); index = NULL; - } else if (upper && d_inode(index) != d_inode(upper)) { - inode = d_inode(index); - pr_warn_ratelimited("overlayfs: wrong index found (index ino: %lu, upper ino: %lu).\n", - d_inode(index)->i_ino, - d_inode(upper)->i_ino); + } else if (upper && d_inode(upper) != inode) { + pr_warn_ratelimited("overlayfs: wrong index found (index=%pd2, ino=%lu, upper ino=%lu).\n", + index, inode->i_ino, d_inode(upper)->i_ino); + goto fail; + } else if (ovl_dentry_weird(index) || ovl_is_whiteout(index) || + ((inode->i_mode ^ d_inode(origin)->i_mode) & S_IFMT)) { + /* + * Index should always be of the same file type as origin + * except for the case of a whiteout index. A whiteout + * index should only exist if all lower aliases have been + * unlinked, which means that finding a lower origin on lookup + * whose index is a whiteout should be treated as an error. + */ + pr_warn_ratelimited("overlayfs: bad index found (index=%pd2, ftype=%x, origin ftype=%x).\n", + index, d_inode(index)->i_mode & S_IFMT, + d_inode(origin)->i_mode & S_IFMT); goto fail; } @@ -623,7 +646,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry, if (!d.stop && poe->numlower) { err = -ENOMEM; stack = kcalloc(ofs->numlower, sizeof(struct path), - GFP_TEMPORARY); + GFP_KERNEL); if (!stack) goto out_put_upper; } diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 60d2660..d4e8c1a 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -47,7 +47,8 @@ enum ovl_flag { /* Is the real inode encoded in fid an upper inode? */ #define OVL_FH_FLAG_PATH_UPPER (1 << 2) -#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN) +#define OVL_FH_FLAG_ALL (OVL_FH_FLAG_BIG_ENDIAN | OVL_FH_FLAG_ANY_ENDIAN | \ + OVL_FH_FLAG_PATH_UPPER) #if defined(__LITTLE_ENDIAN) #define OVL_FH_FLAG_CPU_ENDIAN 0 @@ -199,11 +200,12 @@ enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path); struct dentry *ovl_dentry_upper(struct dentry *dentry); struct dentry *ovl_dentry_lower(struct dentry *dentry); struct dentry *ovl_dentry_real(struct dentry *dentry); +struct dentry *ovl_i_dentry_upper(struct inode *inode); struct inode *ovl_inode_upper(struct inode *inode); struct inode *ovl_inode_lower(struct inode *inode); struct inode *ovl_inode_real(struct inode *inode); -struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry); -void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache); +struct ovl_dir_cache *ovl_dir_cache(struct inode *inode); +void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache); bool ovl_dentry_is_opaque(struct dentry *dentry); bool ovl_dentry_is_whiteout(struct dentry *dentry); void ovl_dentry_set_opaque(struct dentry *dentry); @@ -215,7 +217,7 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect); void ovl_inode_init(struct inode *inode, struct dentry *upperdentry, struct dentry *lowerdentry); void ovl_inode_update(struct inode *inode, struct dentry *upperdentry); -void ovl_dentry_version_inc(struct dentry *dentry); +void ovl_dentry_version_inc(struct dentry *dentry, bool impurity); u64 ovl_dentry_version_get(struct dentry *dentry); bool ovl_is_whiteout(struct dentry *dentry); struct file *ovl_path_open(struct path *path, int flags); @@ -227,6 +229,7 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry, int xerr); int ovl_set_impure(struct dentry *dentry, struct dentry *upperdentry); void ovl_set_flag(unsigned long flag, struct inode *inode); +void ovl_clear_flag(unsigned long flag, struct inode *inode); bool ovl_test_flag(unsigned long flag, struct inode *inode); bool ovl_inuse_trylock(struct dentry *dentry); void ovl_inuse_unlock(struct dentry *dentry); @@ -254,6 +257,7 @@ extern const struct file_operations ovl_dir_operations; int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list); void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list); void ovl_cache_free(struct list_head *list); +void ovl_dir_cache_free(struct inode *inode); int ovl_check_d_type_supported(struct path *realpath); void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt, struct dentry *dentry, int level); @@ -270,9 +274,9 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr); int ovl_getattr(const struct path *path, struct kstat *stat, u32 request_mask, unsigned int flags); int ovl_permission(struct inode *inode, int mask); -int ovl_xattr_set(struct dentry *dentry, const char *name, const void *value, - size_t size, int flags); -int ovl_xattr_get(struct dentry *dentry, const char *name, +int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name, + const void *value, size_t size, int flags); +int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name, void *value, size_t size); ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); struct posix_acl *ovl_get_acl(struct inode *inode, int type); diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 0298463..62e9b22 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -15,11 +15,13 @@ #include <linux/rbtree.h> #include <linux/security.h> #include <linux/cred.h> +#include <linux/ratelimit.h> #include "overlayfs.h" struct ovl_cache_entry { unsigned int len; unsigned int type; + u64 real_ino; u64 ino; struct list_head l_node; struct rb_node node; @@ -32,18 +34,20 @@ struct ovl_dir_cache { long refcount; u64 version; struct list_head entries; + struct rb_root root; }; struct ovl_readdir_data { struct dir_context ctx; struct dentry *dentry; bool is_lowest; - struct rb_root root; + struct rb_root *root; struct list_head *list; struct list_head middle; struct ovl_cache_entry *first_maybe_whiteout; int count; int err; + bool is_upper; bool d_type_supported; }; @@ -58,7 +62,33 @@ struct ovl_dir_file { static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n) { - return container_of(n, struct ovl_cache_entry, node); + return rb_entry(n, struct ovl_cache_entry, node); +} + +static bool ovl_cache_entry_find_link(const char *name, int len, + struct rb_node ***link, + struct rb_node **parent) +{ + bool found = false; + struct rb_node **newp = *link; + + while (!found && *newp) { + int cmp; + struct ovl_cache_entry *tmp; + + *parent = *newp; + tmp = ovl_cache_entry_from_node(*newp); + cmp = strncmp(name, tmp->name, len); + if (cmp > 0) + newp = &tmp->node.rb_right; + else if (cmp < 0 || len < tmp->len) + newp = &tmp->node.rb_left; + else + found = true; + } + *link = newp; + + return found; } static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root, @@ -82,6 +112,32 @@ static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root, return NULL; } +static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd, + struct ovl_cache_entry *p) +{ + /* Don't care if not doing ovl_iter() */ + if (!rdd->dentry) + return false; + + /* Always recalc d_ino for parent */ + if (strcmp(p->name, "..") == 0) + return true; + + /* If this is lower, then native d_ino will do */ + if (!rdd->is_upper) + return false; + + /* + * Recalc d_ino for '.' and for all entries if dir is impure (contains + * copied up entries) + */ + if ((p->name[0] == '.' && p->len == 1) || + ovl_test_flag(OVL_IMPURE, d_inode(rdd->dentry))) + return true; + + return false; +} + static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, const char *name, int len, u64 ino, unsigned int d_type) @@ -97,7 +153,11 @@ static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd, p->name[len] = '\0'; p->len = len; p->type = d_type; + p->real_ino = ino; p->ino = ino; + /* Defer setting d_ino for upper entry to ovl_iterate() */ + if (ovl_calc_d_ino(rdd, p)) + p->ino = 0; p->is_whiteout = false; if (d_type == DT_CHR) { @@ -111,32 +171,22 @@ static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd, const char *name, int len, u64 ino, unsigned int d_type) { - struct rb_node **newp = &rdd->root.rb_node; + struct rb_node **newp = &rdd->root->rb_node; struct rb_node *parent = NULL; struct ovl_cache_entry *p; - while (*newp) { - int cmp; - struct ovl_cache_entry *tmp; - - parent = *newp; - tmp = ovl_cache_entry_from_node(*newp); - cmp = strncmp(name, tmp->name, len); - if (cmp > 0) - newp = &tmp->node.rb_right; - else if (cmp < 0 || len < tmp->len) - newp = &tmp->node.rb_left; - else - return 0; - } + if (ovl_cache_entry_find_link(name, len, &newp, &parent)) + return 0; p = ovl_cache_entry_new(rdd, name, len, ino, d_type); - if (p == NULL) + if (p == NULL) { + rdd->err = -ENOMEM; return -ENOMEM; + } list_add_tail(&p->l_node, rdd->list); rb_link_node(&p->node, parent, newp); - rb_insert_color(&p->node, &rdd->root); + rb_insert_color(&p->node, rdd->root); return 0; } @@ -147,7 +197,7 @@ static int ovl_fill_lowest(struct ovl_readdir_data *rdd, { struct ovl_cache_entry *p; - p = ovl_cache_entry_find(&rdd->root, name, namelen); + p = ovl_cache_entry_find(rdd->root, name, namelen); if (p) { list_move_tail(&p->l_node, &rdd->middle); } else { @@ -172,6 +222,16 @@ void ovl_cache_free(struct list_head *list) INIT_LIST_HEAD(list); } +void ovl_dir_cache_free(struct inode *inode) +{ + struct ovl_dir_cache *cache = ovl_dir_cache(inode); + + if (cache) { + ovl_cache_free(&cache->entries); + kfree(cache); + } +} + static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry) { struct ovl_dir_cache *cache = od->cache; @@ -179,8 +239,8 @@ static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry) WARN_ON(cache->refcount <= 0); cache->refcount--; if (!cache->refcount) { - if (ovl_dir_cache(dentry) == cache) - ovl_set_dir_cache(dentry, NULL); + if (ovl_dir_cache(d_inode(dentry)) == cache) + ovl_set_dir_cache(d_inode(dentry), NULL); ovl_cache_free(&cache->entries); kfree(cache); @@ -273,7 +333,8 @@ static void ovl_dir_reset(struct file *file) od->is_real = false; } -static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list) +static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list, + struct rb_root *root) { int err; struct path realpath; @@ -281,13 +342,14 @@ static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list) .ctx.actor = ovl_fill_merge, .dentry = dentry, .list = list, - .root = RB_ROOT, + .root = root, .is_lowest = false, }; int idx, next; for (idx = 0; idx != -1; idx = next) { next = ovl_path_next(idx, dentry, &realpath); + rdd.is_upper = ovl_dentry_upper(dentry) == realpath.dentry; if (next != -1) { err = ovl_dir_read(&realpath, &rdd); @@ -326,12 +388,13 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) int res; struct ovl_dir_cache *cache; - cache = ovl_dir_cache(dentry); + cache = ovl_dir_cache(d_inode(dentry)); if (cache && ovl_dentry_version_get(dentry) == cache->version) { + WARN_ON(!cache->refcount); cache->refcount++; return cache; } - ovl_set_dir_cache(dentry, NULL); + ovl_set_dir_cache(d_inode(dentry), NULL); cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL); if (!cache) @@ -339,8 +402,9 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) cache->refcount = 1; INIT_LIST_HEAD(&cache->entries); + cache->root = RB_ROOT; - res = ovl_dir_read_merged(dentry, &cache->entries); + res = ovl_dir_read_merged(dentry, &cache->entries, &cache->root); if (res) { ovl_cache_free(&cache->entries); kfree(cache); @@ -348,22 +412,266 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry) } cache->version = ovl_dentry_version_get(dentry); - ovl_set_dir_cache(dentry, cache); + ovl_set_dir_cache(d_inode(dentry), cache); return cache; } +/* + * Set d_ino for upper entries. Non-upper entries should always report + * the uppermost real inode ino and should not call this function. + * + * When not all layer are on same fs, report real ino also for upper. + * + * When all layers are on the same fs, and upper has a reference to + * copy up origin, call vfs_getattr() on the overlay entry to make + * sure that d_ino will be consistent with st_ino from stat(2). + */ +static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p) + +{ + struct dentry *dir = path->dentry; + struct dentry *this = NULL; + enum ovl_path_type type; + u64 ino = p->real_ino; + int err = 0; + + if (!ovl_same_sb(dir->d_sb)) + goto out; + + if (p->name[0] == '.') { + if (p->len == 1) { + this = dget(dir); + goto get; + } + if (p->len == 2 && p->name[1] == '.') { + /* we shall not be moved */ + this = dget(dir->d_parent); + goto get; + } + } + this = lookup_one_len(p->name, dir, p->len); + if (IS_ERR_OR_NULL(this) || !this->d_inode) { + if (IS_ERR(this)) { + err = PTR_ERR(this); + this = NULL; + goto fail; + } + goto out; + } + +get: + type = ovl_path_type(this); + if (OVL_TYPE_ORIGIN(type)) { + struct kstat stat; + struct path statpath = *path; + + statpath.dentry = this; + err = vfs_getattr(&statpath, &stat, STATX_INO, 0); + if (err) + goto fail; + + WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev); + ino = stat.ino; + } + +out: + p->ino = ino; + dput(this); + return err; + +fail: + pr_warn_ratelimited("overlay: failed to look up (%s) for ino (%i)\n", + p->name, err); + goto out; +} + +static int ovl_fill_plain(struct dir_context *ctx, const char *name, + int namelen, loff_t offset, u64 ino, + unsigned int d_type) +{ + struct ovl_cache_entry *p; + struct ovl_readdir_data *rdd = + container_of(ctx, struct ovl_readdir_data, ctx); + + rdd->count++; + p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type); + if (p == NULL) { + rdd->err = -ENOMEM; + return -ENOMEM; + } + list_add_tail(&p->l_node, rdd->list); + + return 0; +} + +static int ovl_dir_read_impure(struct path *path, struct list_head *list, + struct rb_root *root) +{ + int err; + struct path realpath; + struct ovl_cache_entry *p, *n; + struct ovl_readdir_data rdd = { + .ctx.actor = ovl_fill_plain, + .list = list, + .root = root, + }; + + INIT_LIST_HEAD(list); + *root = RB_ROOT; + ovl_path_upper(path->dentry, &realpath); + + err = ovl_dir_read(&realpath, &rdd); + if (err) + return err; + + list_for_each_entry_safe(p, n, list, l_node) { + if (strcmp(p->name, ".") != 0 && + strcmp(p->name, "..") != 0) { + err = ovl_cache_update_ino(path, p); + if (err) + return err; + } + if (p->ino == p->real_ino) { + list_del(&p->l_node); + kfree(p); + } else { + struct rb_node **newp = &root->rb_node; + struct rb_node *parent = NULL; + + if (WARN_ON(ovl_cache_entry_find_link(p->name, p->len, + &newp, &parent))) + return -EIO; + + rb_link_node(&p->node, parent, newp); + rb_insert_color(&p->node, root); + } + } + return 0; +} + +static struct ovl_dir_cache *ovl_cache_get_impure(struct path *path) +{ + int res; + struct dentry *dentry = path->dentry; + struct ovl_dir_cache *cache; + + cache = ovl_dir_cache(d_inode(dentry)); + if (cache && ovl_dentry_version_get(dentry) == cache->version) + return cache; + + /* Impure cache is not refcounted, free it here */ + ovl_dir_cache_free(d_inode(dentry)); + ovl_set_dir_cache(d_inode(dentry), NULL); + + cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL); + if (!cache) + return ERR_PTR(-ENOMEM); + + res = ovl_dir_read_impure(path, &cache->entries, &cache->root); + if (res) { + ovl_cache_free(&cache->entries); + kfree(cache); + return ERR_PTR(res); + } + if (list_empty(&cache->entries)) { + /* Good oportunity to get rid of an unnecessary "impure" flag */ + ovl_do_removexattr(ovl_dentry_upper(dentry), OVL_XATTR_IMPURE); + ovl_clear_flag(OVL_IMPURE, d_inode(dentry)); + kfree(cache); + return NULL; + } + + cache->version = ovl_dentry_version_get(dentry); + ovl_set_dir_cache(d_inode(dentry), cache); + + return cache; +} + +struct ovl_readdir_translate { + struct dir_context *orig_ctx; + struct ovl_dir_cache *cache; + struct dir_context ctx; + u64 parent_ino; +}; + +static int ovl_fill_real(struct dir_context *ctx, const char *name, + int namelen, loff_t offset, u64 ino, + unsigned int d_type) +{ + struct ovl_readdir_translate *rdt = + container_of(ctx, struct ovl_readdir_translate, ctx); + struct dir_context *orig_ctx = rdt->orig_ctx; + + if (rdt->parent_ino && strcmp(name, "..") == 0) + ino = rdt->parent_ino; + else if (rdt->cache) { + struct ovl_cache_entry *p; + + p = ovl_cache_entry_find(&rdt->cache->root, name, namelen); + if (p) + ino = p->ino; + } + + return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type); +} + +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_readdir_translate rdt = { + .ctx.actor = ovl_fill_real, + .orig_ctx = ctx, + }; + + if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) { + struct kstat stat; + struct path statpath = file->f_path; + + statpath.dentry = dir->d_parent; + err = vfs_getattr(&statpath, &stat, STATX_INO, 0); + if (err) + return err; + + WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev); + rdt.parent_ino = stat.ino; + } + + if (ovl_test_flag(OVL_IMPURE, d_inode(dir))) { + rdt.cache = ovl_cache_get_impure(&file->f_path); + if (IS_ERR(rdt.cache)) + return PTR_ERR(rdt.cache); + } + + return iterate_dir(od->realfile, &rdt.ctx); +} + + static int ovl_iterate(struct file *file, struct dir_context *ctx) { struct ovl_dir_file *od = file->private_data; struct dentry *dentry = file->f_path.dentry; struct ovl_cache_entry *p; + int err; if (!ctx->pos) ovl_dir_reset(file); - if (od->is_real) + if (od->is_real) { + /* + * If parent is merge, then need to adjust d_ino for '..', if + * 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)))) { + return ovl_iterate_real(file, ctx); + } return iterate_dir(od->realfile, ctx); + } if (!od->cache) { struct ovl_dir_cache *cache; @@ -378,9 +686,15 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx) while (od->cursor != &od->cache->entries) { p = list_entry(od->cursor, struct ovl_cache_entry, l_node); - if (!p->is_whiteout) + if (!p->is_whiteout) { + if (!p->ino) { + err = ovl_cache_update_ino(&file->f_path, p); + if (err) + return err; + } if (!dir_emit(ctx, p->name, p->len, p->ino, p->type)) break; + } od->cursor = p->l_node.next; ctx->pos++; } @@ -446,14 +760,14 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end, ovl_path_upper(dentry, &upperpath); realfile = ovl_path_open(&upperpath, O_RDONLY); - smp_mb__before_spinlock(); + inode_lock(inode); if (!od->upperfile) { if (IS_ERR(realfile)) { inode_unlock(inode); return PTR_ERR(realfile); } - od->upperfile = realfile; + smp_store_release(&od->upperfile, realfile); } else { /* somebody has beaten us to it */ if (!IS_ERR(realfile)) @@ -522,8 +836,9 @@ int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list) { int err; struct ovl_cache_entry *p; + struct rb_root root = RB_ROOT; - err = ovl_dir_read_merged(dentry, list); + err = ovl_dir_read_merged(dentry, list, &root); if (err) return err; @@ -612,12 +927,13 @@ static void ovl_workdir_cleanup_recurse(struct path *path, int level) int err; struct inode *dir = path->dentry->d_inode; LIST_HEAD(list); + struct rb_root root = RB_ROOT; struct ovl_cache_entry *p; struct ovl_readdir_data rdd = { .ctx.actor = ovl_fill_merge, .dentry = NULL, .list = &list, - .root = RB_ROOT, + .root = &root, .is_lowest = false, }; @@ -675,12 +991,13 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, struct inode *dir = dentry->d_inode; struct path path = { .mnt = mnt, .dentry = dentry }; LIST_HEAD(list); + struct rb_root root = RB_ROOT; struct ovl_cache_entry *p; struct ovl_readdir_data rdd = { .ctx.actor = ovl_fill_merge, .dentry = NULL, .list = &list, - .root = RB_ROOT, + .root = &root, .is_lowest = false, }; @@ -703,7 +1020,10 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt, err = PTR_ERR(index); break; } - if (ovl_verify_index(index, lowerstack, numlower)) { + err = ovl_verify_index(index, lowerstack, numlower); + if (err) { + if (err == -EROFS) + break; err = ovl_cleanup(dir, index); if (err) break; diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 22ee2a9..fd5ea4f 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -70,20 +70,20 @@ static int ovl_check_append_only(struct inode *inode, int flag) static struct dentry *ovl_d_real(struct dentry *dentry, const struct inode *inode, - unsigned int open_flags) + unsigned int open_flags, unsigned int flags) { struct dentry *real; int err; + if (flags & D_REAL_UPPER) + return ovl_dentry_upper(dentry); + if (!d_is_reg(dentry)) { if (!inode || inode == d_inode(dentry)) return dentry; goto bug; } - if (d_is_negative(dentry)) - return dentry; - if (open_flags) { err = ovl_open_maybe_copy_up(dentry, open_flags); if (err) @@ -105,7 +105,7 @@ static struct dentry *ovl_d_real(struct dentry *dentry, goto bug; /* Handle recursion */ - real = d_real(real, inode, open_flags); + real = d_real(real, inode, open_flags, 0); if (!inode || inode == d_inode(real)) return real; @@ -198,6 +198,7 @@ static void ovl_destroy_inode(struct inode *inode) dput(oi->__upperdentry); kfree(oi->redirect); + ovl_dir_cache_free(inode); mutex_destroy(&oi->lock); call_rcu(&inode->i_rcu, ovl_i_callback); @@ -692,7 +693,7 @@ ovl_posix_acl_xattr_get(const struct xattr_handler *handler, struct dentry *dentry, struct inode *inode, const char *name, void *buffer, size_t size) { - return ovl_xattr_get(dentry, handler->name, buffer, size); + return ovl_xattr_get(dentry, inode, handler->name, buffer, size); } static int __maybe_unused @@ -742,7 +743,7 @@ ovl_posix_acl_xattr_set(const struct xattr_handler *handler, return err; } - err = ovl_xattr_set(dentry, handler->name, value, size, flags); + err = ovl_xattr_set(dentry, inode, handler->name, value, size, flags); if (!err) ovl_copyattr(ovl_inode_real(inode), inode); @@ -772,7 +773,7 @@ static int ovl_other_xattr_get(const struct xattr_handler *handler, struct dentry *dentry, struct inode *inode, const char *name, void *buffer, size_t size) { - return ovl_xattr_get(dentry, name, buffer, size); + return ovl_xattr_get(dentry, inode, name, buffer, size); } static int ovl_other_xattr_set(const struct xattr_handler *handler, @@ -780,7 +781,7 @@ static int ovl_other_xattr_set(const struct xattr_handler *handler, const char *name, const void *value, size_t size, int flags) { - return ovl_xattr_set(dentry, name, value, size, flags); + return ovl_xattr_set(dentry, inode, name, value, size, flags); } static const struct xattr_handler __maybe_unused @@ -1058,10 +1059,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) ufs->indexdir = ovl_workdir_create(sb, ufs, workpath.dentry, OVL_INDEXDIR_NAME, true); - err = PTR_ERR(ufs->indexdir); - if (IS_ERR(ufs->indexdir)) - goto out_put_lower_mnt; - if (ufs->indexdir) { /* Verify upper root is index dir origin */ err = ovl_verify_origin(ufs->indexdir, ufs->upper_mnt, @@ -1090,6 +1087,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent) else sb->s_d_op = &ovl_dentry_operations; + err = -ENOMEM; ufs->creator_cred = cred = prepare_creds(); if (!cred) goto out_put_indexdir; diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c index c492ba7..1177945 100644 --- a/fs/overlayfs/util.c +++ b/fs/overlayfs/util.c @@ -157,9 +157,14 @@ struct dentry *ovl_dentry_real(struct dentry *dentry) return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry); } +struct dentry *ovl_i_dentry_upper(struct inode *inode) +{ + return ovl_upperdentry_dereference(OVL_I(inode)); +} + struct inode *ovl_inode_upper(struct inode *inode) { - struct dentry *upperdentry = ovl_upperdentry_dereference(OVL_I(inode)); + struct dentry *upperdentry = ovl_i_dentry_upper(inode); return upperdentry ? d_inode(upperdentry) : NULL; } @@ -175,14 +180,14 @@ struct inode *ovl_inode_real(struct inode *inode) } -struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry) +struct ovl_dir_cache *ovl_dir_cache(struct inode *inode) { - return OVL_I(d_inode(dentry))->cache; + return OVL_I(inode)->cache; } -void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache) +void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache) { - OVL_I(d_inode(dentry))->cache = cache; + OVL_I(inode)->cache = cache; } bool ovl_dentry_is_opaque(struct dentry *dentry) @@ -270,12 +275,19 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry) } } -void ovl_dentry_version_inc(struct dentry *dentry) +void ovl_dentry_version_inc(struct dentry *dentry, bool impurity) { struct inode *inode = d_inode(dentry); WARN_ON(!inode_is_locked(inode)); - OVL_I(inode)->version++; + /* + * Version is used by readdir code to keep cache consistent. For merge + * dirs all changes need to be noted. For non-merge dirs, cache only + * contains impure (ones which have been copied up and have origins) + * entries, so only need to note changes to impure entries. + */ + if (OVL_TYPE_MERGE(ovl_path_type(dentry)) || impurity) + OVL_I(inode)->version++; } u64 ovl_dentry_version_get(struct dentry *dentry) @@ -377,6 +389,11 @@ void ovl_set_flag(unsigned long flag, struct inode *inode) set_bit(flag, &OVL_I(inode)->flags); } +void ovl_clear_flag(unsigned long flag, struct inode *inode) +{ + clear_bit(flag, &OVL_I(inode)->flags); +} + bool ovl_test_flag(unsigned long flag, struct inode *inode) { return test_bit(flag, &OVL_I(inode)->flags); |
