diff options
Diffstat (limited to 'fs/overlayfs/copy_up.c')
| -rw-r--r-- | fs/overlayfs/copy_up.c | 671 |
1 files changed, 438 insertions, 233 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index b193d08a3dc3..758611ee4475 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -16,7 +16,6 @@ #include <linux/sched/signal.h> #include <linux/cred.h> #include <linux/namei.h> -#include <linux/fdtable.h> #include <linux/ratelimit.h> #include <linux/exportfs.h> #include "overlayfs.h" @@ -44,16 +43,44 @@ static bool ovl_must_copy_xattr(const char *name) !strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN); } -int ovl_copy_xattr(struct super_block *sb, struct dentry *old, - struct dentry *new) +static int ovl_copy_acl(struct ovl_fs *ofs, const struct path *path, + struct dentry *dentry, const char *acl_name) { + int err; + struct posix_acl *clone, *real_acl = NULL; + + real_acl = ovl_get_acl_path(path, acl_name, false); + if (!real_acl) + return 0; + + if (IS_ERR(real_acl)) { + err = PTR_ERR(real_acl); + if (err == -ENODATA || err == -EOPNOTSUPP) + return 0; + return err; + } + + clone = posix_acl_clone(real_acl, GFP_KERNEL); + posix_acl_release(real_acl); /* release original acl */ + if (!clone) + return -ENOMEM; + + err = ovl_do_set_acl(ofs, dentry, acl_name, clone); + + /* release cloned acl */ + posix_acl_release(clone); + return err; +} + +int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct dentry *new) +{ + struct dentry *old = oldpath->dentry; ssize_t list_size, size, value_size = 0; char *buf, *name, *value = NULL; int error = 0; size_t slen; - if (!(old->d_inode->i_opflags & IOP_XATTR) || - !(new->d_inode->i_opflags & IOP_XATTR)) + if (!old->d_inode->i_op->listxattr || !new->d_inode->i_op->listxattr) return 0; list_size = vfs_listxattr(old, NULL, 0); @@ -86,17 +113,26 @@ int ovl_copy_xattr(struct super_block *sb, struct dentry *old, if (ovl_is_private_xattr(sb, name)) continue; - error = security_inode_copy_up_xattr(name); - if (error < 0 && error != -EOPNOTSUPP) - break; - if (error == 1) { + error = security_inode_copy_up_xattr(old, name); + if (error == -ECANCELED) { error = 0; continue; /* Discard */ } + if (error < 0 && error != -EOPNOTSUPP) + break; + + if (is_posix_acl_xattr(name)) { + error = ovl_copy_acl(OVL_FS(sb), oldpath, new, name); + if (!error) + continue; + /* POSIX ACLs must be copied. */ + break; + } + retry: - size = vfs_getxattr(&init_user_ns, old, name, value, value_size); + size = ovl_do_getxattr(oldpath, name, value, value_size); if (size == -ERANGE) - size = vfs_getxattr(&init_user_ns, old, name, NULL, 0); + size = ovl_do_getxattr(oldpath, name, NULL, 0); if (size < 0) { error = size; @@ -117,7 +153,7 @@ retry: goto retry; } - error = vfs_setxattr(&init_user_ns, new, name, value, size, 0); + error = ovl_do_setxattr(OVL_FS(sb), new, name, value, size, 0); if (error) { if (error != -EOPNOTSUPP || ovl_must_copy_xattr(name)) break; @@ -132,11 +168,11 @@ out: return error; } -static int ovl_copy_fileattr(struct inode *inode, struct path *old, - struct path *new) +static int ovl_copy_fileattr(struct inode *inode, const struct path *old, + const struct path *new) { - struct fileattr oldfa = { .flags_valid = true }; - struct fileattr newfa = { .flags_valid = true }; + struct file_kattr oldfa = { .flags_valid = true }; + struct file_kattr newfa = { .flags_valid = true }; int err; err = ovl_real_fileattr_get(old, &oldfa); @@ -145,7 +181,7 @@ static int ovl_copy_fileattr(struct inode *inode, struct path *old, if (err == -ENOTTY || err == -EINVAL) return 0; pr_warn("failed to retrieve lower fileattr (%pd2, err=%i)\n", - old, err); + old->dentry, err); return err; } @@ -157,7 +193,9 @@ static int ovl_copy_fileattr(struct inode *inode, struct path *old, */ if (oldfa.flags & OVL_PROT_FS_FLAGS_MASK) { err = ovl_set_protattr(inode, new->dentry, &oldfa); - if (err) + if (err == -EPERM) + pr_warn_once("copying fileattr: no xattr on upper\n"); + else if (err) return err; } @@ -167,8 +205,16 @@ static int ovl_copy_fileattr(struct inode *inode, struct path *old, err = ovl_real_fileattr_get(new, &newfa); if (err) { + /* + * Returning an error if upper doesn't support fileattr will + * result in a regression, so revert to the old behavior. + */ + if (err == -ENOTTY || err == -EINVAL) { + pr_warn_once("copying fileattr: no support on upper\n"); + return 0; + } pr_warn("failed to retrieve upper fileattr (%pd2, err=%i)\n", - new, err); + new->dentry, err); return err; } @@ -183,11 +229,40 @@ static int ovl_copy_fileattr(struct inode *inode, struct path *old, return ovl_real_fileattr_set(new, &newfa); } -static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, - struct path *new, loff_t len) +static int ovl_verify_area(loff_t pos, loff_t pos2, loff_t len, loff_t totlen) +{ + loff_t tmp; + + if (pos != pos2) + return -EIO; + if (pos < 0 || len < 0 || totlen < 0) + return -EIO; + if (check_add_overflow(pos, len, &tmp)) + return -EIO; + return 0; +} + +static int ovl_sync_file(const struct path *path) { - struct file *old_file; struct file *new_file; + int err; + + new_file = ovl_path_open(path, O_LARGEFILE | O_RDONLY); + if (IS_ERR(new_file)) + return PTR_ERR(new_file); + + err = vfs_fsync(new_file, 0); + fput(new_file); + + return err; +} + +static int ovl_copy_up_file(struct ovl_fs *ofs, struct dentry *dentry, + struct file *new_file, loff_t len, + bool datasync) +{ + struct path datapath; + struct file *old_file; loff_t old_pos = 0; loff_t new_pos = 0; loff_t cloned; @@ -196,33 +271,34 @@ static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, bool skip_hole = false; int error = 0; - if (len == 0) - return 0; + ovl_path_lowerdata(dentry, &datapath); + if (WARN_ON_ONCE(datapath.dentry == NULL) || + WARN_ON_ONCE(len < 0)) + return -EIO; - old_file = ovl_path_open(old, O_LARGEFILE | O_RDONLY); + old_file = ovl_path_open(&datapath, O_LARGEFILE | O_RDONLY); if (IS_ERR(old_file)) return PTR_ERR(old_file); - new_file = ovl_path_open(new, O_LARGEFILE | O_WRONLY); - if (IS_ERR(new_file)) { - error = PTR_ERR(new_file); - goto out_fput; - } - /* Try to use clone_file_range to clone up within the same fs */ - cloned = do_clone_file_range(old_file, 0, new_file, 0, len, 0); + cloned = vfs_clone_file_range(old_file, 0, new_file, 0, len, 0); if (cloned == len) - goto out; + goto out_fput; + /* Couldn't clone, so now we try to copy the data */ + error = rw_verify_area(READ, old_file, &old_pos, len); + if (!error) + error = rw_verify_area(WRITE, new_file, &new_pos, len); + if (error) + goto out_fput; /* Check if lower fs supports seek operation */ - if (old_file->f_mode & FMODE_LSEEK && - old_file->f_op->llseek) + if (old_file->f_mode & FMODE_LSEEK) skip_hole = true; while (len) { size_t this_len = OVL_COPY_UP_CHUNK_SIZE; - long bytes; + ssize_t bytes; if (len < this_len) this_len = len; @@ -246,8 +322,12 @@ static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, * it may not recognize all kind of holes and sometimes * only skips partial of hole area. However, it will be * enough for most of the use cases. + * + * We do not hold upper sb_writers throughout the loop to avert + * lockdep warning with llseek of lower file in nested overlay: + * - upper sb_writers + * -- lower ovl_inode_lock (ovl_llseek) */ - if (skip_hole && data_pos < old_pos) { data_pos = vfs_llseek(old_file, old_pos, SEEK_DATA); if (data_pos > old_pos) { @@ -262,6 +342,10 @@ static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, } } + error = ovl_verify_area(old_pos, new_pos, this_len, len); + if (error) + break; + bytes = do_splice_direct(old_file, &old_pos, new_file, &new_pos, this_len, SPLICE_F_MOVE); @@ -273,38 +357,40 @@ static int ovl_copy_up_data(struct ovl_fs *ofs, struct path *old, len -= bytes; } -out: - if (!error && ovl_should_sync(ofs)) + /* call fsync once, either now or later along with metadata */ + if (!error && ovl_should_sync(ofs) && datasync) error = vfs_fsync(new_file, 0); - fput(new_file); out_fput: fput(old_file); return error; } -static int ovl_set_size(struct dentry *upperdentry, struct kstat *stat) +static int ovl_set_size(struct ovl_fs *ofs, + struct dentry *upperdentry, struct kstat *stat) { struct iattr attr = { .ia_valid = ATTR_SIZE, .ia_size = stat->size, }; - return notify_change(&init_user_ns, upperdentry, &attr, NULL); + return ovl_do_notify_change(ofs, upperdentry, &attr); } -static int ovl_set_timestamps(struct dentry *upperdentry, struct kstat *stat) +static int ovl_set_timestamps(struct ovl_fs *ofs, struct dentry *upperdentry, + struct kstat *stat) { struct iattr attr = { .ia_valid = - ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET, + ATTR_ATIME | ATTR_MTIME | ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_CTIME, .ia_atime = stat->atime, .ia_mtime = stat->mtime, }; - return notify_change(&init_user_ns, upperdentry, &attr, NULL); + return ovl_do_notify_change(ofs, upperdentry, &attr); } -int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) +int ovl_set_attr(struct ovl_fs *ofs, struct dentry *upperdentry, + struct kstat *stat) { int err = 0; @@ -313,29 +399,29 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat) .ia_valid = ATTR_MODE, .ia_mode = stat->mode, }; - err = notify_change(&init_user_ns, upperdentry, &attr, NULL); + err = ovl_do_notify_change(ofs, upperdentry, &attr); } if (!err) { struct iattr attr = { .ia_valid = ATTR_UID | ATTR_GID, - .ia_uid = stat->uid, - .ia_gid = stat->gid, + .ia_vfsuid = VFSUIDT_INIT(stat->uid), + .ia_vfsgid = VFSGIDT_INIT(stat->gid), }; - err = notify_change(&init_user_ns, upperdentry, &attr, NULL); + err = ovl_do_notify_change(ofs, upperdentry, &attr); } if (!err) - ovl_set_timestamps(upperdentry, stat); + ovl_set_timestamps(ofs, upperdentry, stat); return err; } -struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, +struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct inode *realinode, bool is_upper) { struct ovl_fh *fh; int fh_type, dwords; int buflen = MAX_HANDLE_SZ; - uuid_t *uuid = &real->d_sb->s_uuid; + uuid_t *uuid = &realinode->i_sb->s_uuid; int err; /* Make sure the real fid stays 32bit aligned */ @@ -352,13 +438,13 @@ struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, * the price or reconnecting the dentry. */ dwords = buflen >> 2; - fh_type = exportfs_encode_fh(real, (void *)fh->fb.fid, &dwords, 0); + fh_type = exportfs_encode_inode_fh(realinode, (void *)fh->fb.fid, + &dwords, NULL, 0); buflen = (dwords << 2); err = -EIO; - if (WARN_ON(fh_type < 0) || - WARN_ON(buflen > MAX_HANDLE_SZ) || - WARN_ON(fh_type == FILEID_INVALID)) + if (fh_type < 0 || fh_type == FILEID_INVALID || + WARN_ON(buflen > MAX_HANDLE_SZ)) goto out_err; fh->fb.version = OVL_FH_VERSION; @@ -374,7 +460,7 @@ struct ovl_fh *ovl_encode_real_fh(struct ovl_fs *ofs, struct dentry *real, if (is_upper) fh->fb.flags |= OVL_FH_FLAG_PATH_UPPER; fh->fb.len = sizeof(fh->fb) + buflen; - if (ofs->config.uuid) + if (ovl_origin_uuid(ofs)) fh->fb.uuid = *uuid; return fh; @@ -384,29 +470,29 @@ out_err: return ERR_PTR(err); } -int ovl_set_origin(struct ovl_fs *ofs, struct dentry *lower, - struct dentry *upper) +struct ovl_fh *ovl_get_origin_fh(struct ovl_fs *ofs, struct dentry *origin) { - const struct ovl_fh *fh = NULL; - int err; - /* * When lower layer doesn't support export operations store a 'null' fh, * so we can use the overlay.origin xattr to distignuish between a copy * up and a pure upper inode. */ - if (ovl_can_decode_fh(lower->d_sb)) { - fh = ovl_encode_real_fh(ofs, lower, false); - if (IS_ERR(fh)) - return PTR_ERR(fh); - } + if (!ovl_can_decode_fh(origin->d_sb)) + return NULL; + + return ovl_encode_real_fh(ofs, d_inode(origin), false); +} + +int ovl_set_origin_fh(struct ovl_fs *ofs, const struct ovl_fh *fh, + struct dentry *upper) +{ + int err; /* * Do not fail when upper doesn't support xattrs. */ err = ovl_check_setxattr(ofs, upper, OVL_XATTR_ORIGIN, fh->buf, fh ? fh->fb.len : 0, 0); - kfree(fh); /* Ignore -EPERM from setting "user.*" on symlink/special */ return err == -EPERM ? 0 : err; @@ -419,11 +505,11 @@ static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper, const struct ovl_fh *fh; int err; - fh = ovl_encode_real_fh(ofs, upper, true); + fh = ovl_encode_real_fh(ofs, d_inode(upper), true); if (IS_ERR(fh)) return PTR_ERR(fh); - err = ovl_do_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len); + err = ovl_setxattr(ofs, index, OVL_XATTR_UPPER, fh->buf, fh->fb.len); kfree(fh); return err; @@ -431,17 +517,14 @@ static int ovl_set_upper_fh(struct ovl_fs *ofs, struct dentry *upper, /* * Create and install index entry. - * - * Caller must hold i_mutex on indexdir. */ -static int ovl_create_index(struct dentry *dentry, struct dentry *origin, +static int ovl_create_index(struct dentry *dentry, const struct ovl_fh *fh, struct dentry *upper) { struct ovl_fs *ofs = OVL_FS(dentry->d_sb); struct dentry *indexdir = ovl_indexdir(dentry->d_sb); - struct inode *dir = d_inode(indexdir); - struct dentry *index = NULL; struct dentry *temp = NULL; + struct renamedata rd = {}; struct qstr name = { }; int err; @@ -460,11 +543,11 @@ static int ovl_create_index(struct dentry *dentry, struct dentry *origin, if (WARN_ON(ovl_test_flag(OVL_INDEX, d_inode(dentry)))) return -EIO; - err = ovl_get_index_name(ofs, origin, &name); + err = ovl_get_index_name_fh(fh, &name); if (err) return err; - temp = ovl_create_temp(indexdir, OVL_CATTR(S_IFDIR | 0)); + temp = ovl_create_temp(ofs, indexdir, OVL_CATTR(S_IFDIR | 0)); err = PTR_ERR(temp); if (IS_ERR(temp)) goto free_name; @@ -473,16 +556,18 @@ static int ovl_create_index(struct dentry *dentry, struct dentry *origin, if (err) goto out; - index = lookup_one_len(name.name, indexdir, name.len); - if (IS_ERR(index)) { - err = PTR_ERR(index); - } else { - err = ovl_do_rename(dir, temp, dir, index, 0); - dput(index); - } + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = indexdir; + rd.new_parent = indexdir; + err = start_renaming_dentry(&rd, 0, temp, &name); + if (err) + goto out; + + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); out: if (err) - ovl_cleanup(dir, temp); + ovl_cleanup(ofs, indexdir, temp); dput(temp); free_name: kfree(name.name); @@ -499,9 +584,12 @@ struct ovl_copy_up_ctx { struct dentry *destdir; struct qstr destname; struct dentry *workdir; + const struct ovl_fh *origin_fh; bool origin; bool indexed; bool metacopy; + bool metacopy_digest; + bool metadata_fsync; }; static int ovl_link_up(struct ovl_copy_up_ctx *c) @@ -509,70 +597,78 @@ static int ovl_link_up(struct ovl_copy_up_ctx *c) int err; struct dentry *upper; struct dentry *upperdir = ovl_dentry_upper(c->parent); + struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); struct inode *udir = d_inode(upperdir); + ovl_start_write(c->dentry); + /* Mark parent "impure" because it may now contain non-pure upper */ err = ovl_set_impure(c->parent, upperdir); if (err) - return err; + goto out; err = ovl_set_nlink_lower(c->dentry); if (err) - return err; + goto out; - inode_lock_nested(udir, I_MUTEX_PARENT); - upper = lookup_one_len(c->dentry->d_name.name, upperdir, - c->dentry->d_name.len); + upper = ovl_start_creating_upper(ofs, upperdir, + &QSTR_LEN(c->dentry->d_name.name, + c->dentry->d_name.len)); err = PTR_ERR(upper); if (!IS_ERR(upper)) { - err = ovl_do_link(ovl_dentry_upper(c->dentry), udir, upper); - dput(upper); + err = ovl_do_link(ofs, ovl_dentry_upper(c->dentry), udir, upper); if (!err) { /* Restore timestamps on parent (best effort) */ - ovl_set_timestamps(upperdir, &c->pstat); + ovl_set_timestamps(ofs, upperdir, &c->pstat); ovl_dentry_set_upper_alias(c->dentry); + ovl_dentry_update_reval(c->dentry, upper); } + end_creating(upper); } - inode_unlock(udir); if (err) - return err; + goto out; err = ovl_set_nlink_upper(c->dentry); +out: + ovl_end_write(c->dentry); return err; } -static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) +static int ovl_copy_up_data(struct ovl_copy_up_ctx *c, const struct path *temp) { struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); - struct inode *inode = d_inode(c->dentry); - struct path upperpath, datapath; + struct file *new_file; int err; - ovl_path_upper(c->dentry, &upperpath); - if (WARN_ON(upperpath.dentry != NULL)) - return -EIO; + if (!S_ISREG(c->stat.mode) || c->metacopy || !c->stat.size) + return 0; - upperpath.dentry = temp; + new_file = ovl_path_open(temp, O_LARGEFILE | O_WRONLY); + if (IS_ERR(new_file)) + return PTR_ERR(new_file); - /* - * Copy up data first and then xattrs. Writing data after - * xattrs will remove security.capability xattr automatically. - */ - if (S_ISREG(c->stat.mode) && !c->metacopy) { - ovl_path_lowerdata(c->dentry, &datapath); - err = ovl_copy_up_data(ofs, &datapath, &upperpath, - c->stat.size); - if (err) - return err; - } + err = ovl_copy_up_file(ofs, c->dentry, new_file, c->stat.size, + !c->metadata_fsync); + fput(new_file); + + return err; +} - err = ovl_copy_xattr(c->dentry->d_sb, c->lowerpath.dentry, temp); +static int ovl_copy_up_metadata(struct ovl_copy_up_ctx *c, struct dentry *temp) +{ + struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); + struct inode *inode = d_inode(c->dentry); + struct path upperpath = { .mnt = ovl_upper_mnt(ofs), .dentry = temp }; + int err; + + err = ovl_copy_xattr(c->dentry->d_sb, &c->lowerpath, temp); if (err) return err; - if (inode->i_flags & OVL_COPY_I_FLAGS_MASK) { + if (inode->i_flags & OVL_FATTR_I_FLAGS_MASK && + (S_ISREG(c->stat.mode) || S_ISDIR(c->stat.mode))) { /* * Copy the fileattr inode flags that are the source of already * copied i_flags @@ -590,66 +686,82 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp) * hard link. */ if (c->origin) { - err = ovl_set_origin(ofs, c->lowerpath.dentry, temp); + err = ovl_set_origin_fh(ofs, c->origin_fh, temp); if (err) return err; } if (c->metacopy) { - err = ovl_check_setxattr(ofs, temp, OVL_XATTR_METACOPY, - NULL, 0, -EOPNOTSUPP); + struct path lowerdatapath; + struct ovl_metacopy metacopy_data = OVL_METACOPY_INIT; + + ovl_path_lowerdata(c->dentry, &lowerdatapath); + if (WARN_ON_ONCE(lowerdatapath.dentry == NULL)) + return -EIO; + err = ovl_get_verity_digest(ofs, &lowerdatapath, &metacopy_data); + if (err) + return err; + + if (metacopy_data.digest_algo) + c->metacopy_digest = true; + + err = ovl_set_metacopy_xattr(ofs, temp, &metacopy_data); if (err) return err; } inode_lock(temp->d_inode); if (S_ISREG(c->stat.mode)) - err = ovl_set_size(temp, &c->stat); + err = ovl_set_size(ofs, temp, &c->stat); if (!err) - err = ovl_set_attr(temp, &c->stat); + err = ovl_set_attr(ofs, temp, &c->stat); inode_unlock(temp->d_inode); + /* fsync metadata before moving it into upper dir */ + if (!err && ovl_should_sync(ofs) && c->metadata_fsync) + err = ovl_sync_file(&upperpath); + return err; } -struct ovl_cu_creds { - const struct cred *old; - struct cred *new; -}; - -static int ovl_prep_cu_creds(struct dentry *dentry, struct ovl_cu_creds *cc) +static const struct cred *ovl_prepare_copy_up_creds(struct dentry *dentry) { + struct cred *copy_up_cred = NULL; int err; - cc->old = cc->new = NULL; - err = security_inode_copy_up(dentry, &cc->new); + err = security_inode_copy_up(dentry, ©_up_cred); if (err < 0) - return err; + return ERR_PTR(err); - if (cc->new) - cc->old = override_creds(cc->new); + if (!copy_up_cred) + return NULL; - return 0; + return override_creds(copy_up_cred); } -static void ovl_revert_cu_creds(struct ovl_cu_creds *cc) +static void ovl_revert_copy_up_creds(const struct cred *orig_cred) { - if (cc->new) { - revert_creds(cc->old); - put_cred(cc->new); - } + const struct cred *copy_up_cred; + + copy_up_cred = revert_creds(orig_cred); + put_cred(copy_up_cred); } +DEFINE_CLASS(copy_up_creds, const struct cred *, + if (!IS_ERR_OR_NULL(_T)) ovl_revert_copy_up_creds(_T), + ovl_prepare_copy_up_creds(dentry), struct dentry *dentry) + /* * Copyup using workdir to prepare temp file. Used when copying up directories, * special files or when upper fs doesn't support O_TMPFILE. */ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) { + struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); struct inode *inode; - struct inode *udir = d_inode(c->destdir), *wdir = d_inode(c->workdir); - struct dentry *temp, *upper; - struct ovl_cu_creds cc; + struct path path = { .mnt = ovl_upper_mnt(ofs) }; + struct renamedata rd = {}; + struct dentry *temp; int err; struct ovl_cattr cattr = { /* Can't properly set mode on creation because of the umask */ @@ -658,102 +770,145 @@ static int ovl_copy_up_workdir(struct ovl_copy_up_ctx *c) .link = c->link }; - /* workdir and destdir could be the same when copying up to indexdir */ - err = -EIO; - if (lock_rename(c->workdir, c->destdir) != NULL) - goto unlock; - - err = ovl_prep_cu_creds(c->dentry, &cc); - if (err) - goto unlock; + scoped_class(copy_up_creds, copy_up_creds, c->dentry) { + if (IS_ERR(copy_up_creds)) + return PTR_ERR(copy_up_creds); - temp = ovl_create_temp(c->workdir, &cattr); - ovl_revert_cu_creds(&cc); + ovl_start_write(c->dentry); + temp = ovl_create_temp(ofs, c->workdir, &cattr); + ovl_end_write(c->dentry); + } - err = PTR_ERR(temp); if (IS_ERR(temp)) - goto unlock; + return PTR_ERR(temp); - err = ovl_copy_up_inode(c, temp); + /* + * Copy up data first and then xattrs. Writing data after + * xattrs will remove security.capability xattr automatically. + */ + path.dentry = temp; + err = ovl_copy_up_data(c, &path); + ovl_start_write(c->dentry); if (err) - goto cleanup; + goto cleanup_unlocked; if (S_ISDIR(c->stat.mode) && c->indexed) { - err = ovl_create_index(c->dentry, c->lowerpath.dentry, temp); + err = ovl_create_index(c->dentry, c->origin_fh, temp); if (err) - goto cleanup; + goto cleanup_unlocked; } - upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); - err = PTR_ERR(upper); - if (IS_ERR(upper)) - goto cleanup; + /* + * We cannot hold lock_rename() throughout this helper, because of + * lock ordering with sb_writers, which shouldn't be held when calling + * ovl_copy_up_data(), so lock workdir and destdir and make sure that + * temp wasn't moved before copy up completion or cleanup. + */ + rd.mnt_idmap = ovl_upper_mnt_idmap(ofs); + rd.old_parent = c->workdir; + rd.new_parent = c->destdir; + rd.flags = 0; + err = start_renaming_dentry(&rd, 0, temp, + &QSTR_LEN(c->destname.name, c->destname.len)); + if (err) { + /* temp or workdir moved underneath us? map to -EIO */ + err = -EIO; + } + if (err) + goto cleanup_unlocked; + + err = ovl_copy_up_metadata(c, temp); + if (!err) + err = ovl_do_rename_rd(&rd); + end_renaming(&rd); - err = ovl_do_rename(wdir, temp, udir, upper, 0); - dput(upper); if (err) - goto cleanup; + goto cleanup_unlocked; - if (!c->metacopy) - ovl_set_upperdata(d_inode(c->dentry)); inode = d_inode(c->dentry); + if (c->metacopy_digest) + ovl_set_flag(OVL_HAS_DIGEST, inode); + else + ovl_clear_flag(OVL_HAS_DIGEST, inode); + ovl_clear_flag(OVL_VERIFIED_DIGEST, inode); + + if (!c->metacopy) + ovl_set_upperdata(inode); ovl_inode_update(inode, temp); if (S_ISDIR(inode->i_mode)) ovl_set_flag(OVL_WHITEOUTS, inode); -unlock: - unlock_rename(c->workdir, c->destdir); +out: + ovl_end_write(c->dentry); return err; -cleanup: - ovl_cleanup(wdir, temp); +cleanup_unlocked: + ovl_cleanup(ofs, c->workdir, temp); dput(temp); - goto unlock; + goto out; } /* Copyup using O_TMPFILE which does not require cross dir locking */ static int ovl_copy_up_tmpfile(struct ovl_copy_up_ctx *c) { + struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); struct inode *udir = d_inode(c->destdir); struct dentry *temp, *upper; - struct ovl_cu_creds cc; + struct file *tmpfile; int err; - err = ovl_prep_cu_creds(c->dentry, &cc); - if (err) - return err; + scoped_class(copy_up_creds, copy_up_creds, c->dentry) { + if (IS_ERR(copy_up_creds)) + return PTR_ERR(copy_up_creds); - temp = ovl_do_tmpfile(c->workdir, c->stat.mode); - ovl_revert_cu_creds(&cc); + ovl_start_write(c->dentry); + tmpfile = ovl_do_tmpfile(ofs, c->workdir, c->stat.mode); + ovl_end_write(c->dentry); + } - if (IS_ERR(temp)) - return PTR_ERR(temp); + if (IS_ERR(tmpfile)) + return PTR_ERR(tmpfile); - err = ovl_copy_up_inode(c, temp); - if (err) - goto out_dput; + temp = tmpfile->f_path.dentry; + if (!c->metacopy && c->stat.size) { + err = ovl_copy_up_file(ofs, c->dentry, tmpfile, c->stat.size, + !c->metadata_fsync); + if (err) + goto out_fput; + } - inode_lock_nested(udir, I_MUTEX_PARENT); + ovl_start_write(c->dentry); - upper = lookup_one_len(c->destname.name, c->destdir, c->destname.len); + err = ovl_copy_up_metadata(c, temp); + if (err) + goto out; + + upper = ovl_start_creating_upper(ofs, c->destdir, + &QSTR_LEN(c->destname.name, + c->destname.len)); err = PTR_ERR(upper); if (!IS_ERR(upper)) { - err = ovl_do_link(temp, udir, upper); - dput(upper); + err = ovl_do_link(ofs, temp, udir, upper); + end_creating(upper); } - inode_unlock(udir); if (err) - goto out_dput; + goto out; + + if (c->metacopy_digest) + ovl_set_flag(OVL_HAS_DIGEST, d_inode(c->dentry)); + else + ovl_clear_flag(OVL_HAS_DIGEST, d_inode(c->dentry)); + ovl_clear_flag(OVL_VERIFIED_DIGEST, d_inode(c->dentry)); if (!c->metacopy) ovl_set_upperdata(d_inode(c->dentry)); - ovl_inode_update(d_inode(c->dentry), temp); - - return 0; + ovl_inode_update(d_inode(c->dentry), dget(temp)); -out_dput: - dput(temp); +out: + ovl_end_write(c->dentry); +out_fput: + fput(tmpfile); return err; } @@ -770,6 +925,8 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) { int err; struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); + struct dentry *origin = c->lowerpath.dentry; + struct ovl_fh *fh = NULL; bool to_index = false; /* @@ -786,25 +943,42 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) to_index = true; } - if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) + if (S_ISDIR(c->stat.mode) || c->stat.nlink == 1 || to_index) { + fh = ovl_get_origin_fh(ofs, origin); + if (IS_ERR(fh)) + return PTR_ERR(fh); + + /* origin_fh may be NULL */ + c->origin_fh = fh; c->origin = true; + } if (to_index) { c->destdir = ovl_indexdir(c->dentry->d_sb); - err = ovl_get_index_name(ofs, c->lowerpath.dentry, &c->destname); + err = ovl_get_index_name(ofs, origin, &c->destname); if (err) - return err; + goto out_free_fh; } else if (WARN_ON(!c->parent)) { /* Disconnected dentry must be copied up to index dir */ - return -EIO; + err = -EIO; + goto out_free_fh; } else { /* + * c->dentry->d_name is stabilzed by ovl_copy_up_start(), + * because if we got here, it means that c->dentry has no upper + * alias and changing ->d_name means going through ovl_rename() + * that will call ovl_copy_up() on source and target dentry. + */ + c->destname = c->dentry->d_name; + /* * Mark parent "impure" because it may now contain non-pure * upper */ + ovl_start_write(c->dentry); err = ovl_set_impure(c->parent, c->destdir); + ovl_end_write(c->dentry); if (err) - return err; + goto out_free_fh; } /* Should we copyup with O_TMPFILE or with workdir? */ @@ -818,6 +992,7 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) if (c->indexed) ovl_set_flag(OVL_INDEX, d_inode(c->dentry)); + ovl_start_write(c->dentry); if (to_index) { /* Initialize nlink for copy up of disconnected dentry */ err = ovl_set_nlink_upper(c->dentry); @@ -826,22 +1001,26 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c) /* Restore timestamps on parent (best effort) */ inode_lock(udir); - ovl_set_timestamps(c->destdir, &c->pstat); + ovl_set_timestamps(ofs, c->destdir, &c->pstat); inode_unlock(udir); ovl_dentry_set_upper_alias(c->dentry); + ovl_dentry_update_reval(c->dentry, ovl_dentry_upper(c->dentry)); } + ovl_end_write(c->dentry); out: if (to_index) kfree(c->destname.name); +out_free_fh: + kfree(fh); return err; } static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, int flags) { - struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct ovl_fs *ofs = OVL_FS(dentry->d_sb); if (!ofs->config.metacopy) return false; @@ -852,15 +1031,28 @@ static bool ovl_need_meta_copy_up(struct dentry *dentry, umode_t mode, if (flags && ((OPEN_FMODE(flags) & FMODE_WRITE) || (flags & O_TRUNC))) return false; + /* Fall back to full copy if no fsverity on source data and we require verity */ + if (ofs->config.verity_mode == OVL_VERITY_REQUIRE) { + struct path lowerdata; + + ovl_path_lowerdata(dentry, &lowerdata); + + if (WARN_ON_ONCE(lowerdata.dentry == NULL) || + ovl_ensure_verity_loaded(&lowerdata) || + !fsverity_active(d_inode(lowerdata.dentry))) { + return false; + } + } + return true; } -static ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value) +static ssize_t ovl_getxattr_value(const struct path *path, char *name, char **value) { ssize_t res; char *buf; - res = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0); + res = ovl_do_getxattr(path, name, NULL, 0); if (res == -ENODATA || res == -EOPNOTSUPP) res = 0; @@ -869,7 +1061,7 @@ static ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value) if (!buf) return -ENOMEM; - res = vfs_getxattr(&init_user_ns, dentry, name, buf, res); + res = ovl_do_getxattr(path, name, buf, res); if (res < 0) kfree(buf); else @@ -882,7 +1074,7 @@ static ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value) static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) { struct ovl_fs *ofs = OVL_FS(c->dentry->d_sb); - struct path upperpath, datapath; + struct path upperpath; int err; char *capability = NULL; ssize_t cap_size; @@ -891,18 +1083,14 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) if (WARN_ON(upperpath.dentry == NULL)) return -EIO; - ovl_path_lowerdata(c->dentry, &datapath); - if (WARN_ON(datapath.dentry == NULL)) - return -EIO; - if (c->stat.size) { - err = cap_size = ovl_getxattr(upperpath.dentry, XATTR_NAME_CAPS, - &capability); + err = cap_size = ovl_getxattr_value(&upperpath, XATTR_NAME_CAPS, + &capability); if (cap_size < 0) goto out; } - err = ovl_copy_up_data(ofs, &datapath, &upperpath, c->stat.size); + err = ovl_copy_up_data(c, &upperpath); if (err) goto out_free; @@ -910,18 +1098,21 @@ static int ovl_copy_up_meta_inode_data(struct ovl_copy_up_ctx *c) * Writing to upper file will clear security.capability xattr. We * don't want that to happen for normal copy-up operation. */ + ovl_start_write(c->dentry); if (capability) { - err = vfs_setxattr(&init_user_ns, upperpath.dentry, - XATTR_NAME_CAPS, capability, cap_size, 0); - if (err) - goto out_free; + err = ovl_do_setxattr(ofs, upperpath.dentry, XATTR_NAME_CAPS, + capability, cap_size, 0); } - - - err = ovl_do_removexattr(ofs, upperpath.dentry, OVL_XATTR_METACOPY); + if (!err) { + err = ovl_removexattr(ofs, upperpath.dentry, + OVL_XATTR_METACOPY); + } + ovl_end_write(c->dentry); if (err) goto out_free; + ovl_clear_flag(OVL_HAS_DIGEST, d_inode(c->dentry)); + ovl_clear_flag(OVL_VERIFIED_DIGEST, d_inode(c->dentry)); ovl_set_upperdata(d_inode(c->dentry)); out_free: kfree(capability); @@ -950,12 +1141,26 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, if (err) return err; + if (!kuid_has_mapping(current_user_ns(), ctx.stat.uid) || + !kgid_has_mapping(current_user_ns(), ctx.stat.gid)) + return -EOVERFLOW; + + /* + * With metacopy disabled, we fsync after final metadata copyup, for + * both regular files and directories to get atomic copyup semantics + * on filesystems that do not use strict metadata ordering (e.g. ubifs). + * + * With metacopy enabled we want to avoid fsync on all meta copyup + * that will hurt performance of workloads such as chown -R, so we + * only fsync on data copyup as legacy behavior. + */ + ctx.metadata_fsync = !OVL_FS(dentry->d_sb)->config.metacopy && + (S_ISREG(ctx.stat.mode) || S_ISDIR(ctx.stat.mode)); ctx.metacopy = ovl_need_meta_copy_up(dentry, ctx.stat.mode, flags); if (parent) { ovl_path_upper(parent, &parentpath); ctx.destdir = parentpath.dentry; - ctx.destname = dentry->d_name; err = vfs_getattr(&parentpath, &ctx.pstat, STATX_ATIME | STATX_MTIME, @@ -996,7 +1201,6 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, static int ovl_copy_up_flags(struct dentry *dentry, int flags) { int err = 0; - const struct cred *old_cred; bool disconnected = (dentry->d_flags & DCACHE_DISCONNECTED); /* @@ -1007,7 +1211,15 @@ static int ovl_copy_up_flags(struct dentry *dentry, int flags) if (WARN_ON(disconnected && d_is_dir(dentry))) return -EIO; - old_cred = ovl_override_creds(dentry->d_sb); + /* + * We may not need lowerdata if we are only doing metacopy up, but it is + * not very important to optimize this case, so do lazy lowerdata lookup + * before any copy up, so we can do it before taking ovl_inode_lock(). + */ + err = ovl_verify_lowerdata(dentry); + if (err) + return err; + while (!err) { struct dentry *next; struct dentry *parent = NULL; @@ -1027,12 +1239,12 @@ static int ovl_copy_up_flags(struct dentry *dentry, int flags) next = parent; } - err = ovl_copy_up_one(parent, next, flags); + with_ovl_creds(dentry->d_sb) + err = ovl_copy_up_one(parent, next, flags); dput(parent); dput(next); } - revert_creds(old_cred); return err; } @@ -1054,17 +1266,10 @@ static bool ovl_open_need_copy_up(struct dentry *dentry, int flags) int ovl_maybe_copy_up(struct dentry *dentry, int flags) { - int err = 0; - - if (ovl_open_need_copy_up(dentry, flags)) { - err = ovl_want_write(dentry); - if (!err) { - err = ovl_copy_up_flags(dentry, flags); - ovl_drop_write(dentry); - } - } + if (!ovl_open_need_copy_up(dentry, flags)) + return 0; - return err; + return ovl_copy_up_flags(dentry, flags); } int ovl_copy_up_with_data(struct dentry *dentry) |
