diff options
Diffstat (limited to 'fs/overlayfs/dir.c')
-rw-r--r-- | fs/overlayfs/dir.c | 199 |
1 files changed, 93 insertions, 106 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index 3309b1912241..839709c7803a 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -63,8 +63,7 @@ struct dentry *ovl_lookup_temp(struct dentry *workdir) } /* caller holds i_mutex on workdir */ -static struct dentry *ovl_whiteout(struct dentry *workdir, - struct dentry *dentry) +static struct dentry *ovl_whiteout(struct dentry *workdir) { int err; struct dentry *whiteout; @@ -83,6 +82,38 @@ static struct dentry *ovl_whiteout(struct dentry *workdir, return whiteout; } +/* Caller must hold i_mutex on both workdir and dir */ +int ovl_cleanup_and_whiteout(struct dentry *workdir, struct inode *dir, + struct dentry *dentry) +{ + struct inode *wdir = workdir->d_inode; + struct dentry *whiteout; + int err; + int flags = 0; + + whiteout = ovl_whiteout(workdir); + err = PTR_ERR(whiteout); + if (IS_ERR(whiteout)) + return err; + + if (d_is_dir(dentry)) + flags = RENAME_EXCHANGE; + + err = ovl_do_rename(wdir, whiteout, dir, dentry, flags); + if (err) + goto kill_whiteout; + if (flags) + ovl_cleanup(wdir, dentry); + +out: + dput(whiteout); + return err; + +kill_whiteout: + ovl_cleanup(wdir, whiteout); + goto out; +} + int ovl_create_real(struct inode *dir, struct dentry *newdentry, struct cattr *attr, struct dentry *hardlink, bool debug) { @@ -216,26 +247,6 @@ out_unlock: return err; } -static int ovl_lock_rename_workdir(struct dentry *workdir, - struct dentry *upperdir) -{ - /* Workdir should not be the same as upperdir */ - if (workdir == upperdir) - goto err; - - /* Workdir should not be subdir of upperdir and vice versa */ - if (lock_rename(workdir, upperdir) != NULL) - goto err_unlock; - - return 0; - -err_unlock: - unlock_rename(workdir, upperdir); -err: - pr_err("overlayfs: failed to lock workdir+upperdir\n"); - return -EIO; -} - static struct dentry *ovl_clear_empty(struct dentry *dentry, struct list_head *list) { @@ -316,38 +327,6 @@ out: return ERR_PTR(err); } -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); - if (err) { - ret = ERR_PTR(err); - goto out_free; - } - - /* - * 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. - * - * 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)) - ret = ovl_clear_empty(dentry, &list); - -out_free: - ovl_cache_free(&list); - - return ret; -} - static int ovl_set_upper_acl(struct dentry *upperdentry, const char *name, const struct posix_acl *acl) { @@ -639,23 +618,20 @@ static bool ovl_matches_upper(struct dentry *dentry, struct dentry *upper) return d_inode(ovl_dentry_upper(dentry)) == d_inode(upper); } -static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir) +static int ovl_remove_and_whiteout(struct dentry *dentry, + struct list_head *list) { struct dentry *workdir = ovl_workdir(dentry); - struct inode *wdir = workdir->d_inode; struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); - struct inode *udir = upperdir->d_inode; - struct dentry *whiteout; struct dentry *upper; struct dentry *opaquedir = NULL; int err; - int flags = 0; if (WARN_ON(!workdir)) return -EROFS; - if (is_dir) { - opaquedir = ovl_check_empty_and_clear(dentry); + if (!list_empty(list)) { + opaquedir = ovl_clear_empty(dentry, list); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) goto out; @@ -678,24 +654,13 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir) goto out_dput_upper; } - whiteout = ovl_whiteout(workdir, dentry); - err = PTR_ERR(whiteout); - if (IS_ERR(whiteout)) - goto out_dput_upper; - - if (d_is_dir(upper)) - flags = RENAME_EXCHANGE; - - err = ovl_do_rename(wdir, whiteout, udir, upper, flags); + err = ovl_cleanup_and_whiteout(workdir, d_inode(upperdir), upper); if (err) - goto kill_whiteout; - if (flags) - ovl_cleanup(wdir, upper); + goto out_d_drop; ovl_dentry_version_inc(dentry->d_parent, true); out_d_drop: d_drop(dentry); - dput(whiteout); out_dput_upper: dput(upper); out_unlock: @@ -704,13 +669,10 @@ out_dput: dput(opaquedir); out: return err; - -kill_whiteout: - ovl_cleanup(wdir, whiteout); - goto out_d_drop; } -static int ovl_remove_upper(struct dentry *dentry, bool is_dir) +static int ovl_remove_upper(struct dentry *dentry, bool is_dir, + struct list_head *list) { struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); struct inode *dir = upperdir->d_inode; @@ -718,9 +680,8 @@ 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)) { - opaquedir = ovl_check_empty_and_clear(dentry); + if (!list_empty(list)) { + opaquedir = ovl_clear_empty(dentry, list); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) goto out; @@ -761,11 +722,26 @@ out: return err; } +static bool ovl_pure_upper(struct dentry *dentry) +{ + return !ovl_dentry_lower(dentry) && + !ovl_test_flag(OVL_WHITEOUTS, d_inode(dentry)); +} + static int ovl_do_remove(struct dentry *dentry, bool is_dir) { int err; bool locked = false; const struct cred *old_cred; + bool lower_positive = ovl_lower_positive(dentry); + LIST_HEAD(list); + + /* No need to clean pure upper removed by vfs_rmdir() */ + if (is_dir && (lower_positive || !ovl_pure_upper(dentry))) { + err = ovl_check_empty_dir(dentry, &list); + if (err) + goto out; + } err = ovl_want_write(dentry); if (err) @@ -780,10 +756,10 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir) goto out_drop_write; old_cred = ovl_override_creds(dentry->d_sb); - if (!ovl_lower_positive(dentry)) - err = ovl_remove_upper(dentry, is_dir); + if (!lower_positive) + err = ovl_remove_upper(dentry, is_dir, &list); else - err = ovl_remove_and_whiteout(dentry, is_dir); + err = ovl_remove_and_whiteout(dentry, &list); revert_creds(old_cred); if (!err) { if (is_dir) @@ -795,6 +771,7 @@ static int ovl_do_remove(struct dentry *dentry, bool is_dir) out_drop_write: ovl_drop_write(dentry); out: + ovl_cache_free(&list); return err; } @@ -902,7 +879,8 @@ static int ovl_set_redirect(struct dentry *dentry, bool samedir) spin_unlock(&dentry->d_lock); } else { kfree(redirect); - pr_warn_ratelimited("overlay: failed to set redirect (%i)\n", err); + pr_warn_ratelimited("overlayfs: failed to set redirect (%i)\n", + err); /* Fall back to userspace copy-up */ err = -EXDEV; } @@ -929,6 +907,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, bool samedir = olddir == newdir; struct dentry *opaquedir = NULL; const struct cred *old_cred = NULL; + LIST_HEAD(list); err = -EINVAL; if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) @@ -943,6 +922,27 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, if (!overwrite && !ovl_can_move(new)) goto out; + if (overwrite && new_is_dir && !ovl_pure_upper(new)) { + err = ovl_check_empty_dir(new, &list); + if (err) + goto out; + } + + if (overwrite) { + if (ovl_lower_positive(old)) { + if (!ovl_dentry_is_whiteout(new)) { + /* Whiteout source */ + flags |= RENAME_WHITEOUT; + } else { + /* Switch whiteouts */ + flags |= RENAME_EXCHANGE; + } + } else if (is_dir && ovl_dentry_is_whiteout(new)) { + flags |= RENAME_EXCHANGE; + cleanup_whiteout = true; + } + } + err = ovl_want_write(old); if (err) goto out; @@ -966,8 +966,8 @@ 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)) { - opaquedir = ovl_check_empty_and_clear(new); + if (!list_empty(&list)) { + opaquedir = ovl_clear_empty(new, &list); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) { opaquedir = NULL; @@ -975,21 +975,6 @@ static int ovl_rename(struct inode *olddir, struct dentry *old, } } - if (overwrite) { - if (ovl_lower_positive(old)) { - if (!ovl_dentry_is_whiteout(new)) { - /* Whiteout source */ - flags |= RENAME_WHITEOUT; - } else { - /* Switch whiteouts */ - flags |= RENAME_EXCHANGE; - } - } else if (is_dir && ovl_dentry_is_whiteout(new)) { - flags |= RENAME_EXCHANGE; - cleanup_whiteout = true; - } - } - old_upperdir = ovl_dentry_upper(old->d_parent); new_upperdir = ovl_dentry_upper(new->d_parent); @@ -1089,9 +1074,10 @@ 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); @@ -1106,6 +1092,7 @@ out_drop_write: ovl_drop_write(old); out: dput(opaquedir); + ovl_cache_free(&list); return err; } |