cregit-Linux how code gets into the kernel

Release 4.10 fs/overlayfs/dir.c

Directory: fs/overlayfs
/*
 *
 * Copyright (C) 2011 Novell Inc.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/fs.h>
#include <linux/namei.h>
#include <linux/xattr.h>
#include <linux/security.h>
#include <linux/cred.h>
#include <linux/module.h>
#include <linux/posix_acl.h>
#include <linux/posix_acl_xattr.h>
#include <linux/atomic.h>
#include <linux/ratelimit.h>
#include "overlayfs.h"


static unsigned short ovl_redirect_max = 256;
module_param_named(redirect_max, ovl_redirect_max, ushort, 0644);
MODULE_PARM_DESC(ovl_redirect_max,
		 "Maximum length of absolute redirect xattr value");


void ovl_cleanup(struct inode *wdir, struct dentry *wdentry) { int err; dget(wdentry); if (d_is_dir(wdentry)) err = ovl_do_rmdir(wdir, wdentry); else err = ovl_do_unlink(wdir, wdentry); dput(wdentry); if (err) { pr_err("overlayfs: cleanup of '%pd2' failed (%i)\n", wdentry, err); } }

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david howellsdavid howells11.45%150.00%
Total69100.00%2100.00%


struct dentry *ovl_lookup_temp(struct dentry *workdir, struct dentry *dentry) { struct dentry *temp; char name[20]; static atomic_t temp_id = ATOMIC_INIT(0); /* counter is allowed to wrap, since temp dentries are ephemeral */ snprintf(name, sizeof(name), "#%x", atomic_inc_return(&temp_id)); temp = lookup_one_len(name, workdir, strlen(name)); if (!IS_ERR(temp) && temp->d_inode) { pr_err("overlayfs: workdir/%s already exists\n", name); dput(temp); temp = ERR_PTR(-EIO); } return temp; }

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richard weinbergerrichard weinberger1614.95%150.00%
Total107100.00%2100.00%

/* caller holds i_mutex on workdir */
static struct dentry *ovl_whiteout(struct dentry *workdir, struct dentry *dentry) { int err; struct dentry *whiteout; struct inode *wdir = workdir->d_inode; whiteout = ovl_lookup_temp(workdir, dentry); if (IS_ERR(whiteout)) return whiteout; err = ovl_do_whiteout(wdir, whiteout); if (err) { dput(whiteout); whiteout = ERR_PTR(err); } return whiteout; }

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int ovl_create_real(struct inode *dir, struct dentry *newdentry, struct cattr *attr, struct dentry *hardlink, bool debug) { int err; if (newdentry->d_inode) return -ESTALE; if (hardlink) { err = ovl_do_link(hardlink, dir, newdentry, debug); } else { switch (attr->mode & S_IFMT) { case S_IFREG: err = ovl_do_create(dir, newdentry, attr->mode, debug); break; case S_IFDIR: err = ovl_do_mkdir(dir, newdentry, attr->mode, debug); break; case S_IFCHR: case S_IFBLK: case S_IFIFO: case S_IFSOCK: err = ovl_do_mknod(dir, newdentry, attr->mode, attr->rdev, debug); break; case S_IFLNK: err = ovl_do_symlink(dir, newdentry, attr->link, debug); break; default: err = -EPERM; } } if (!err && WARN_ON(!newdentry->d_inode)) { /* * Not quite sure if non-instantiated dentry is legal or not. * VFS doesn't seem to care so check and warn here. */ err = -ENOENT; } return err; }

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static int ovl_set_opaque(struct dentry *dentry, struct dentry *upperdentry) { int err; err = ovl_do_setxattr(upperdentry, OVL_XATTR_OPAQUE, "y", 1, 0); if (!err) ovl_dentry_set_opaque(dentry); return err; }

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hujianyanghujianyang12.13%133.33%
Total47100.00%3100.00%


static int ovl_dir_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { int err; enum ovl_path_type type; struct path realpath; const struct cred *old_cred; type = ovl_path_real(dentry, &realpath); old_cred = ovl_override_creds(dentry->d_sb); err = vfs_getattr(&realpath, stat); revert_creds(old_cred); if (err) return err; stat->dev = dentry->d_sb->s_dev; stat->ino = dentry->d_inode->i_ino; /* * It's probably not worth it to count subdirs to get the * correct link count. nlink=1 seems to pacify 'find' and * other utilities. */ if (OVL_TYPE_MERGE(type)) stat->nlink = 1; return 0; }

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vivek goyalvivek goyal2017.24%133.33%
Total116100.00%3100.00%

/* Common operations required to be done after creation of file on upper */
static void ovl_instantiate(struct dentry *dentry, struct inode *inode, struct dentry *newdentry, bool hardlink) { ovl_dentry_version_inc(dentry->d_parent); ovl_dentry_update(dentry, newdentry); if (!hardlink) { ovl_inode_update(inode, d_inode(newdentry)); ovl_copyattr(newdentry->d_inode, inode); } else { WARN_ON(ovl_inode_real(inode, NULL) != d_inode(newdentry)); inc_nlink(inode); } d_instantiate(dentry, inode); }

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vivek goyalvivek goyal5154.26%133.33%
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Total94100.00%3100.00%


static bool ovl_type_merge(struct dentry *dentry) { return OVL_TYPE_MERGE(ovl_path_type(dentry)); }

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amir goldsteinamir goldstein20100.00%1100.00%
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static int ovl_create_upper(struct dentry *dentry, struct inode *inode, struct cattr *attr, struct dentry *hardlink) { struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); struct inode *udir = upperdir->d_inode; struct dentry *newdentry; int err; if (!hardlink && !IS_POSIXACL(udir)) attr->mode &= ~current_umask(); inode_lock_nested(udir, I_MUTEX_PARENT); newdentry = lookup_one_len(dentry->d_name.name, upperdir, dentry->d_name.len); err = PTR_ERR(newdentry); if (IS_ERR(newdentry)) goto out_unlock; err = ovl_create_real(udir, newdentry, attr, hardlink, false); if (err) goto out_dput; if (ovl_type_merge(dentry->d_parent)) { /* Setting opaque here is just an optimization, allow to fail */ ovl_set_opaque(dentry, newdentry); } ovl_instantiate(dentry, inode, newdentry, !!hardlink); newdentry = NULL; out_dput: dput(newdentry); out_unlock: inode_unlock(udir); return err; }

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miklos szeredimiklos szeredi16585.94%342.86%
amir goldsteinamir goldstein199.90%114.29%
al viroal viro63.12%228.57%
vivek goyalvivek goyal21.04%114.29%
Total192100.00%7100.00%


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; }

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static struct dentry *ovl_clear_empty(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 path upperpath; struct dentry *upper; struct dentry *opaquedir; struct kstat stat; int err; if (WARN_ON(!workdir)) return ERR_PTR(-EROFS); err = ovl_lock_rename_workdir(workdir, upperdir); if (err) goto out; ovl_path_upper(dentry, &upperpath); err = vfs_getattr(&upperpath, &stat); if (err) goto out_unlock; err = -ESTALE; if (!S_ISDIR(stat.mode)) goto out_unlock; upper = upperpath.dentry; if (upper->d_parent->d_inode != udir) goto out_unlock; opaquedir = ovl_lookup_temp(workdir, dentry); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) goto out_unlock; err = ovl_create_real(wdir, opaquedir, &(struct cattr){.mode = stat.mode}, NULL, true); if (err) goto out_dput; err = ovl_copy_xattr(upper, opaquedir); if (err) goto out_cleanup; err = ovl_set_opaque(dentry, opaquedir); if (err) goto out_cleanup; inode_lock(opaquedir->d_inode); err = ovl_set_attr(opaquedir, &stat); inode_unlock(opaquedir->d_inode); if (err) goto out_cleanup; err = ovl_do_rename(wdir, opaquedir, udir, upper, RENAME_EXCHANGE); if (err) goto out_cleanup; ovl_cleanup_whiteouts(upper, list); ovl_cleanup(wdir, upper); unlock_rename(workdir, upperdir); /* dentry's upper doesn't match now, get rid of it */ d_drop(dentry); return opaquedir; out_cleanup: ovl_cleanup(wdir, opaquedir); out_dput: dput(opaquedir); out_unlock: unlock_rename(workdir, upperdir); out: return ERR_PTR(err); }

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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; }

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static int ovl_set_upper_acl(struct dentry *upperdentry, const char *name, const struct posix_acl *acl) { void *buffer; size_t size; int err; if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !acl) return 0; size = posix_acl_to_xattr(NULL, acl, NULL, 0); buffer = kmalloc(size, GFP_KERNEL); if (!buffer) return -ENOMEM; size = posix_acl_to_xattr(&init_user_ns, acl, buffer, size); err = size; if (err < 0) goto out_free; err = vfs_setxattr(upperdentry, name, buffer, size, XATTR_CREATE); out_free: kfree(buffer); return err; }

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static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode, struct cattr *cattr, struct dentry *hardlink) { 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 *upper; struct dentry *newdentry; int err; struct posix_acl *acl, *default_acl; if (WARN_ON(!workdir)) return -EROFS; if (!hardlink) { err = posix_acl_create(dentry->d_parent->d_inode, &cattr->mode, &default_acl, &acl); if (err) return err; } err = ovl_lock_rename_workdir(workdir, upperdir); if (err) goto out; newdentry = ovl_lookup_temp(workdir, dentry); err = PTR_ERR(newdentry); if (IS_ERR(newdentry)) goto out_unlock; upper = lookup_one_len(dentry->d_name.name, upperdir, dentry->d_name.len); err = PTR_ERR(upper); if (IS_ERR(upper)) goto out_dput; err = ovl_create_real(wdir, newdentry, cattr, hardlink, true); if (err) goto out_dput2; /* * mode could have been mutilated due to umask (e.g. sgid directory) */ if (!hardlink && !S_ISLNK(cattr->mode) && newdentry->d_inode->i_mode != cattr->mode) { struct iattr attr = { .ia_valid = ATTR_MODE, .ia_mode = cattr->mode, }; inode_lock(newdentry->d_inode); err = notify_change(newdentry, &attr, NULL); inode_unlock(newdentry->d_inode); if (err) goto out_cleanup; } if (!hardlink) { err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_ACCESS, acl); if (err) goto out_cleanup; err = ovl_set_upper_acl(newdentry, XATTR_NAME_POSIX_ACL_DEFAULT, default_acl); if (err) goto out_cleanup; } if (!hardlink && S_ISDIR(cattr->mode)) { err = ovl_set_opaque(dentry, newdentry); if (err) goto out_cleanup; err = ovl_do_rename(wdir, newdentry, udir, upper, RENAME_EXCHANGE); if (err) goto out_cleanup; ovl_cleanup(wdir, upper); } else { err = ovl_do_rename(wdir, newdentry, udir, upper, 0); if (err) goto out_cleanup; } ovl_instantiate(dentry, inode, newdentry, !!hardlink); newdentry = NULL; out_dput2: dput(upper); out_dput: dput(newdentry); out_unlock: unlock_rename(workdir, upperdir); out: if (!hardlink) { posix_acl_release(acl); posix_acl_release(default_acl); } return err; out_cleanup: ovl_cleanup(wdir, newdentry); goto out_dput2; }

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vivek goyalvivek goyal20.39%112.50%
Total513100.00%8100.00%


static int ovl_create_or_link(struct dentry *dentry, struct inode *inode, struct cattr *attr, struct dentry *hardlink) { int err; const struct cred *old_cred; struct cred *override_cred; err = ovl_copy_up(dentry->d_parent); if (err) return err; old_cred = ovl_override_creds(dentry->d_sb); err = -ENOMEM; override_cred = prepare_creds(); if (override_cred) { override_cred->fsuid = inode->i_uid; override_cred->fsgid = inode->i_gid; if (!hardlink) { err = security_dentry_create_files_as(dentry, attr->mode, &dentry->d_name, old_cred, override_cred); if (err) { put_cred(override_cred); goto out_revert_creds; } } put_cred(override_creds(override_cred)); put_cred(override_cred); if (!ovl_dentry_is_whiteout(dentry)) err = ovl_create_upper(dentry, inode, attr, hardlink); else err = ovl_create_over_whiteout(dentry, inode, attr, hardlink); } out_revert_creds: revert_creds(old_cred); if (!err) { struct inode *realinode = d_inode(ovl_dentry_upper(dentry)); WARN_ON(inode->i_mode != realinode->i_mode); WARN_ON(!uid_eq(inode->i_uid, realinode->i_uid)); WARN_ON(!gid_eq(inode->i_gid, realinode->i_gid)); } return err; }

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vivek goyalvivek goyal7328.40%222.22%
al viroal viro51.95%111.11%
antonio murdacaantonio murdaca41.56%111.11%
Total257100.00%9100.00%


static int ovl_create_object(struct dentry *dentry, int mode, dev_t rdev, const char *link) { int err; struct inode *inode; struct cattr attr = { .rdev = rdev, .link = link, }; err = ovl_want_write(dentry); if (err) goto out; err = -ENOMEM; inode = ovl_new_inode(dentry->d_sb, mode, rdev); if (!inode) goto out_drop_write; inode_init_owner(inode, dentry->d_parent->d_inode, mode); attr.mode = inode->i_mode; err = ovl_create_or_link(dentry, inode, &attr, NULL); if (err) iput(inode); out_drop_write: ovl_drop_write(dentry); out: return err; }

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static int ovl_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL); }

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static int ovl_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL); }

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static int ovl_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) { /* Don't allow creation of "whiteout" on overlay */ if (S_ISCHR(mode) && rdev == WHITEOUT_DEV) return -EPERM; return ovl_create_object(dentry, mode, rdev, NULL); }

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static int ovl_symlink(struct inode *dir, struct dentry *dentry, const char *link) { return ovl_create_object(dentry, S_IFLNK, 0, link); }

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static int ovl_link(struct dentry *old, struct inode *newdir, struct dentry *new) { int err; struct inode *inode; err = ovl_want_write(old); if (err) goto out; err = ovl_copy_up(old); if (err) goto out_drop_write; inode = d_inode(old); ihold(inode); err = ovl_create_or_link(new, inode, NULL, ovl_dentry_upper(old)); if (err) iput(inode); out_drop_write: ovl_drop_write(old); out: return err; }

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static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir) { 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); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) goto out; } err = ovl_lock_rename_workdir(workdir, upperdir); if (err) goto out_dput; upper = lookup_one_len(dentry->d_name.name, upperdir, dentry->d_name.len); err = PTR_ERR(upper); if (IS_ERR(upper)) goto out_unlock; err = -ESTALE; if ((opaquedir && upper != opaquedir) || (!opaquedir && ovl_dentry_upper(dentry) && upper != ovl_dentry_upper(dentry))) { 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); if (err) goto kill_whiteout; if (flags) ovl_cleanup(wdir, upper); ovl_dentry_version_inc(dentry->d_parent); out_d_drop: d_drop(dentry); dput(whiteout); out_dput_upper: dput(upper); out_unlock: unlock_rename(workdir, upperdir); out_dput: dput(opaquedir); out: return err; kill_whiteout: ovl_cleanup(wdir, whiteout); goto out_d_drop; }

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miklos szeredimiklos szeredi27781.71%375.00%
maxim patlasovmaxim patlasov6218.29%125.00%
Total339100.00%4100.00%


static int ovl_remove_upper(struct dentry *dentry, bool is_dir) { struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); struct inode *dir = upperdir->d_inode; struct dentry *upper; 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); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) goto out; } inode_lock_nested(dir, I_MUTEX_PARENT); upper = lookup_one_len(dentry->d_name.name, upperdir, dentry->d_name.len); err = PTR_ERR(upper); if (IS_ERR(upper)) goto out_unlock; err = -ESTALE; if ((opaquedir && upper != opaquedir) || (!opaquedir && upper != ovl_dentry_upper(dentry))) goto out_dput_upper; if (is_dir) err = vfs_rmdir(dir, upper); else err = vfs_unlink(dir, upper, NULL); ovl_dentry_version_inc(dentry->d_parent); /* * Keeping this dentry hashed would mean having to release * upperpath/lowerpath, which could only be done if we are the * sole user of this dentry. Too tricky... Just unhash for * now. */ if (!err) d_drop(dentry); out_dput_upper: dput(upper); out_unlock: inode_unlock(dir); dput(opaquedir); out: return err; }

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miklos szeredimiklos szeredi14564.16%240.00%
amir goldsteinamir goldstein7432.74%120.00%
rui wangrui wang52.21%120.00%
al viroal viro20.88%120.00%
Total226100.00%5100.00%


static int ovl_do_remove(struct dentry *dentry, bool is_dir) { enum ovl_path_type type; int err; const struct cred *old_cred; err = ovl_want_write(dentry); if (err) goto out; err = ovl_copy_up(dentry->d_parent); if (err) goto out_drop_write; type = ovl_path_type(dentry); old_cred = ovl_override_creds(dentry->d_sb); if (!ovl_lower_positive(dentry)) err = ovl_remove_upper(dentry, is_dir); else err = ovl_remove_and_whiteout(dentry, is_dir); revert_creds(old_cred); if (!err) { if (is_dir) clear_nlink(dentry->d_inode); else drop_nlink(dentry->d_inode); } out_drop_write: ovl_drop_write(dentry); out: return err; }

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vivek goyalvivek goyal1510.49%116.67%
Total143100.00%6100.00%


static int ovl_unlink(struct inode *dir, struct dentry *dentry) { return ovl_do_remove(dentry, false); }

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static int ovl_rmdir(struct inode *dir, struct dentry *dentry) { return ovl_do_remove(dentry, true); }

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static bool ovl_type_merge_or_lower(struct dentry *dentry) { enum ovl_path_type type = ovl_path_type(dentry); return OVL_TYPE_MERGE(type) || !OVL_TYPE_UPPER(type); }

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static bool ovl_can_move(struct dentry *dentry) { return ovl_redirect_dir(dentry->d_sb) || !d_is_dir(dentry) || !ovl_type_merge_or_lower(dentry); }

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miklos szeredimiklos szeredi31100.00%1100.00%
Total31100.00%1100.00%


static char *ovl_get_redirect(struct dentry *dentry, bool samedir) { char *buf, *ret; struct dentry *d, *tmp; int buflen = ovl_redirect_max + 1; if (samedir) { ret = kstrndup(dentry->d_name.name, dentry->d_name.len, GFP_KERNEL); goto out; } buf = ret = kmalloc(buflen, GFP_TEMPORARY); if (!buf) goto out; buflen--; buf[buflen] = '\0'; for (d = dget(dentry); !IS_ROOT(d);) { const char *name; int thislen; spin_lock(&d->d_lock); name = ovl_dentry_get_redirect(d); if (name) { thislen = strlen(name); } else { name = d->d_name.name; thislen = d->d_name.len; } /* If path is too long, fall back to userspace move */ if (thislen + (name[0] != '/') > buflen) { ret = ERR_PTR(-EXDEV); spin_unlock(&d->d_lock); goto out_put; } buflen -= thislen; memcpy(&buf[buflen], name, thislen); tmp = dget_dlock(d->d_parent); spin_unlock(&d->d_lock); dput(d); d = tmp; /* Absolute redirect: finished */ if (buf[buflen] == '/') break; buflen--; buf[buflen] = '/'; } ret = kstrdup(&buf[buflen], GFP_KERNEL); out_put: dput(d); kfree(buf); out: return ret ? ret : ERR_PTR(-ENOMEM); }

Contributors

PersonTokensPropCommitsCommitProp
miklos szeredimiklos szeredi306100.00%2100.00%
Total306100.00%2100.00%


static int ovl_set_redirect(struct dentry *dentry, bool samedir) { int err; const char *redirect = ovl_dentry_get_redirect(dentry); if (redirect && (samedir || redirect[0] == '/')) return 0; redirect = ovl_get_redirect(dentry, samedir); if (IS_ERR(redirect)) return PTR_ERR(redirect); err = ovl_do_setxattr(ovl_dentry_upper(dentry), OVL_XATTR_REDIRECT, redirect, strlen(redirect), 0); if (!err) { spin_lock(&dentry->d_lock); ovl_dentry_set_redirect(dentry, redirect); spin_unlock(&dentry->d_lock); } else { kfree(redirect); if (err == -EOPNOTSUPP) ovl_clear_redirect_dir(dentry->d_sb); else pr_warn_ratelimited("overlay: failed to set redirect (%i)\n", err); /* Fall back to userspace copy-up */ err = -EXDEV; } return err; }

Contributors

PersonTokensPropCommitsCommitProp
miklos szeredimiklos szeredi157100.00%1100.00%
Total157100.00%1100.00%


static int ovl_rename(struct inode *olddir, struct dentry *old, struct inode *newdir, struct dentry *new, unsigned int flags) { int err; struct dentry *old_upperdir; struct dentry *new_upperdir; struct dentry *olddentry; struct dentry *newdentry; struct dentry *trap; bool old_opaque; bool new_opaque; bool cleanup_whiteout = false; bool overwrite = !(flags & RENAME_EXCHANGE); bool is_dir = d_is_dir(old); bool new_is_dir = d_is_dir(new); bool samedir = olddir == newdir; struct dentry *opaquedir = NULL; const struct cred *old_cred = NULL; err = -EINVAL; if (flags & ~(RENAME_EXCHANGE | RENAME_NOREPLACE)) goto out; flags &= ~RENAME_NOREPLACE; /* Don't copy up directory trees */ err = -EXDEV; if (!ovl_can_move(old)) goto out; if (!overwrite && !ovl_can_move(new)) goto out; err = ovl_want_write(old); if (err) goto out; err = ovl_copy_up(old); if (err) goto out_drop_write; err = ovl_copy_up(new->d_parent); if (err) goto out_drop_write; if (!overwrite) { err = ovl_copy_up(new); if (err) goto out_drop_write; } 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); err = PTR_ERR(opaquedir); if (IS_ERR(opaquedir)) { opaquedir = NULL; goto out_revert_creds; } } 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); trap = lock_rename(new_upperdir, old_upperdir); olddentry = lookup_one_len(old->d_name.name, old_upperdir, old->d_name.len); err = PTR_ERR(olddentry); if (IS_ERR(olddentry)) goto out_unlock; err = -ESTALE; if (olddentry != ovl_dentry_upper(old)) goto out_dput_old; newdentry = lookup_one_len(new->d_name.name, new_upperdir, new->d_name.len); err = PTR_ERR(newdentry); if (IS_ERR(newdentry)) goto out_dput_old; old_opaque = ovl_dentry_is_opaque(old); new_opaque = ovl_dentry_is_opaque(new); err = -ESTALE; if (ovl_dentry_upper(new)) { if (opaquedir) { if (newdentry != opaquedir) goto out_dput; } else { if (newdentry != ovl_dentry_upper(new)) goto out_dput; } } else { if (!d_is_negative(newdentry) && (!new_opaque || !ovl_is_whiteout(newdentry))) goto out_dput; } if (olddentry == trap) goto out_dput; if (newdentry == trap) goto out_dput; if (WARN_ON(olddentry->d_inode == newdentry->d_inode)) goto out_dput; err = 0; if (is_dir) { if (ovl_type_merge_or_lower(old)) err = ovl_set_redirect(old, samedir); else if (!old_opaque && ovl_type_merge(new->d_parent)) err = ovl_set_opaque(old, olddentry); if (err) goto out_dput; } if (!overwrite && new_is_dir) { if (ovl_type_merge_or_lower(new)) err = ovl_set_redirect(new, samedir); else if (!new_opaque && ovl_type_merge(old->d_parent)) err = ovl_set_opaque(new, newdentry); if (err) goto out_dput; } err = ovl_do_rename(old_upperdir->d_inode, olddentry, new_upperdir->d_inode, newdentry, flags); if (err) goto out_dput; if (cleanup_whiteout) ovl_cleanup(old_upperdir->d_inode, newdentry); ovl_dentry_version_inc(old->d_parent); ovl_dentry_version_inc(new->d_parent); out_dput: dput(newdentry); out_dput_old: dput(olddentry); out_unlock: unlock_rename(new_upperdir, old_upperdir); out_revert_creds: revert_creds(old_cred); out_drop_write: ovl_drop_write(old); out: dput(opaquedir); return err; }

Contributors

PersonTokensPropCommitsCommitProp
miklos szeredimiklos szeredi77898.61%1178.57%
amir goldsteinamir goldstein60.76%17.14%
antonio murdacaantonio murdaca40.51%17.14%
david howellsdavid howells10.13%17.14%
Total789100.00%14100.00%

const struct inode_operations ovl_dir_inode_operations = { .lookup = ovl_lookup, .mkdir = ovl_mkdir, .symlink = ovl_symlink, .unlink = ovl_unlink, .rmdir = ovl_rmdir, .rename = ovl_rename, .link = ovl_link, .setattr = ovl_setattr, .create = ovl_create, .mknod = ovl_mknod, .permission = ovl_permission, .getattr = ovl_dir_getattr, .listxattr = ovl_listxattr, .get_acl = ovl_get_acl, .update_time = ovl_update_time, };

Overall Contributors

PersonTokensPropCommitsCommitProp
miklos szeredimiklos szeredi454991.27%2564.10%
vivek goyalvivek goyal1673.35%410.26%
amir goldsteinamir goldstein1192.39%25.13%
maxim patlasovmaxim patlasov621.24%12.56%
al viroal viro521.04%25.13%
richard weinbergerrichard weinberger190.38%12.56%
antonio murdacaantonio murdaca80.16%12.56%
rui wangrui wang50.10%12.56%
david howellsdavid howells20.04%12.56%
hujianyanghujianyang10.02%12.56%
Total4984100.00%39100.00%
Directory: fs/overlayfs
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