^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Copyright (C) 2011 Novell Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (C) 2016 Red Hat, Inc.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) #include <linux/cred.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) #include <linux/ctype.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/namei.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/xattr.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/ratelimit.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/exportfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include "overlayfs.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) struct ovl_lookup_data {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) struct super_block *sb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) struct qstr name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) bool is_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) bool opaque;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) bool stop;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) bool last;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) char *redirect;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) bool metacopy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static int ovl_check_redirect(struct dentry *dentry, struct ovl_lookup_data *d,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) size_t prelen, const char *post)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) int res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) char *buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) struct ovl_fs *ofs = OVL_FS(d->sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) buf = ovl_get_redirect_xattr(ofs, dentry, prelen + strlen(post));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) if (IS_ERR_OR_NULL(buf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) return PTR_ERR(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) if (buf[0] == '/') {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * One of the ancestor path elements in an absolute path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * lookup in ovl_lookup_layer() could have been opaque and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) * that will stop further lookup in lower layers (d->stop=true)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * But we have found an absolute redirect in decendant path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * element and that should force continue lookup in lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * layers (reset d->stop).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) d->stop = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) res = strlen(buf) + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) memmove(buf + prelen, buf, res);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) memcpy(buf, d->name.name, prelen);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) strcat(buf, post);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) kfree(d->redirect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) d->redirect = buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) d->name.name = d->redirect;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) d->name.len = strlen(d->redirect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) static int ovl_acceptable(void *ctx, struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) * A non-dir origin may be disconnected, which is fine, because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) * we only need it for its unique inode number.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) if (!d_is_dir(dentry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) /* Don't decode a deleted empty directory */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (d_unhashed(dentry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) /* Check if directory belongs to the layer we are decoding from */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) return is_subdir(dentry, ((struct vfsmount *)ctx)->mnt_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) * Check validity of an overlay file handle buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) * Return 0 for a valid file handle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) * Return -ENODATA for "origin unknown".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * Return <0 for an invalid file handle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) int ovl_check_fb_len(struct ovl_fb *fb, int fb_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (fb_len < sizeof(struct ovl_fb) || fb_len < fb->len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) if (fb->magic != OVL_FH_MAGIC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) /* Treat larger version and unknown flags as "origin unknown" */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) if (fb->version > OVL_FH_VERSION || fb->flags & ~OVL_FH_FLAG_ALL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) return -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) /* Treat endianness mismatch as "origin unknown" */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) if (!(fb->flags & OVL_FH_FLAG_ANY_ENDIAN) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) (fb->flags & OVL_FH_FLAG_BIG_ENDIAN) != OVL_FH_FLAG_CPU_ENDIAN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) return -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) static struct ovl_fh *ovl_get_fh(struct ovl_fs *ofs, struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) enum ovl_xattr ox)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) ssize_t res;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) struct ovl_fh *fh = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) res = ovl_do_getxattr(ofs, dentry, ox, NULL, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) if (res < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) if (res == -ENODATA || res == -EOPNOTSUPP)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) /* Zero size value means "copied up but origin unknown" */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) if (res == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) fh = kzalloc(res + OVL_FH_WIRE_OFFSET, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) if (!fh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) res = ovl_do_getxattr(ofs, dentry, ox, fh->buf, res);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) if (res < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) err = ovl_check_fb_len(&fh->fb, res);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) if (err < 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (err == -ENODATA)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) goto invalid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) return fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) kfree(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) pr_warn_ratelimited("failed to get origin (%zi)\n", res);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) invalid:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) pr_warn_ratelimited("invalid origin (%*phN)\n", (int)res, fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) bool connected)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) struct dentry *real;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) int bytes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * Make sure that the stored uuid matches the uuid of the lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) * layer where file handle will be decoded.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) if (!uuid_equal(&fh->fb.uuid, &mnt->mnt_sb->s_uuid))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) bytes = (fh->fb.len - offsetof(struct ovl_fb, fid));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) real = exportfs_decode_fh(mnt, (struct fid *)fh->fb.fid,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) bytes >> 2, (int)fh->fb.type,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) connected ? ovl_acceptable : NULL, mnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) if (IS_ERR(real)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) * Treat stale file handle to lower file as "origin unknown".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) * upper file handle could become stale when upper file is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * unlinked and this information is needed to handle stale
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) * index entries correctly.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) if (real == ERR_PTR(-ESTALE) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) !(fh->fb.flags & OVL_FH_FLAG_PATH_UPPER))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) real = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) return real;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) if (ovl_dentry_weird(real)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) dput(real);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) return real;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) static bool ovl_is_opaquedir(struct super_block *sb, struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) return ovl_check_dir_xattr(sb, dentry, OVL_XATTR_OPAQUE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) static struct dentry *ovl_lookup_positive_unlocked(const char *name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) struct dentry *base, int len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) bool drop_negative)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) struct dentry *ret = lookup_one_len_unlocked(name, base, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) if (!IS_ERR(ret) && d_flags_negative(smp_load_acquire(&ret->d_flags))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) if (drop_negative && ret->d_lockref.count == 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) spin_lock(&ret->d_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) /* Recheck condition under lock */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) if (d_is_negative(ret) && ret->d_lockref.count == 1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) __d_drop(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) spin_unlock(&ret->d_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) dput(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) ret = ERR_PTR(-ENOENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) const char *name, unsigned int namelen,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) size_t prelen, const char *post,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) struct dentry **ret, bool drop_negative)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) struct dentry *this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) bool last_element = !post[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) this = ovl_lookup_positive_unlocked(name, base, namelen, drop_negative);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) if (IS_ERR(this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) err = PTR_ERR(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) this = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) if (err == -ENOENT || err == -ENAMETOOLONG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) if (ovl_dentry_weird(this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) /* Don't support traversing automounts and other weirdness */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) err = -EREMOTE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) if (ovl_is_whiteout(this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) d->stop = d->opaque = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) goto put_and_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) * This dentry should be a regular file if previous layer lookup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) * found a metacopy dentry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) if (last_element && d->metacopy && !d_is_reg(this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) d->stop = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) goto put_and_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) if (!d_can_lookup(this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) if (d->is_dir || !last_element) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) d->stop = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) goto put_and_out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) err = ovl_check_metacopy_xattr(OVL_FS(d->sb), this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) d->metacopy = err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) d->stop = !d->metacopy;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) if (!d->metacopy || d->last)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) if (ovl_lookup_trap_inode(d->sb, this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) /* Caught in a trap of overlapping layers */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) err = -ELOOP;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) if (last_element)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) d->is_dir = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) if (d->last)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) if (ovl_is_opaquedir(d->sb, this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) d->stop = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) if (last_element)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) d->opaque = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) err = ovl_check_redirect(this, d, prelen, post);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) goto out_err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) *ret = this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) put_and_out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) dput(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) this = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) out_err:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) dput(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) static int ovl_lookup_layer(struct dentry *base, struct ovl_lookup_data *d,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) struct dentry **ret, bool drop_negative)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) /* Counting down from the end, since the prefix can change */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) size_t rem = d->name.len - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) struct dentry *dentry = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) if (d->name.name[0] != '/')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) return ovl_lookup_single(base, d, d->name.name, d->name.len,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 0, "", ret, drop_negative);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) while (!IS_ERR_OR_NULL(base) && d_can_lookup(base)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) const char *s = d->name.name + d->name.len - rem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) const char *next = strchrnul(s, '/');
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) size_t thislen = next - s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) bool end = !next[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) /* Verify we did not go off the rails */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) if (WARN_ON(s[-1] != '/'))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) err = ovl_lookup_single(base, d, s, thislen,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) d->name.len - rem, next, &base,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) drop_negative);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) dput(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) dentry = base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) if (end)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) rem -= thislen + 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) if (WARN_ON(rem >= d->name.len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) *ret = dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) struct dentry *upperdentry, struct ovl_path **stackp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) struct dentry *origin = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) for (i = 1; i < ofs->numlayer; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) * If lower fs uuid is not unique among lower fs we cannot match
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) * fh->uuid to layer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) if (ofs->layers[i].fsid &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) ofs->layers[i].fs->bad_uuid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) origin = ovl_decode_real_fh(fh, ofs->layers[i].mnt,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) connected);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) if (origin)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) if (!origin)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) return -ESTALE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) else if (IS_ERR(origin))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) return PTR_ERR(origin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) if (upperdentry && !ovl_is_whiteout(upperdentry) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) inode_wrong_type(d_inode(upperdentry), d_inode(origin)->i_mode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) goto invalid;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) if (!*stackp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) *stackp = kmalloc(sizeof(struct ovl_path), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) if (!*stackp) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) dput(origin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) **stackp = (struct ovl_path){
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) .dentry = origin,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) .layer = &ofs->layers[i]
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) invalid:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) pr_warn_ratelimited("invalid origin (%pd2, ftype=%x, origin ftype=%x).\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) upperdentry, d_inode(upperdentry)->i_mode & S_IFMT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) d_inode(origin)->i_mode & S_IFMT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) dput(origin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) return -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) struct ovl_path **stackp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) struct ovl_fh *fh = ovl_get_fh(ofs, upperdentry, OVL_XATTR_ORIGIN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) if (IS_ERR_OR_NULL(fh))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) return PTR_ERR(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) err = ovl_check_origin_fh(ofs, fh, false, upperdentry, stackp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) kfree(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) if (err == -ESTALE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * Verify that @fh matches the file handle stored in xattr @name.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * Return 0 on match, -ESTALE on mismatch, < 0 on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) static int ovl_verify_fh(struct ovl_fs *ofs, struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) enum ovl_xattr ox, const struct ovl_fh *fh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) struct ovl_fh *ofh = ovl_get_fh(ofs, dentry, ox);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) if (!ofh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) return -ENODATA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) if (IS_ERR(ofh))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) return PTR_ERR(ofh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) if (fh->fb.len != ofh->fb.len || memcmp(&fh->fb, &ofh->fb, fh->fb.len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) err = -ESTALE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) kfree(ofh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) * Verify that @real dentry matches the file handle stored in xattr @name.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) * If @set is true and there is no stored file handle, encode @real and store
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) * file handle in xattr @name.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) * Return 0 on match, -ESTALE on mismatch, -ENODATA on no xattr, < 0 on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) int ovl_verify_set_fh(struct ovl_fs *ofs, struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) enum ovl_xattr ox, struct dentry *real, bool is_upper,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) bool set)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) struct ovl_fh *fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) fh = ovl_encode_real_fh(real, is_upper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) err = PTR_ERR(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) if (IS_ERR(fh)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) fh = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) err = ovl_verify_fh(ofs, dentry, ox, fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) if (set && err == -ENODATA)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) err = ovl_do_setxattr(ofs, dentry, ox, fh->buf, fh->fb.len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) kfree(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) inode = d_inode(real);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) pr_warn_ratelimited("failed to verify %s (%pd2, ino=%lu, err=%i)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) is_upper ? "upper" : "origin", real,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) inode ? inode->i_ino : 0, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) /* Get upper dentry from index */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482) struct ovl_fh *fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) struct dentry *upper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) if (!d_is_dir(index))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) return dget(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) fh = ovl_get_fh(ofs, index, OVL_XATTR_UPPER);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) if (IS_ERR_OR_NULL(fh))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) return ERR_CAST(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) upper = ovl_decode_real_fh(fh, ovl_upper_mnt(ofs), true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) kfree(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) if (IS_ERR_OR_NULL(upper))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) return upper ?: ERR_PTR(-ESTALE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) if (!d_is_dir(upper)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) pr_warn_ratelimited("invalid index upper (%pd2, upper=%pd2).\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) index, upper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) dput(upper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) return ERR_PTR(-EIO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) return upper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) * Verify that an index entry name matches the origin file handle stored in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) * OVL_XATTR_ORIGIN and that origin file handle can be decoded to lower path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) * Return 0 on match, -ESTALE on mismatch or stale origin, < 0 on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) struct ovl_fh *fh = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) size_t len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) struct ovl_path origin = { };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) struct ovl_path *stack = &origin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) struct dentry *upper = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) if (!d_inode(index))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) if (index->d_name.len < sizeof(struct ovl_fb)*2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) len = index->d_name.len / 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) fh = kzalloc(len + OVL_FH_WIRE_OFFSET, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) if (!fh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) err = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) if (hex2bin(fh->buf, index->d_name.name, len))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) err = ovl_check_fb_len(&fh->fb, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) * Whiteout index entries are used as an indication that an exported
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) * overlay file handle should be treated as stale (i.e. after unlink
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) * of the overlay inode). These entries contain no origin xattr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) if (ovl_is_whiteout(index))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) * Verifying directory index entries are not stale is expensive, so
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) * only verify stale dir index if NFS export is enabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) if (d_is_dir(index) && !ofs->config.nfs_export)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) * Directory index entries should have 'upper' xattr pointing to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) * real upper dir. Non-dir index entries are hardlinks to the upper
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) * real inode. For non-dir index, we can read the copy up origin xattr
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) * directly from the index dentry, but for dir index we first need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) * decode the upper directory.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) upper = ovl_index_upper(ofs, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) if (IS_ERR_OR_NULL(upper)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) err = PTR_ERR(upper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) * Directory index entries with no 'upper' xattr need to be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) * removed. When dir index entry has a stale 'upper' xattr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) * we assume that upper dir was removed and we treat the dir
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) * index as orphan entry that needs to be whited out.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) if (err == -ESTALE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) goto orphan;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) else if (!err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) err = -ESTALE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) err = ovl_verify_fh(ofs, upper, OVL_XATTR_ORIGIN, fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) dput(upper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) /* Check if non-dir index is orphan and don't warn before cleaning it */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) if (!d_is_dir(index) && d_inode(index)->i_nlink == 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) err = ovl_check_origin_fh(ofs, fh, false, index, &stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) if (ovl_get_nlink(ofs, origin.dentry, index, 0) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) goto orphan;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) dput(origin.dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) kfree(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) pr_warn_ratelimited("failed to verify index (%pd2, ftype=%x, err=%i)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) index, d_inode(index)->i_mode & S_IFMT, err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) orphan:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) pr_warn_ratelimited("orphan index entry (%pd2, ftype=%x, nlink=%u)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) index, d_inode(index)->i_mode & S_IFMT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) d_inode(index)->i_nlink);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) err = -ENOENT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) static int ovl_get_index_name_fh(struct ovl_fh *fh, struct qstr *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) char *n, *s;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) n = kcalloc(fh->fb.len, 2, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) if (!n)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) s = bin2hex(n, fh->buf, fh->fb.len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) *name = (struct qstr) QSTR_INIT(n, s - n);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) * Lookup in indexdir for the index entry of a lower real inode or a copy up
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) * origin inode. The index entry name is the hex representation of the lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) * inode file handle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) * If the index dentry in negative, then either no lower aliases have been
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) * copied up yet, or aliases have been copied up in older kernels and are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) * not indexed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) * If the index dentry for a copy up origin inode is positive, but points
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) * to an inode different than the upper inode, then either the upper inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) * has been copied up and not indexed or it was indexed, but since then
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) * index dir was cleared. Either way, that index cannot be used to indentify
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) * the overlay inode.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) int ovl_get_index_name(struct dentry *origin, struct qstr *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) struct ovl_fh *fh;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) fh = ovl_encode_real_fh(origin, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) if (IS_ERR(fh))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) return PTR_ERR(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) err = ovl_get_index_name_fh(fh, name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) kfree(fh);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) /* Lookup index by file handle for NFS export */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) struct dentry *ovl_get_index_fh(struct ovl_fs *ofs, struct ovl_fh *fh)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) struct dentry *index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) struct qstr name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) err = ovl_get_index_name_fh(fh, &name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) index = lookup_positive_unlocked(name.name, ofs->indexdir, name.len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) kfree(name.name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) if (IS_ERR(index)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) if (PTR_ERR(index) == -ENOENT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) index = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) return index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) if (ovl_is_whiteout(index))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) err = -ESTALE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) else if (ovl_dentry_weird(index))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) return index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) dput(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) struct dentry *origin, bool verify)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) struct dentry *index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) struct inode *inode;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) struct qstr name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) bool is_dir = d_is_dir(origin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) err = ovl_get_index_name(origin, &name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) index = lookup_positive_unlocked(name.name, ofs->indexdir, name.len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) if (IS_ERR(index)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) err = PTR_ERR(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) if (err == -ENOENT) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) index = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) pr_warn_ratelimited("failed inode index lookup (ino=%lu, key=%.*s, err=%i);\n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) "overlayfs: mount with '-o index=off' to disable inodes index.\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) d_inode(origin)->i_ino, name.len, name.name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) inode = d_inode(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) if (ovl_is_whiteout(index) && !verify) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) * When index lookup is called with !verify for decoding an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) * overlay file handle, a whiteout index implies that decode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721) * should treat file handle as stale and no need to print a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) * warning about it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) dput(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) index = ERR_PTR(-ESTALE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) } else if (ovl_dentry_weird(index) || ovl_is_whiteout(index) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) inode_wrong_type(inode, d_inode(origin)->i_mode)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) * Index should always be of the same file type as origin
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) * except for the case of a whiteout index. A whiteout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) * index should only exist if all lower aliases have been
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) * unlinked, which means that finding a lower origin on lookup
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) * whose index is a whiteout should be treated as an error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) pr_warn_ratelimited("bad index found (index=%pd2, ftype=%x, origin ftype=%x).\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) index, d_inode(index)->i_mode & S_IFMT,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) d_inode(origin)->i_mode & S_IFMT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) } else if (is_dir && verify) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) if (!upper) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) pr_warn_ratelimited("suspected uncovered redirected dir found (origin=%pd2, index=%pd2).\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) origin, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) /* Verify that dir index 'upper' xattr points to upper dir */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) err = ovl_verify_upper(ofs, index, upper, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) if (err == -ESTALE) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) pr_warn_ratelimited("suspected multiply redirected dir found (upper=%pd2, origin=%pd2, index=%pd2).\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752) upper, origin, index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) goto fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) } else if (upper && d_inode(upper) != inode) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) goto out_dput;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) kfree(name.name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) return index;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) out_dput:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) dput(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) index = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) dput(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) index = ERR_PTR(-EIO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) * Returns next layer in stack starting from top.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) * Returns -1 if this is the last layer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) int ovl_path_next(int idx, struct dentry *dentry, struct path *path)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) struct ovl_entry *oe = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) BUG_ON(idx < 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783) if (idx == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) ovl_path_upper(dentry, path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) if (path->dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) return oe->numlower ? 1 : -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) idx++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) BUG_ON(idx > oe->numlower);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) path->dentry = oe->lowerstack[idx - 1].dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791) path->mnt = oe->lowerstack[idx - 1].layer->mnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) return (idx < oe->numlower) ? idx + 1 : -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) /* Fix missing 'origin' xattr */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) static int ovl_fix_origin(struct ovl_fs *ofs, struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798) struct dentry *lower, struct dentry *upper)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) if (ovl_check_origin_xattr(ofs, upper))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) err = ovl_want_write(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) err = ovl_set_origin(dentry, lower, upper);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) if (!err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) err = ovl_set_impure(dentry->d_parent, upper->d_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) ovl_drop_write(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817) struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) unsigned int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) struct ovl_entry *oe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) const struct cred *old_cred;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823) struct ovl_entry *poe = dentry->d_parent->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) struct ovl_entry *roe = dentry->d_sb->s_root->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) struct ovl_path *stack = NULL, *origin_path = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) struct dentry *upperdir, *upperdentry = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) struct dentry *origin = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) struct dentry *index = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829) unsigned int ctr = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) struct inode *inode = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) bool upperopaque = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832) char *upperredirect = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) struct dentry *this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) unsigned int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835) int err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) bool uppermetacopy = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) struct ovl_lookup_data d = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) .sb = dentry->d_sb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) .name = dentry->d_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) .is_dir = false,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) .opaque = false,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) .stop = false,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843) .last = ofs->config.redirect_follow ? false : !poe->numlower,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) .redirect = NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) .metacopy = false,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) if (dentry->d_name.len > ofs->namelen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) return ERR_PTR(-ENAMETOOLONG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) old_cred = ovl_override_creds(dentry->d_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852) upperdir = ovl_dentry_upper(dentry->d_parent);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) if (upperdir) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) err = ovl_lookup_layer(upperdir, &d, &upperdentry, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) if (upperdentry && upperdentry->d_flags & DCACHE_OP_REAL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) dput(upperdentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) err = -EREMOTE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) if (upperdentry && !d.is_dir) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) * Lookup copy up origin by decoding origin file handle.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) * We may get a disconnected dentry, which is fine,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) * because we only need to hold the origin inode in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868) * cache and use its inode number. We may even get a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) * connected dentry, that is not under any of the lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) * layers root. That is also fine for using it's inode
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) * number - it's the same as if we held a reference
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) * to a dentry in lower layer that was moved under us.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) err = ovl_check_origin(ofs, upperdentry, &origin_path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) goto out_put_upper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) if (d.metacopy)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879) uppermetacopy = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882) if (d.redirect) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) upperredirect = kstrdup(d.redirect, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) if (!upperredirect)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886) goto out_put_upper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) if (d.redirect[0] == '/')
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888) poe = roe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) upperopaque = d.opaque;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) if (!d.stop && poe->numlower) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) stack = kcalloc(ofs->numlayer - 1, sizeof(struct ovl_path),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) if (!stack)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) goto out_put_upper;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) for (i = 0; !d.stop && i < poe->numlower; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) struct ovl_path lower = poe->lowerstack[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904) if (!ofs->config.redirect_follow)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) d.last = i == poe->numlower - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) d.last = lower.layer->idx == roe->numlower;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909) err = ovl_lookup_layer(lower.dentry, &d, &this, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) if (!this)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) if ((uppermetacopy || d.metacopy) && !ofs->config.metacopy) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) dput(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918) err = -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) pr_warn_ratelimited("refusing to follow metacopy origin for (%pd2)\n", dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) * If no origin fh is stored in upper of a merge dir, store fh
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) * of lower dir and set upper parent "impure".
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) if (upperdentry && !ctr && !ofs->noxattr && d.is_dir) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) err = ovl_fix_origin(ofs, dentry, this, upperdentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) dput(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) * When "verify_lower" feature is enabled, do not merge with a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937) * lower dir that does not match a stored origin xattr. In any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) * case, only verified origin is used for index lookup.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) * For non-dir dentry, if index=on, then ensure origin
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) * matches the dentry found using path based lookup,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) * otherwise error out.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) if (upperdentry && !ctr &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) ((d.is_dir && ovl_verify_lower(dentry->d_sb)) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) (!d.is_dir && ofs->config.index && origin_path))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) err = ovl_verify_origin(ofs, upperdentry, this, false);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) if (err) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) dput(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) if (d.is_dir)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) origin = this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) if (d.metacopy && ctr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) * Do not store intermediate metacopy dentries in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) * lower chain, except top most lower metacopy dentry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) * Continue the loop so that if there is an absolute
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) * redirect on this dentry, poe can be reset to roe.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) dput(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965) this = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) stack[ctr].dentry = this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968) stack[ctr].layer = lower.layer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) ctr++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) * Following redirects can have security consequences: it's like
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) * a symlink into the lower layer without the permission checks.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975) * This is only a problem if the upper layer is untrusted (e.g
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) * comes from an USB drive). This can allow a non-readable file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) * or directory to become readable.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) * Only following redirects when redirects are enabled disables
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) * this attack vector when not necessary.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982) err = -EPERM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) if (d.redirect && !ofs->config.redirect_follow) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) pr_warn_ratelimited("refusing to follow redirect for (%pd2)\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) if (d.stop)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) if (d.redirect && d.redirect[0] == '/' && poe != roe) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) poe = roe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) /* Find the current layer on the root dentry */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) i = lower.layer->idx - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) * For regular non-metacopy upper dentries, there is no lower
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) * path based lookup, hence ctr will be zero. If a dentry is found
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) * using ORIGIN xattr on upper, install it in stack.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) * For metacopy dentry, path based lookup will find lower dentries.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) * Just make sure a corresponding data dentry has been found.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) if (d.metacopy || (uppermetacopy && !ctr)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) } else if (!d.is_dir && upperdentry && !ctr && origin_path) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) if (WARN_ON(stack != NULL)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) err = -EIO;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) stack = origin_path;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) ctr = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) origin = origin_path->dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) origin_path = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) * Always lookup index if there is no-upperdentry.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) * For the case of upperdentry, we have set origin by now if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025) * needed to be set. There are basically three cases.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) * For directories, lookup index by lower inode and verify it matches
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) * upper inode. We only trust dir index if we verified that lower dir
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029) * matches origin, otherwise dir index entries may be inconsistent
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) * and we ignore them.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) * For regular upper, we already set origin if upper had ORIGIN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033) * xattr. There is no verification though as there is no path
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) * based dentry lookup in lower in this case.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) * For metacopy upper, we set a verified origin already if index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) * is enabled and if upper had an ORIGIN xattr.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) if (!upperdentry && ctr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) origin = stack[0].dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) if (origin && ovl_indexdir(dentry->d_sb) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) (!d.is_dir || ovl_index_all(dentry->d_sb))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) index = ovl_lookup_index(ofs, upperdentry, origin, true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) if (IS_ERR(index)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) err = PTR_ERR(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) index = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053) oe = ovl_alloc_entry(ctr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) err = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) if (!oe)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) goto out_put;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) memcpy(oe->lowerstack, stack, sizeof(struct ovl_path) * ctr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) dentry->d_fsdata = oe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) if (upperopaque)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) ovl_dentry_set_opaque(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) if (upperdentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) ovl_dentry_set_upper_alias(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066) else if (index) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) upperdentry = dget(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) upperredirect = ovl_get_redirect_xattr(ofs, upperdentry, 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) if (IS_ERR(upperredirect)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070) err = PTR_ERR(upperredirect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) upperredirect = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072) goto out_free_oe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) err = ovl_check_metacopy_xattr(ofs, upperdentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) if (err < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) goto out_free_oe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) uppermetacopy = err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) if (upperdentry || ctr) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) struct ovl_inode_params oip = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) .upperdentry = upperdentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) .lowerpath = stack,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084) .index = index,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) .numlower = ctr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) .redirect = upperredirect,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) .lowerdata = (ctr > 1 && !d.is_dir) ?
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088) stack[ctr - 1].dentry : NULL,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) inode = ovl_get_inode(dentry->d_sb, &oip);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) err = PTR_ERR(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) if (IS_ERR(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) goto out_free_oe;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) if (upperdentry && !uppermetacopy)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) ovl_set_flag(OVL_UPPERDATA, inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) ovl_dentry_update_reval(dentry, upperdentry,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) ovl_revert_creds(dentry->d_sb, old_cred);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103) if (origin_path) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) dput(origin_path->dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) kfree(origin_path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) dput(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) kfree(stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) kfree(d.redirect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110) return d_splice_alias(inode, dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) out_free_oe:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) dentry->d_fsdata = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) kfree(oe);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) out_put:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) dput(index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) for (i = 0; i < ctr; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) dput(stack[i].dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119) kfree(stack);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) out_put_upper:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121) if (origin_path) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) dput(origin_path->dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) kfree(origin_path);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) dput(upperdentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126) kfree(upperredirect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) kfree(d.redirect);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) ovl_revert_creds(dentry->d_sb, old_cred);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) return ERR_PTR(err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) bool ovl_lower_positive(struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) struct ovl_entry *poe = dentry->d_parent->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) const struct qstr *name = &dentry->d_name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) const struct cred *old_cred;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) unsigned int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) bool positive = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) bool done = false;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) * If dentry is negative, then lower is positive iff this is a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) * whiteout.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) if (!dentry->d_inode)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147) return ovl_dentry_is_opaque(dentry);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149) /* Negative upper -> positive lower */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) if (!ovl_dentry_upper(dentry))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) return true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) old_cred = ovl_override_creds(dentry->d_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) /* Positive upper -> have to look up lower to see whether it exists */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155) for (i = 0; !done && !positive && i < poe->numlower; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) struct dentry *this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) struct dentry *lowerdir = poe->lowerstack[i].dentry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) this = lookup_positive_unlocked(name->name, lowerdir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) name->len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) if (IS_ERR(this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) switch (PTR_ERR(this)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) case -ENOENT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164) case -ENAMETOOLONG:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) * Assume something is there, we just couldn't
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) * access it.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) positive = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176) positive = !ovl_is_whiteout(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) done = true;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) dput(this);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) ovl_revert_creds(dentry->d_sb, old_cred);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) return positive;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
3 Commits
0 Branches
0 Tags