blob: b3c61267c8b5fc32398ec347b65ea0dbb4da9c0f [file] [log] [blame]
/*
*
* 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/slab.h>
#include <linux/cred.h>
#include <linux/xattr.h>
#include <linux/posix_acl.h>
#include <linux/ratelimit.h>
#include "overlayfs.h"
int ovl_setattr(struct dentry *dentry, struct iattr *attr)
{
int err;
bool full_copy_up = false;
struct dentry *upperdentry;
const struct cred *old_cred;
err = setattr_prepare(dentry, attr);
if (err)
return err;
err = ovl_want_write(dentry);
if (err)
goto out;
if (attr->ia_valid & ATTR_SIZE) {
struct inode *realinode = d_inode(ovl_dentry_real(dentry));
err = -ETXTBSY;
if (atomic_read(&realinode->i_writecount) < 0)
goto out_drop_write;
/* Truncate should trigger data copy up as well */
full_copy_up = true;
}
if (!full_copy_up)
err = ovl_copy_up(dentry);
else
err = ovl_copy_up_with_data(dentry);
if (!err) {
struct inode *winode = NULL;
upperdentry = ovl_dentry_upper(dentry);
if (attr->ia_valid & ATTR_SIZE) {
winode = d_inode(upperdentry);
err = get_write_access(winode);
if (err)
goto out_drop_write;
}
if (attr->ia_valid & (ATTR_KILL_SUID|ATTR_KILL_SGID))
attr->ia_valid &= ~ATTR_MODE;
inode_lock(upperdentry->d_inode);
old_cred = ovl_override_creds(dentry->d_sb);
err = notify_change(upperdentry, attr, NULL);
ovl_revert_creds(old_cred);
if (!err)
ovl_copyattr(upperdentry->d_inode, dentry->d_inode);
inode_unlock(upperdentry->d_inode);
if (winode)
put_write_access(winode);
}
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat,
struct ovl_layer *lower_layer)
{
bool samefs = ovl_same_sb(dentry->d_sb);
unsigned int xinobits = ovl_xino_bits(dentry->d_sb);
if (samefs) {
/*
* When all layers are on the same fs, all real inode
* number are unique, so we use the overlay st_dev,
* which is friendly to du -x.
*/
stat->dev = dentry->d_sb->s_dev;
return 0;
} else if (xinobits) {
unsigned int shift = 64 - xinobits;
/*
* All inode numbers of underlying fs should not be using the
* high xinobits, so we use high xinobits to partition the
* overlay st_ino address space. The high bits holds the fsid
* (upper fsid is 0). This way overlay inode numbers are unique
* and all inodes use overlay st_dev. Inode numbers are also
* persistent for a given layer configuration.
*/
if (stat->ino >> shift) {
pr_warn_ratelimited("overlayfs: inode number too big (%pd2, ino=%llu, xinobits=%d)\n",
dentry, stat->ino, xinobits);
} else {
if (lower_layer)
stat->ino |= ((u64)lower_layer->fsid) << shift;
stat->dev = dentry->d_sb->s_dev;
return 0;
}
}
/* The inode could not be mapped to a unified st_ino address space */
if (S_ISDIR(dentry->d_inode->i_mode)) {
/*
* Always use the overlay st_dev for directories, so 'find
* -xdev' will scan the entire overlay mount and won't cross the
* overlay mount boundaries.
*
* If not all layers are on the same fs the pair {real st_ino;
* overlay st_dev} is not unique, so use the non persistent
* overlay st_ino for directories.
*/
stat->dev = dentry->d_sb->s_dev;
stat->ino = dentry->d_inode->i_ino;
} else if (lower_layer && lower_layer->fsid) {
/*
* For non-samefs setup, if we cannot map all layers st_ino
* to a unified address space, we need to make sure that st_dev
* is unique per lower fs. Upper layer uses real st_dev and
* lower layers use the unique anonymous bdev assigned to the
* lower fs.
*/
stat->dev = lower_layer->fs->pseudo_dev;
}
return 0;
}
int ovl_getattr(const struct path *path, struct kstat *stat,
u32 request_mask, unsigned int flags)
{
struct dentry *dentry = path->dentry;
enum ovl_path_type type;
struct path realpath;
const struct cred *old_cred;
bool is_dir = S_ISDIR(dentry->d_inode->i_mode);
bool samefs = ovl_same_sb(dentry->d_sb);
struct ovl_layer *lower_layer = NULL;
int err;
bool metacopy_blocks = false;
metacopy_blocks = ovl_is_metacopy_dentry(dentry);
type = ovl_path_real(dentry, &realpath);
old_cred = ovl_override_creds(dentry->d_sb);
err = vfs_getattr(&realpath, stat, request_mask, flags);
if (err)
goto out;
/*
* For non-dir or same fs, we use st_ino of the copy up origin.
* This guaranties constant st_dev/st_ino across copy up.
* With xino feature and non-samefs, we use st_ino of the copy up
* origin masked with high bits that represent the layer id.
*
* If lower filesystem supports NFS file handles, this also guaranties
* persistent st_ino across mount cycle.
*/
if (!is_dir || samefs || ovl_xino_bits(dentry->d_sb)) {
if (!OVL_TYPE_UPPER(type)) {
lower_layer = ovl_layer_lower(dentry);
} else if (OVL_TYPE_ORIGIN(type)) {
struct kstat lowerstat;
u32 lowermask = STATX_INO | STATX_BLOCKS |
(!is_dir ? STATX_NLINK : 0);
ovl_path_lower(dentry, &realpath);
err = vfs_getattr(&realpath, &lowerstat,
lowermask, flags);
if (err)
goto out;
/*
* Lower hardlinks may be broken on copy up to different
* upper files, so we cannot use the lower origin st_ino
* for those different files, even for the same fs case.
*
* Similarly, several redirected dirs can point to the
* same dir on a lower layer. With the "verify_lower"
* feature, we do not use the lower origin st_ino, if
* we haven't verified that this redirect is unique.
*
* With inodes index enabled, it is safe to use st_ino
* of an indexed origin. The index validates that the
* upper hardlink is not broken and that a redirected
* dir is the only redirect to that origin.
*/
if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) ||
(!ovl_verify_lower(dentry->d_sb) &&
(is_dir || lowerstat.nlink == 1))) {
stat->ino = lowerstat.ino;
lower_layer = ovl_layer_lower(dentry);
}
/*
* If we are querying a metacopy dentry and lower
* dentry is data dentry, then use the blocks we
* queried just now. We don't have to do additional
* vfs_getattr(). If lower itself is metacopy, then
* additional vfs_getattr() is unavoidable.
*/
if (metacopy_blocks &&
realpath.dentry == ovl_dentry_lowerdata(dentry)) {
stat->blocks = lowerstat.blocks;
metacopy_blocks = false;
}
}
if (metacopy_blocks) {
/*
* If lower is not same as lowerdata or if there was
* no origin on upper, we can end up here.
*/
struct kstat lowerdatastat;
u32 lowermask = STATX_BLOCKS;
ovl_path_lowerdata(dentry, &realpath);
err = vfs_getattr(&realpath, &lowerdatastat,
lowermask, flags);
if (err)
goto out;
stat->blocks = lowerdatastat.blocks;
}
}
err = ovl_map_dev_ino(dentry, stat, lower_layer);
if (err)
goto out;
/*
* 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 (is_dir && OVL_TYPE_MERGE(type))
stat->nlink = 1;
/*
* Return the overlay inode nlinks for indexed upper inodes.
* Overlay inode nlink counts the union of the upper hardlinks
* and non-covered lower hardlinks. It does not include the upper
* index hardlink.
*/
if (!is_dir && ovl_test_flag(OVL_INDEX, d_inode(dentry)))
stat->nlink = dentry->d_inode->i_nlink;
out:
ovl_revert_creds(old_cred);
return err;
}
int ovl_permission(struct inode *inode, int mask)
{
struct inode *upperinode = ovl_inode_upper(inode);
struct inode *realinode = upperinode ?: ovl_inode_lower(inode);
const struct cred *old_cred;
int err;
/* Careful in RCU walk mode */
if (!realinode) {
WARN_ON(!(mask & MAY_NOT_BLOCK));
return -ECHILD;
}
/*
* Check overlay inode with the creds of task and underlying inode
* with creds of mounter
*/
err = generic_permission(inode, mask);
if (err)
return err;
old_cred = ovl_override_creds(inode->i_sb);
if (!upperinode &&
!special_file(realinode->i_mode) && mask & MAY_WRITE) {
mask &= ~(MAY_WRITE | MAY_APPEND);
/* Make sure mounter can read file for copy up later */
mask |= MAY_READ;
}
err = inode_permission(realinode, mask);
ovl_revert_creds(old_cred);
return err;
}
static const char *ovl_get_link(struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
const struct cred *old_cred;
const char *p;
if (!dentry)
return ERR_PTR(-ECHILD);
old_cred = ovl_override_creds(dentry->d_sb);
p = vfs_get_link(ovl_dentry_real(dentry), done);
ovl_revert_creds(old_cred);
return p;
}
bool ovl_is_private_xattr(const char *name)
{
return strncmp(name, OVL_XATTR_PREFIX,
sizeof(OVL_XATTR_PREFIX) - 1) == 0;
}
int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
const void *value, size_t size, int flags)
{
int err;
struct dentry *upperdentry = ovl_i_dentry_upper(inode);
struct dentry *realdentry = upperdentry ?: ovl_dentry_lower(dentry);
const struct cred *old_cred;
err = ovl_want_write(dentry);
if (err)
goto out;
if (!value && !upperdentry) {
err = vfs_getxattr(realdentry, name, NULL, 0);
if (err < 0)
goto out_drop_write;
}
if (!upperdentry) {
err = ovl_copy_up(dentry);
if (err)
goto out_drop_write;
realdentry = ovl_dentry_upper(dentry);
}
old_cred = ovl_override_creds(dentry->d_sb);
if (value)
err = vfs_setxattr(realdentry, name, value, size, flags);
else {
WARN_ON(flags != XATTR_REPLACE);
err = vfs_removexattr(realdentry, name);
}
ovl_revert_creds(old_cred);
/* copy c/mtime */
ovl_copyattr(d_inode(realdentry), inode);
out_drop_write:
ovl_drop_write(dentry);
out:
return err;
}
int ovl_xattr_get(struct dentry *dentry, struct inode *inode, const char *name,
void *value, size_t size)
{
ssize_t res;
const struct cred *old_cred;
struct dentry *realdentry =
ovl_i_dentry_upper(inode) ?: ovl_dentry_lower(dentry);
old_cred = ovl_override_creds(dentry->d_sb);
res = vfs_getxattr(realdentry, name, value, size);
ovl_revert_creds(old_cred);
return res;
}
static bool ovl_can_list(const char *s)
{
/* List all non-trusted xatts */
if (strncmp(s, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) != 0)
return true;
/* Never list trusted.overlay, list other trusted for superuser only */
return !ovl_is_private_xattr(s) && capable(CAP_SYS_ADMIN);
}
ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size)
{
struct dentry *realdentry = ovl_dentry_real(dentry);
ssize_t res;
size_t len;
char *s;
const struct cred *old_cred;
old_cred = ovl_override_creds(dentry->d_sb);
res = vfs_listxattr(realdentry, list, size);
ovl_revert_creds(old_cred);
if (res <= 0 || size == 0)
return res;
/* filter out private xattrs */
for (s = list, len = res; len;) {
size_t slen = strnlen(s, len) + 1;
/* underlying fs providing us with an broken xattr list? */
if (WARN_ON(slen > len))
return -EIO;
len -= slen;
if (!ovl_can_list(s)) {
res -= slen;
memmove(s, s + slen, len);
} else {
s += slen;
}
}
return res;
}
struct posix_acl *ovl_get_acl(struct inode *inode, int type)
{
struct inode *realinode = ovl_inode_real(inode);
const struct cred *old_cred;
struct posix_acl *acl;
if (!IS_ENABLED(CONFIG_FS_POSIX_ACL) || !IS_POSIXACL(realinode))
return NULL;
old_cred = ovl_override_creds(inode->i_sb);
acl = get_acl(realinode, type);
ovl_revert_creds(old_cred);
return acl;
}
int ovl_update_time(struct inode *inode, struct timespec64 *ts, int flags)
{
if (flags & S_ATIME) {
struct ovl_fs *ofs = inode->i_sb->s_fs_info;
struct path upperpath = {
.mnt = ofs->upper_mnt,
.dentry = ovl_upperdentry_dereference(OVL_I(inode)),
};
if (upperpath.dentry) {
touch_atime(&upperpath);
inode->i_atime = d_inode(upperpath.dentry)->i_atime;
}
}
return 0;
}
static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len)
{
int err;
struct inode *realinode = ovl_inode_real(inode);
const struct cred *old_cred;
if (!realinode->i_op->fiemap)
return -EOPNOTSUPP;
old_cred = ovl_override_creds(inode->i_sb);
if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
filemap_write_and_wait(realinode->i_mapping);
err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
ovl_revert_creds(old_cred);
return err;
}
static const struct inode_operations ovl_file_inode_operations = {
.setattr = ovl_setattr,
.permission = ovl_permission,
.getattr = ovl_getattr,
.listxattr = ovl_listxattr,
.get_acl = ovl_get_acl,
.update_time = ovl_update_time,
.fiemap = ovl_fiemap,
};
static const struct inode_operations ovl_symlink_inode_operations = {
.setattr = ovl_setattr,
.get_link = ovl_get_link,
.getattr = ovl_getattr,
.listxattr = ovl_listxattr,
.update_time = ovl_update_time,
};
static const struct inode_operations ovl_special_inode_operations = {
.setattr = ovl_setattr,
.permission = ovl_permission,
.getattr = ovl_getattr,
.listxattr = ovl_listxattr,
.get_acl = ovl_get_acl,
.update_time = ovl_update_time,
};
static const struct address_space_operations ovl_aops = {
/* For O_DIRECT dentry_open() checks f_mapping->a_ops->direct_IO */
.direct_IO = noop_direct_IO,
};
/*
* It is possible to stack overlayfs instance on top of another
* overlayfs instance as lower layer. We need to annonate the
* stackable i_mutex locks according to stack level of the super
* block instance. An overlayfs instance can never be in stack
* depth 0 (there is always a real fs below it). An overlayfs
* inode lock will use the lockdep annotaion ovl_i_mutex_key[depth].
*
* For example, here is a snip from /proc/lockdep_chains after
* dir_iterate of nested overlayfs:
*
* [...] &ovl_i_mutex_dir_key[depth] (stack_depth=2)
* [...] &ovl_i_mutex_dir_key[depth]#2 (stack_depth=1)
* [...] &type->i_mutex_dir_key (stack_depth=0)
*/
#define OVL_MAX_NESTING FILESYSTEM_MAX_STACK_DEPTH
static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode)
{
#ifdef CONFIG_LOCKDEP
static struct lock_class_key ovl_i_mutex_key[OVL_MAX_NESTING];
static struct lock_class_key ovl_i_mutex_dir_key[OVL_MAX_NESTING];
static struct lock_class_key ovl_i_lock_key[OVL_MAX_NESTING];
int depth = inode->i_sb->s_stack_depth - 1;
if (WARN_ON_ONCE(depth < 0 || depth >= OVL_MAX_NESTING))
depth = 0;
if (S_ISDIR(inode->i_mode))
lockdep_set_class(&inode->i_rwsem, &ovl_i_mutex_dir_key[depth]);
else
lockdep_set_class(&inode->i_rwsem, &ovl_i_mutex_key[depth]);
lockdep_set_class(&OVL_I(inode)->lock, &ovl_i_lock_key[depth]);
#endif
}
static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev,
unsigned long ino, int fsid)
{
int xinobits = ovl_xino_bits(inode->i_sb);
/*
* When NFS export is enabled and d_ino is consistent with st_ino
* (samefs or i_ino has enough bits to encode layer), set the same
* value used for d_ino to i_ino, because nfsd readdirplus compares
* d_ino values to i_ino values of child entries. When called from
* ovl_new_inode(), ino arg is 0, so i_ino will be updated to real
* upper inode i_ino on ovl_inode_init() or ovl_inode_update().
*/
if (inode->i_sb->s_export_op &&
(ovl_same_sb(inode->i_sb) || xinobits)) {
inode->i_ino = ino;
if (xinobits && fsid && !(ino >> (64 - xinobits)))
inode->i_ino |= (unsigned long)fsid << (64 - xinobits);
} else {
inode->i_ino = get_next_ino();
}
inode->i_mode = mode;
inode->i_flags |= S_NOCMTIME;
#ifdef CONFIG_FS_POSIX_ACL
inode->i_acl = inode->i_default_acl = ACL_DONT_CACHE;
#endif
ovl_lockdep_annotate_inode_mutex_key(inode);
switch (mode & S_IFMT) {
case S_IFREG:
inode->i_op = &ovl_file_inode_operations;
inode->i_fop = &ovl_file_operations;
inode->i_mapping->a_ops = &ovl_aops;
break;
case S_IFDIR:
inode->i_op = &ovl_dir_inode_operations;
inode->i_fop = &ovl_dir_operations;
break;
case S_IFLNK:
inode->i_op = &ovl_symlink_inode_operations;
break;
default:
inode->i_op = &ovl_special_inode_operations;
init_special_inode(inode, mode, rdev);
break;
}
}
/*
* With inodes index enabled, an overlay inode nlink counts the union of upper
* hardlinks and non-covered lower hardlinks. During the lifetime of a non-pure
* upper inode, the following nlink modifying operations can happen:
*
* 1. Lower hardlink copy up
* 2. Upper hardlink created, unlinked or renamed over
* 3. Lower hardlink whiteout or renamed over
*
* For the first, copy up case, the union nlink does not change, whether the
* operation succeeds or fails, but the upper inode nlink may change.
* Therefore, before copy up, we store the union nlink value relative to the
* lower inode nlink in the index inode xattr trusted.overlay.nlink.
*
* For the second, upper hardlink case, the union nlink should be incremented
* or decremented IFF the operation succeeds, aligned with nlink change of the
* upper inode. Therefore, before link/unlink/rename, we store the union nlink
* value relative to the upper inode nlink in the index inode.
*
* For the last, lower cover up case, we simplify things by preceding the
* whiteout or cover up with copy up. This makes sure that there is an index
* upper inode where the nlink xattr can be stored before the copied up upper
* entry is unlink.
*/
#define OVL_NLINK_ADD_UPPER (1 << 0)
/*
* On-disk format for indexed nlink:
*
* nlink relative to the upper inode - "U[+-]NUM"
* nlink relative to the lower inode - "L[+-]NUM"
*/
static int ovl_set_nlink_common(struct dentry *dentry,
struct dentry *realdentry, const char *format)
{
struct inode *inode = d_inode(dentry);
struct inode *realinode = d_inode(realdentry);
char buf[13];
int len;
len = snprintf(buf, sizeof(buf), format,
(int) (inode->i_nlink - realinode->i_nlink));
if (WARN_ON(len >= sizeof(buf)))
return -EIO;
return ovl_do_setxattr(ovl_dentry_upper(dentry),
OVL_XATTR_NLINK, buf, len, 0);
}
int ovl_set_nlink_upper(struct dentry *dentry)
{
return ovl_set_nlink_common(dentry, ovl_dentry_upper(dentry), "U%+i");
}
int ovl_set_nlink_lower(struct dentry *dentry)
{
return ovl_set_nlink_common(dentry, ovl_dentry_lower(dentry), "L%+i");
}
unsigned int ovl_get_nlink(struct dentry *lowerdentry,
struct dentry *upperdentry,
unsigned int fallback)
{
int nlink_diff;
int nlink;
char buf[13];
int err;
if (!lowerdentry || !upperdentry || d_inode(lowerdentry)->i_nlink == 1)
return fallback;
err = vfs_getxattr(upperdentry, OVL_XATTR_NLINK, &buf, sizeof(buf) - 1);
if (err < 0)
goto fail;
buf[err] = '\0';
if ((buf[0] != 'L' && buf[0] != 'U') ||
(buf[1] != '+' && buf[1] != '-'))
goto fail;
err = kstrtoint(buf + 1, 10, &nlink_diff);
if (err < 0)
goto fail;
nlink = d_inode(buf[0] == 'L' ? lowerdentry : upperdentry)->i_nlink;
nlink += nlink_diff;
if (nlink <= 0)
goto fail;
return nlink;
fail:
pr_warn_ratelimited("overlayfs: failed to get index nlink (%pd2, err=%i)\n",
upperdentry, err);
return fallback;
}
struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev)
{
struct inode *inode;
inode = new_inode(sb);
if (inode)
ovl_fill_inode(inode, mode, rdev, 0, 0);
return inode;
}
static int ovl_inode_test(struct inode *inode, void *data)
{
return inode->i_private == data;
}
static int ovl_inode_set(struct inode *inode, void *data)
{
inode->i_private = data;
return 0;
}
static bool ovl_verify_inode(struct inode *inode, struct dentry *lowerdentry,
struct dentry *upperdentry, bool strict)
{
/*
* For directories, @strict verify from lookup path performs consistency
* checks, so NULL lower/upper in dentry must match NULL lower/upper in
* inode. Non @strict verify from NFS handle decode path passes NULL for
* 'unknown' lower/upper.
*/
if (S_ISDIR(inode->i_mode) && strict) {
/* Real lower dir moved to upper layer under us? */
if (!lowerdentry && ovl_inode_lower(inode))
return false;
/* Lookup of an uncovered redirect origin? */
if (!upperdentry && ovl_inode_upper(inode))
return false;
}
/*
* Allow non-NULL lower inode in ovl_inode even if lowerdentry is NULL.
* This happens when finding a copied up overlay inode for a renamed
* or hardlinked overlay dentry and lower dentry cannot be followed
* by origin because lower fs does not support file handles.
*/
if (lowerdentry && ovl_inode_lower(inode) != d_inode(lowerdentry))
return false;
/*
* Allow non-NULL __upperdentry in inode even if upperdentry is NULL.
* This happens when finding a lower alias for a copied up hard link.
*/
if (upperdentry && ovl_inode_upper(inode) != d_inode(upperdentry))
return false;
return true;
}
struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
bool is_upper)
{
struct inode *inode, *key = d_inode(real);
inode = ilookup5(sb, (unsigned long) key, ovl_inode_test, key);
if (!inode)
return NULL;
if (!ovl_verify_inode(inode, is_upper ? NULL : real,
is_upper ? real : NULL, false)) {
iput(inode);
return ERR_PTR(-ESTALE);
}
return inode;
}
/*
* Does overlay inode need to be hashed by lower inode?
*/
static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper,
struct dentry *lower, struct dentry *index)
{
struct ovl_fs *ofs = sb->s_fs_info;
/* No, if pure upper */
if (!lower)
return false;
/* Yes, if already indexed */
if (index)
return true;
/* Yes, if won't be copied up */
if (!ofs->upper_mnt)
return true;
/* No, if lower hardlink is or will be broken on copy up */
if ((upper || !ovl_indexdir(sb)) &&
!d_is_dir(lower) && d_inode(lower)->i_nlink > 1)
return false;
/* No, if non-indexed upper with NFS export */
if (sb->s_export_op && upper)
return false;
/* Otherwise, hash by lower inode for fsnotify */
return true;
}
static struct inode *ovl_iget5(struct super_block *sb, struct inode *newinode,
struct inode *key)
{
return newinode ? inode_insert5(newinode, (unsigned long) key,
ovl_inode_test, ovl_inode_set, key) :
iget5_locked(sb, (unsigned long) key,
ovl_inode_test, ovl_inode_set, key);
}
struct inode *ovl_get_inode(struct super_block *sb,
struct ovl_inode_params *oip)
{
struct dentry *upperdentry = oip->upperdentry;
struct ovl_path *lowerpath = oip->lowerpath;
struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
struct inode *inode;
struct dentry *lowerdentry = lowerpath ? lowerpath->dentry : NULL;
bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry,
oip->index);
int fsid = bylower ? oip->lowerpath->layer->fsid : 0;
bool is_dir, metacopy = false;
unsigned long ino = 0;
int err = -ENOMEM;
if (!realinode)
realinode = d_inode(lowerdentry);
/*
* Copy up origin (lower) may exist for non-indexed upper, but we must
* not use lower as hash key if this is a broken hardlink.
*/
is_dir = S_ISDIR(realinode->i_mode);
if (upperdentry || bylower) {
struct inode *key = d_inode(bylower ? lowerdentry :
upperdentry);
unsigned int nlink = is_dir ? 1 : realinode->i_nlink;
inode = ovl_iget5(sb, oip->newinode, key);
if (!inode)
goto out_err;
if (!(inode->i_state & I_NEW)) {
/*
* Verify that the underlying files stored in the inode
* match those in the dentry.
*/
if (!ovl_verify_inode(inode, lowerdentry, upperdentry,
true)) {
iput(inode);
err = -ESTALE;
goto out_err;
}
dput(upperdentry);
kfree(oip->redirect);
goto out;
}
/* Recalculate nlink for non-dir due to indexing */
if (!is_dir)
nlink = ovl_get_nlink(lowerdentry, upperdentry, nlink);
set_nlink(inode, nlink);
ino = key->i_ino;
} else {
/* Lower hardlink that will be broken on copy up */
inode = new_inode(sb);
if (!inode) {
err = -ENOMEM;
goto out_err;
}
}
ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
ovl_inode_init(inode, upperdentry, lowerdentry, oip->lowerdata);
if (upperdentry && ovl_is_impuredir(upperdentry))
ovl_set_flag(OVL_IMPURE, inode);
if (oip->index)
ovl_set_flag(OVL_INDEX, inode);
if (upperdentry) {
err = ovl_check_metacopy_xattr(upperdentry);
if (err < 0)
goto out_err;
metacopy = err;
if (!metacopy)
ovl_set_flag(OVL_UPPERDATA, inode);
}
OVL_I(inode)->redirect = oip->redirect;
if (bylower)
ovl_set_flag(OVL_CONST_INO, inode);
/* Check for non-merge dir that may have whiteouts */
if (is_dir) {
if (((upperdentry && lowerdentry) || oip->numlower > 1) ||
ovl_check_origin_xattr(upperdentry ?: lowerdentry)) {
ovl_set_flag(OVL_WHITEOUTS, inode);
}
}
if (inode->i_state & I_NEW)
unlock_new_inode(inode);
out:
return inode;
out_err:
inode = ERR_PTR(err);
goto out;
}