/*
* if valid returns 1, otherwise 0.
*/
static int aufs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
int valid, err;
unsigned int sigen;
unsigned char do_udba;
struct super_block *sb;
struct inode *inode;
err = -EINVAL;
sb = dentry->d_sb;
inode = dentry->d_inode;
aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW);
sigen = au_sigen(sb);
if (au_digen(dentry) != sigen) {
AuDebugOn(IS_ROOT(dentry));
if (inode)
err = au_reval_dpath(dentry, sigen);
if (unlikely(err))
goto out_dgrade;
AuDebugOn(au_digen(dentry) != sigen);
}
if (inode && au_iigen(inode) != sigen) {
AuDebugOn(IS_ROOT(dentry));
err = au_refresh_hinode(inode, dentry);
if (unlikely(err))
goto out_dgrade;
AuDebugOn(au_iigen(inode) != sigen);
}
di_downgrade_lock(dentry, AuLock_IR);
AuDebugOn(au_digen(dentry) != sigen);
AuDebugOn(inode && au_iigen(inode) != sigen);
err = -EINVAL;
do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
if (do_udba && inode) {
aufs_bindex_t bstart = au_ibstart(inode);
if (bstart >= 0
&& au_test_higen(inode, au_h_iptr(inode, bstart)))
goto out;
}
err = h_d_revalidate(dentry, inode, nd, do_udba);
if (unlikely(!err && do_udba && au_dbstart(dentry) < 0))
/* both of real entry and whiteout found */
err = -EIO;
goto out;
out_dgrade:
di_downgrade_lock(dentry, AuLock_IR);
out:
aufs_read_unlock(dentry, AuLock_IR);
AuTraceErr(err);
valid = !err;
if (!valid)
AuDbg("%.*s invalid\n", AuDLNPair(dentry));
return valid;
}
/* common function to regular file and dir */
int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
int wlock)
{
int err;
unsigned int sigen, figen;
aufs_bindex_t bstart;
unsigned char pseudo_link;
struct dentry *dentry;
struct inode *inode;
err = 0;
dentry = file->f_dentry;
inode = dentry->d_inode;
AuDebugOn(au_special_file(inode->i_mode));
sigen = au_sigen(dentry->d_sb);
fi_write_lock(file);
figen = au_figen(file);
di_write_lock_child(dentry);
bstart = au_dbstart(dentry);
pseudo_link = (bstart != au_ibstart(inode));
if (sigen == figen && !pseudo_link && au_fbstart(file) == bstart) {
if (!wlock) {
di_downgrade_lock(dentry, AuLock_IR);
fi_downgrade_lock(file);
}
goto out; /* success */
}
AuDbg("sigen %d, figen %d\n", sigen, figen);
if (sigen != au_digen(dentry)
|| sigen != au_iigen(inode)) {
err = au_reval_dpath(dentry, sigen);
if (unlikely(err < 0))
goto out;
AuDebugOn(au_digen(dentry) != sigen
|| au_iigen(inode) != sigen);
}
err = refresh_file(file, reopen);
if (!err) {
if (!wlock) {
di_downgrade_lock(dentry, AuLock_IR);
fi_downgrade_lock(file);
}
} else {
di_write_unlock(dentry);
fi_write_unlock(file);
}
out:
return err;
}
/*
* if valid returns 1, otherwise 0.
*/
static int aufs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
{
int valid, err;
unsigned int sigen;
unsigned char do_udba;
struct super_block *sb;
struct inode *inode;
valid = 0;
if (unlikely(!au_di(dentry)))
goto out;
valid = 1;
sb = dentry->d_sb;
inode = dentry->d_inode;
/*
* todo: very ugly
* i_mutex of parent dir may be held,
* but we should not return 'invalid' due to busy.
*/
err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW | AuLock_NOPLM);
if (unlikely(err)) {
valid = err;
AuTraceErr(err);
goto out;
}
if (unlikely(au_dbrange_test(dentry))) {
err = -EINVAL;
AuTraceErr(err);
goto out_dgrade;
}
sigen = au_sigen(sb);
if (au_digen_test(dentry, sigen)) {
AuDebugOn(IS_ROOT(dentry));
err = au_reval_dpath(dentry, sigen);
if (unlikely(err)) {
AuTraceErr(err);
goto out_dgrade;
}
}
di_downgrade_lock(dentry, AuLock_IR);
err = -EINVAL;
if (inode && (IS_DEADDIR(inode) || !inode->i_nlink))
goto out_inval;
do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
if (do_udba && inode) {
aufs_bindex_t bstart = au_ibstart(inode);
struct inode *h_inode;
if (bstart >= 0) {
h_inode = au_h_iptr(inode, bstart);
if (h_inode && au_test_higen(inode, h_inode))
goto out_inval;
}
}
err = h_d_revalidate(dentry, inode, nd, do_udba);
if (unlikely(!err && do_udba && au_dbstart(dentry) < 0)) {
err = -EIO;
AuDbg("both of real entry and whiteout found, %.*s, err %d\n",
AuDLNPair(dentry), err);
}
goto out_inval;
out_dgrade:
di_downgrade_lock(dentry, AuLock_IR);
out_inval:
aufs_read_unlock(dentry, AuLock_IR);
AuTraceErr(err);
valid = !err;
out:
if (!valid) {
AuDbg("%.*s invalid, %d\n", AuDLNPair(dentry), valid);
d_drop(dentry);
}
return valid;
}
/*
* if valid returns 1, otherwise 0.
*/
static int aufs_d_revalidate(struct dentry *dentry, unsigned int flags)
{
int valid, err;
unsigned int sigen;
unsigned char do_udba;
struct super_block *sb;
struct inode *inode;
/* todo: support rcu-walk? */
if (flags & LOOKUP_RCU)
return -ECHILD;
valid = 0;
if (unlikely(!au_di(dentry)))
goto out;
valid = 1;
sb = dentry->d_sb;
/*
* todo: very ugly
* i_mutex of parent dir may be held,
* but we should not return 'invalid' due to busy.
*/
err = aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW | AuLock_NOPLM);
if (unlikely(err)) {
valid = err;
AuTraceErr(err);
goto out;
}
inode = NULL;
if (d_really_is_positive(dentry))
inode = d_inode(dentry);
if (unlikely(inode && is_bad_inode(inode))) {
err = -EINVAL;
AuTraceErr(err);
goto out_dgrade;
}
if (unlikely(au_dbrange_test(dentry))) {
err = -EINVAL;
AuTraceErr(err);
goto out_dgrade;
}
sigen = au_sigen(sb);
if (au_digen_test(dentry, sigen)) {
AuDebugOn(IS_ROOT(dentry));
err = au_reval_dpath(dentry, sigen);
if (unlikely(err)) {
AuTraceErr(err);
goto out_dgrade;
}
}
di_downgrade_lock(dentry, AuLock_IR);
err = -EINVAL;
if (!(flags & (LOOKUP_OPEN | LOOKUP_EMPTY))
&& inode
&& !(inode->i_state && I_LINKABLE)
&& (IS_DEADDIR(inode) || !inode->i_nlink))
goto out_inval;
do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
if (do_udba && inode) {
aufs_bindex_t bstart = au_ibstart(inode);
struct inode *h_inode;
if (bstart >= 0) {
h_inode = au_h_iptr(inode, bstart);
if (h_inode && au_test_higen(inode, h_inode))
goto out_inval;
}
}
err = h_d_revalidate(dentry, inode, flags, do_udba);
if (unlikely(!err && do_udba && au_dbstart(dentry) < 0)) {
err = -EIO;
AuDbg("both of real entry and whiteout found, %p, err %d\n",
dentry, err);
}
goto out_inval;
out_dgrade:
di_downgrade_lock(dentry, AuLock_IR);
out_inval:
aufs_read_unlock(dentry, AuLock_IR);
AuTraceErr(err);
valid = !err;
out:
if (!valid) {
AuDbg("%pd invalid, %d\n", dentry, valid);
d_drop(dentry);
}
return valid;
}
/*
* test if the branch is deletable or not.
*/
static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
unsigned int sigen, const unsigned int verbose)
{
int err, i, j, ndentry;
aufs_bindex_t bstart, bend;
struct au_dcsub_pages dpages;
struct au_dpage *dpage;
struct dentry *d;
err = au_dpages_init(&dpages, GFP_NOFS);
if (unlikely(err))
goto out;
err = au_dcsub_pages(&dpages, root, NULL, NULL);
if (unlikely(err))
goto out_dpages;
for (i = 0; !err && i < dpages.ndpage; i++) {
dpage = dpages.dpages + i;
ndentry = dpage->ndentry;
for (j = 0; !err && j < ndentry; j++) {
d = dpage->dentries[j];
AuDebugOn(!atomic_read(&d->d_count));
if (!au_digen_test(d, sigen)) {
di_read_lock_child(d, AuLock_IR);
if (unlikely(au_dbrange_test(d))) {
di_read_unlock(d, AuLock_IR);
continue;
}
} else {
di_write_lock_child(d);
if (unlikely(au_dbrange_test(d))) {
di_write_unlock(d);
continue;
}
err = au_reval_dpath(d, sigen);
if (!err)
di_downgrade_lock(d, AuLock_IR);
else {
di_write_unlock(d);
break;
}
}
/* AuDbgDentry(d); */
bstart = au_dbstart(d);
bend = au_dbend(d);
if (bstart <= bindex
&& bindex <= bend
&& au_h_dptr(d, bindex)
&& au_test_dbusy(d, bstart, bend)) {
err = -EBUSY;
AuVerbose(verbose, "busy %.*s\n", AuDLNPair(d));
AuDbgDentry(d);
}
di_read_unlock(d, AuLock_IR);
}
}
out_dpages:
au_dpages_free(&dpages);
out:
return err;
}
