void di_read_unlock(struct dentry *d, int flags)
{
if (d->d_inode) {
if (au_ftest_lock(flags, IW)) {
au_dbg_verify_dinode(d);
ii_write_unlock(d->d_inode);
} else if (au_ftest_lock(flags, IR)) {
au_dbg_verify_dinode(d);
ii_read_unlock(d->d_inode);
}
}
au_rw_read_unlock(&au_di(d)->di_rwsem);
}
void di_write_unlock(struct dentry *d)
{
au_dbg_verify_dinode(d);
if (d->d_inode)
ii_write_unlock(d->d_inode);
au_rw_write_unlock(&au_di(d)->di_rwsem);
}
int au_refresh_dentry(struct dentry *dentry, struct dentry *parent)
{
int err, ebrange;
unsigned int sigen;
struct au_dinfo *dinfo, *tmp;
struct super_block *sb;
struct inode *inode;
DiMustWriteLock(dentry);
AuDebugOn(IS_ROOT(dentry));
AuDebugOn(!parent->d_inode);
sb = dentry->d_sb;
inode = dentry->d_inode;
sigen = au_sigen(sb);
err = au_digen_test(parent, sigen);
if (unlikely(err))
goto out;
dinfo = au_di(dentry);
err = au_di_realloc(dinfo, au_sbend(sb) + 1);
if (unlikely(err))
goto out;
ebrange = au_dbrange_test(dentry);
if (!ebrange)
ebrange = au_do_refresh_hdentry(dentry, parent);
if (d_unhashed(dentry) || ebrange) {
AuDebugOn(au_dbstart(dentry) < 0 && au_dbend(dentry) >= 0);
if (inode)
err = au_refresh_hinode_self(inode);
au_dbg_verify_dinode(dentry);
if (!err)
goto out_dgen; /* success */
goto out;
}
/* temporary dinfo */
AuDbgDentry(dentry);
err = -ENOMEM;
tmp = au_di_alloc(sb, AuLsc_DI_TMP);
if (unlikely(!tmp))
goto out;
au_di_swap(tmp, dinfo);
/* returns the number of positive dentries */
/*
* if current working dir is removed, it returns an error.
* but the dentry is legal.
*/
err = au_lkup_dentry(dentry, /*bstart*/0, /*type*/0, /*nd*/NULL);
AuDbgDentry(dentry);
au_di_swap(tmp, dinfo);
if (err == -ENOENT)
err = 0;
if (err >= 0) {
/* compare/refresh by dinfo */
AuDbgDentry(dentry);
err = au_refresh_by_dinfo(dentry, dinfo, tmp);
au_dbg_verify_dinode(dentry);
AuTraceErr(err);
}
au_rw_write_unlock(&tmp->di_rwsem);
au_di_free(tmp);
if (unlikely(err))
goto out;
out_dgen:
au_update_digen(dentry);
out:
if (unlikely(err && !(dentry->d_flags & DCACHE_NFSFS_RENAMED))) {
AuIOErr("failed refreshing %.*s, %d\n",
AuDLNPair(dentry), err);
AuDbgDentry(dentry);
}
AuTraceErr(err);
return err;
}
/*
* By adding a dirty branch, a cached dentry may be affected in various ways.
*
* a dirty branch is added
* - on the top of layers
* - in the middle of layers
* - to the bottom of layers
*
* on the added branch there exists
* - a whiteout
* - a diropq
* - a same named entry
* + exist
* * negative --> positive
* * positive --> positive
* - type is unchanged
* - type is changed
* + doesn't exist
* * negative --> negative
* * positive --> negative (rejected by au_br_del() for non-dir case)
* - none
*/
static int au_refresh_by_dinfo(struct dentry *dentry, struct au_dinfo *dinfo,
struct au_dinfo *tmp)
{
int err;
aufs_bindex_t bindex, bend;
struct {
struct dentry *dentry;
struct inode *inode;
mode_t mode;
} orig_h, tmp_h;
struct au_hdentry *hd;
struct inode *inode, *h_inode;
struct dentry *h_dentry;
err = 0;
AuDebugOn(dinfo->di_bstart < 0);
orig_h.dentry = dinfo->di_hdentry[dinfo->di_bstart].hd_dentry;
orig_h.inode = orig_h.dentry->d_inode;
orig_h.mode = 0;
if (orig_h.inode)
orig_h.mode = orig_h.inode->i_mode & S_IFMT;
memset(&tmp_h, 0, sizeof(tmp_h));
if (tmp->di_bstart >= 0) {
tmp_h.dentry = tmp->di_hdentry[tmp->di_bstart].hd_dentry;
tmp_h.inode = tmp_h.dentry->d_inode;
if (tmp_h.inode)
tmp_h.mode = tmp_h.inode->i_mode & S_IFMT;
}
inode = dentry->d_inode;
if (!orig_h.inode) {
AuDbg("nagative originally\n");
if (inode) {
au_hide(dentry);
goto out;
}
AuDebugOn(inode);
AuDebugOn(dinfo->di_bstart != dinfo->di_bend);
AuDebugOn(dinfo->di_bdiropq != -1);
if (!tmp_h.inode) {
AuDbg("negative --> negative\n");
/* should have only one negative lower */
if (tmp->di_bstart >= 0
&& tmp->di_bstart < dinfo->di_bstart) {
AuDebugOn(tmp->di_bstart != tmp->di_bend);
AuDebugOn(dinfo->di_bstart != dinfo->di_bend);
au_set_h_dptr(dentry, dinfo->di_bstart, NULL);
au_di_cp(dinfo, tmp);
hd = tmp->di_hdentry + tmp->di_bstart;
au_set_h_dptr(dentry, tmp->di_bstart,
dget(hd->hd_dentry));
}
au_dbg_verify_dinode(dentry);
} else {
AuDbg("negative --> positive\n");
/*
* similar to the behaviour of creating with bypassing
* aufs.
* unhash it in order to force an error in the
* succeeding create operation.
* we should not set S_DEAD here.
*/
d_drop(dentry);
/* au_di_swap(tmp, dinfo); */
au_dbg_verify_dinode(dentry);
}
} else {
AuDbg("positive originally\n");
/* inode may be NULL */
AuDebugOn(inode && (inode->i_mode & S_IFMT) != orig_h.mode);
if (!tmp_h.inode) {
AuDbg("positive --> negative\n");
/* or bypassing aufs */
au_hide(dentry);
if (tmp->di_bwh >= 0 && tmp->di_bwh <= dinfo->di_bstart)
dinfo->di_bwh = tmp->di_bwh;
if (inode)
err = au_refresh_hinode_self(inode);
au_dbg_verify_dinode(dentry);
} else if (orig_h.mode == tmp_h.mode) {
AuDbg("positive --> positive, same type\n");
if (!S_ISDIR(orig_h.mode)
&& dinfo->di_bstart > tmp->di_bstart) {
/*
* similar to the behaviour of removing and
* creating.
*/
au_hide(dentry);
if (inode)
err = au_refresh_hinode_self(inode);
au_dbg_verify_dinode(dentry);
} else {
/* fill empty slots */
if (dinfo->di_bstart > tmp->di_bstart)
dinfo->di_bstart = tmp->di_bstart;
if (dinfo->di_bend < tmp->di_bend)
dinfo->di_bend = tmp->di_bend;
dinfo->di_bwh = tmp->di_bwh;
dinfo->di_bdiropq = tmp->di_bdiropq;
hd = tmp->di_hdentry;
bend = dinfo->di_bend;
for (bindex = tmp->di_bstart; bindex <= bend;
bindex++) {
if (au_h_dptr(dentry, bindex))
continue;
h_dentry = hd[bindex].hd_dentry;
if (!h_dentry)
continue;
h_inode = h_dentry->d_inode;
AuDebugOn(!h_inode);
AuDebugOn(orig_h.mode
!= (h_inode->i_mode
& S_IFMT));
au_set_h_dptr(dentry, bindex,
dget(h_dentry));
}
err = au_refresh_hinode(inode, dentry);
au_dbg_verify_dinode(dentry);
}
} else {
AuDbg("positive --> positive, different type\n");
/* similar to the behaviour of removing and creating */
au_hide(dentry);
if (inode)
err = au_refresh_hinode_self(inode);
au_dbg_verify_dinode(dentry);
}
}
out:
return err;
}
