/*
* returns the number of lower positive dentries,
* otherwise an error.
* can be called at unlinking with @type is zero.
*/
int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type)
{
int npositive, err;
aufs_bindex_t bindex, btail, bdiropq;
unsigned char isdir;
struct qstr whname;
struct au_do_lookup_args args = {
.flags = 0,
.type = type
};
const struct qstr *name = &dentry->d_name;
struct dentry *parent;
struct inode *inode;
err = au_test_shwh(dentry->d_sb, name);
if (unlikely(err))
goto out;
err = au_wh_name_alloc(&whname, name);
if (unlikely(err))
goto out;
inode = dentry->d_inode;
isdir = !!(inode && S_ISDIR(inode->i_mode));
if (!type)
au_fset_lkup(args.flags, ALLOW_NEG);
npositive = 0;
parent = dget_parent(dentry);
btail = au_dbtaildir(parent);
for (bindex = bstart; bindex <= btail; bindex++) {
struct dentry *h_parent, *h_dentry;
struct inode *h_inode, *h_dir;
h_dentry = au_h_dptr(dentry, bindex);
if (h_dentry) {
if (h_dentry->d_inode)
npositive++;
if (type != S_IFDIR)
break;
continue;
}
h_parent = au_h_dptr(parent, bindex);
if (!h_parent)
continue;
h_dir = h_parent->d_inode;
if (!h_dir || !S_ISDIR(h_dir->i_mode))
continue;
mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
h_dentry = au_do_lookup(h_parent, dentry, bindex, &whname,
&args);
mutex_unlock(&h_dir->i_mutex);
err = PTR_ERR(h_dentry);
if (IS_ERR(h_dentry))
goto out_parent;
au_fclr_lkup(args.flags, ALLOW_NEG);
if (au_dbwh(dentry) >= 0)
break;
if (!h_dentry)
continue;
h_inode = h_dentry->d_inode;
if (!h_inode)
continue;
npositive++;
if (!args.type)
args.type = h_inode->i_mode & S_IFMT;
if (args.type != S_IFDIR)
break;
else if (isdir) {
/* the type of lower may be different */
bdiropq = au_dbdiropq(dentry);
if (bdiropq >= 0 && bdiropq <= bindex)
break;
}
}
if (npositive) {
AuLabel(positive);
au_update_dbstart(dentry);
}
err = npositive;
if (unlikely(!au_opt_test(au_mntflags(dentry->d_sb), UDBA_NONE)
&& au_dbstart(dentry) < 0)) {
err = -EIO;
AuIOErr("both of real entry and whiteout found, %pd, err %d\n",
dentry, err);
}
out_parent:
dput(parent);
kfree(whname.name);
out:
return err;
}
struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent,
struct au_branch *br)
{
struct dentry *dentry;
int wkq_err;
if (!au_test_h_perm_sio(parent->d_inode, MAY_EXEC))
dentry = vfsub_lkup_one(name, parent);
else {
struct vfsub_lkup_one_args args = {
.errp = &dentry,
.name = name,
.parent = parent
};
wkq_err = au_wkq_wait(vfsub_call_lkup_one, &args);
if (unlikely(wkq_err))
dentry = ERR_PTR(wkq_err);
}
return dentry;
}
/*
* lookup @dentry on @bindex which should be negative.
*/
int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex, int wh)
{
int err;
struct dentry *parent, *h_parent, *h_dentry;
struct au_branch *br;
parent = dget_parent(dentry);
h_parent = au_h_dptr(parent, bindex);
br = au_sbr(dentry->d_sb, bindex);
if (wh)
h_dentry = au_whtmp_lkup(h_parent, br, &dentry->d_name);
else
h_dentry = au_sio_lkup_one(&dentry->d_name, h_parent, br);
err = PTR_ERR(h_dentry);
if (IS_ERR(h_dentry))
goto out;
if (unlikely(h_dentry->d_inode)) {
err = -EIO;
AuIOErr("%pd should be negative on b%d.\n", h_dentry, bindex);
dput(h_dentry);
goto out;
}
err = 0;
if (bindex < au_dbstart(dentry))
au_set_dbstart(dentry, bindex);
if (au_dbend(dentry) < bindex)
au_set_dbend(dentry, bindex);
au_set_h_dptr(dentry, bindex, h_dentry);
out:
dput(parent);
return err;
}
static int au_ready_to_write_wh(struct file *file, loff_t len,
aufs_bindex_t bcpup, struct au_pin *pin)
{
int err;
struct inode *inode, *h_inode;
struct dentry *h_dentry, *hi_wh;
struct au_cp_generic cpg = {
.dentry = file->f_dentry,
.bdst = bcpup,
.bsrc = -1,
.len = len,
.pin = pin
};
au_update_dbstart(cpg.dentry);
inode = cpg.dentry->d_inode;
h_inode = NULL;
if (au_dbstart(cpg.dentry) <= bcpup
&& au_dbend(cpg.dentry) >= bcpup) {
h_dentry = au_h_dptr(cpg.dentry, bcpup);
if (h_dentry)
h_inode = h_dentry->d_inode;
}
hi_wh = au_hi_wh(inode, bcpup);
if (!hi_wh && !h_inode)
err = au_sio_cpup_wh(&cpg, file);
else
/* already copied-up after unlink */
err = au_reopen_wh(file, bcpup, hi_wh);
if (!err
&& (inode->i_nlink > 1
|| (inode->i_state & I_LINKABLE))
&& au_opt_test(au_mntflags(cpg.dentry->d_sb), PLINK))
au_plink_append(inode, bcpup, au_h_dptr(cpg.dentry, bcpup));
return err;
}
/*
* prepare the @file for writing.
*/
int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
{
int err;
aufs_bindex_t dbstart;
struct dentry *parent;
struct inode *inode;
struct super_block *sb;
struct file *h_file;
struct au_cp_generic cpg = {
.dentry = file->f_dentry,
.bdst = -1,
.bsrc = -1,
.len = len,
.pin = pin,
.flags = AuCpup_DTIME
};
sb = cpg.dentry->d_sb;
inode = cpg.dentry->d_inode;
cpg.bsrc = au_fbstart(file);
err = au_test_ro(sb, cpg.bsrc, inode);
if (!err && (au_hf_top(file)->f_mode & FMODE_WRITE)) {
err = au_pin(pin, cpg.dentry, cpg.bsrc, AuOpt_UDBA_NONE,
/*flags*/0);
goto out;
}
/* need to cpup or reopen */
parent = dget_parent(cpg.dentry);
di_write_lock_parent(parent);
err = AuWbrCopyup(au_sbi(sb), cpg.dentry);
cpg.bdst = err;
if (unlikely(err < 0))
goto out_dgrade;
err = 0;
if (!d_unhashed(cpg.dentry) && !au_h_dptr(parent, cpg.bdst)) {
err = au_cpup_dirs(cpg.dentry, cpg.bdst);
if (unlikely(err))
goto out_dgrade;
}
err = au_pin(pin, cpg.dentry, cpg.bdst, AuOpt_UDBA_NONE,
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
if (unlikely(err))
goto out_dgrade;
dbstart = au_dbstart(cpg.dentry);
if (dbstart <= cpg.bdst)
cpg.bsrc = cpg.bdst;
if (dbstart <= cpg.bdst /* just reopen */
|| !d_unhashed(cpg.dentry) /* copyup and reopen */
) {
h_file = au_h_open_pre(cpg.dentry, cpg.bsrc, /*force_wr*/0);
if (IS_ERR(h_file))
err = PTR_ERR(h_file);
else {
di_downgrade_lock(parent, AuLock_IR);
if (dbstart > cpg.bdst)
err = au_sio_cpup_simple(&cpg);
if (!err)
err = au_reopen_nondir(file);
au_h_open_post(cpg.dentry, cpg.bsrc, h_file);
}
} else { /* copyup as wh and reopen */
/*
* since writable hfsplus branch is not supported,
* h_open_pre/post() are unnecessary.
*/
err = au_ready_to_write_wh(file, len, cpg.bdst, pin);
di_downgrade_lock(parent, AuLock_IR);
}
if (!err) {
au_pin_set_parent_lflag(pin, /*lflag*/0);
goto out_dput; /* success */
}
au_unpin(pin);
goto out_unlock;
out_dgrade:
di_downgrade_lock(parent, AuLock_IR);
out_unlock:
di_read_unlock(parent, AuLock_IR);
out_dput:
dput(parent);
out:
return err;
}
/* ---------------------------------------------------------------------- */
int au_do_flush(struct file *file, fl_owner_t id,
int (*flush)(struct file *file, fl_owner_t id))
{
int err;
struct super_block *sb;
struct inode *inode;
inode = file_inode(file);
sb = inode->i_sb;
si_noflush_read_lock(sb);
fi_read_lock(file);
ii_read_lock_child(inode);
err = flush(file, id);
au_cpup_attr_timesizes(inode);
ii_read_unlock(inode);
fi_read_unlock(file);
si_read_unlock(sb);
return err;
}
