static int find_lower_writable(struct au_mvd_args *a)
{
struct super_block *sb;
aufs_bindex_t bindex, bend;
struct au_branch *br;
sb = a->sb;
bindex = a->mvd_bsrc;
bend = au_sbend(sb);
if (a->mvdown.flags & AUFS_MVDOWN_FHSM_LOWER)
for (bindex++; bindex <= bend; bindex++) {
br = au_sbr(sb, bindex);
if (au_br_fhsm(br->br_perm)
&& (!(au_br_sb(br)->s_flags & MS_RDONLY)))
return bindex;
}
else if (!(a->mvdown.flags & AUFS_MVDOWN_ROLOWER))
for (bindex++; bindex <= bend; bindex++) {
br = au_sbr(sb, bindex);
if (!au_br_rdonly(br))
return bindex;
}
else
for (bindex++; bindex <= bend; bindex++) {
br = au_sbr(sb, bindex);
if (!(au_br_sb(br)->s_flags & MS_RDONLY)) {
if (au_br_rdonly(br))
a->mvdown.flags
|= AUFS_MVDOWN_ROLOWER_R;
return bindex;
}
}
return -1;
}
static ssize_t au_fhsm_read(struct file *file, char __user *buf, size_t count,
loff_t *pos)
{
ssize_t err;
int readable;
aufs_bindex_t nfhsm, bindex, bend;
struct au_sbinfo *sbinfo;
struct au_fhsm *fhsm;
struct au_branch *br;
struct super_block *sb;
err = 0;
sbinfo = file->private_data;
fhsm = &sbinfo->si_fhsm;
need_data:
spin_lock_irq(&fhsm->fhsm_wqh.lock);
if (!atomic_read(&fhsm->fhsm_readable)) {
if (vfsub_file_flags(file) & O_NONBLOCK)
err = -EAGAIN;
else
err = wait_event_interruptible_locked_irq
(fhsm->fhsm_wqh,
atomic_read(&fhsm->fhsm_readable));
}
spin_unlock_irq(&fhsm->fhsm_wqh.lock);
if (unlikely(err))
goto out;
/* sb may already be dead */
au_rw_read_lock(&sbinfo->si_rwsem);
readable = atomic_read(&fhsm->fhsm_readable);
if (readable > 0) {
sb = sbinfo->si_sb;
AuDebugOn(!sb);
/* exclude the bottom branch */
nfhsm = 0;
bend = au_fhsm_bottom(sb);
for (bindex = 0; bindex < bend; bindex++) {
br = au_sbr(sb, bindex);
if (au_br_fhsm(br->br_perm))
nfhsm++;
}
err = -EMSGSIZE;
if (nfhsm * sizeof(struct aufs_stbr) <= count) {
atomic_set(&fhsm->fhsm_readable, 0);
err = au_fhsm_do_read(sbinfo->si_sb, (void __user *)buf,
count);
}
}
au_rw_read_unlock(&sbinfo->si_rwsem);
if (!readable)
goto need_data;
out:
return err;
}
void au_fhsm_wrote_all(struct super_block *sb, int force)
{
aufs_bindex_t bindex, bend;
struct au_branch *br;
/* exclude the bottom */
bend = au_fhsm_bottom(sb);
for (bindex = 0; bindex < bend; bindex++) {
br = au_sbr(sb, bindex);
if (au_br_fhsm(br->br_perm))
au_fhsm_wrote(sb, bindex, force);
}
}
static ssize_t au_fhsm_do_read(struct super_block *sb,
struct aufs_stbr __user *stbr, size_t count)
{
ssize_t err;
int nstbr;
aufs_bindex_t bindex, bend;
struct au_branch *br;
struct au_br_fhsm *bf;
/* except the bottom branch */
err = 0;
nstbr = 0;
bend = au_fhsm_bottom(sb);
for (bindex = 0; !err && bindex < bend; bindex++) {
br = au_sbr(sb, bindex);
if (!au_br_fhsm(br->br_perm))
continue;
bf = br->br_fhsm;
mutex_lock(&bf->bf_lock);
if (bf->bf_readable) {
err = -EFAULT;
if (count >= sizeof(*stbr))
err = au_fhsm_do_read_one(stbr++, &bf->bf_stfs,
br->br_id);
if (!err) {
bf->bf_readable = 0;
count -= sizeof(*stbr);
nstbr++;
}
}
mutex_unlock(&bf->bf_lock);
}
if (!err)
err = sizeof(*stbr) * nstbr;
return err;
}
int au_opts_verify(struct super_block *sb, unsigned long sb_flags,
unsigned int pending)
{
int err, fhsm;
aufs_bindex_t bindex, bend;
unsigned char do_plink, skip, do_free;
struct au_branch *br;
struct au_wbr *wbr;
struct dentry *root;
struct inode *dir, *h_dir;
struct au_sbinfo *sbinfo;
struct au_hinode *hdir;
SiMustAnyLock(sb);
sbinfo = au_sbi(sb);
AuDebugOn(!(sbinfo->si_mntflags & AuOptMask_UDBA));
if (!(sb_flags & MS_RDONLY)) {
if (unlikely(!au_br_writable(au_sbr_perm(sb, 0))))
pr_warn("first branch should be rw\n");
if (unlikely(au_opt_test(sbinfo->si_mntflags, SHWH)))
pr_warn("shwh should be used with ro\n");
}
if (au_opt_test((sbinfo->si_mntflags | pending), UDBA_HNOTIFY)
&& !au_opt_test(sbinfo->si_mntflags, XINO))
pr_warn("udba=*notify requires xino\n");
if (au_opt_test(sbinfo->si_mntflags, DIRPERM1))
pr_warn("dirperm1 breaks the protection"
" by the permission bits on the lower branch\n");
err = 0;
fhsm = 0;
root = sb->s_root;
dir = root->d_inode;
do_plink = !!au_opt_test(sbinfo->si_mntflags, PLINK);
bend = au_sbend(sb);
for (bindex = 0; !err && bindex <= bend; bindex++) {
skip = 0;
h_dir = au_h_iptr(dir, bindex);
br = au_sbr(sb, bindex);
if ((br->br_perm & AuBrAttr_ICEX)
&& !h_dir->i_op->listxattr)
br->br_perm &= ~AuBrAttr_ICEX;
#if 0
if ((br->br_perm & AuBrAttr_ICEX_SEC)
&& (au_br_sb(br)->s_flags & MS_NOSEC))
br->br_perm &= ~AuBrAttr_ICEX_SEC;
#endif
do_free = 0;
wbr = br->br_wbr;
if (wbr)
wbr_wh_read_lock(wbr);
if (!au_br_writable(br->br_perm)) {
do_free = !!wbr;
skip = (!wbr
|| (!wbr->wbr_whbase
&& !wbr->wbr_plink
&& !wbr->wbr_orph));
} else if (!au_br_wh_linkable(br->br_perm)) {
/* skip = (!br->br_whbase && !br->br_orph); */
skip = (!wbr || !wbr->wbr_whbase);
if (skip && wbr) {
if (do_plink)
skip = !!wbr->wbr_plink;
else
skip = !wbr->wbr_plink;
}
} else {
/* skip = (br->br_whbase && br->br_ohph); */
skip = (wbr && wbr->wbr_whbase);
if (skip) {
if (do_plink)
skip = !!wbr->wbr_plink;
else
skip = !wbr->wbr_plink;
}
}
if (wbr)
wbr_wh_read_unlock(wbr);
if (au_br_fhsm(br->br_perm)) {
fhsm++;
AuDebugOn(!br->br_fhsm);
}
if (skip)
continue;
hdir = au_hi(dir, bindex);
au_hn_imtx_lock_nested(hdir, AuLsc_I_PARENT);
if (wbr)
wbr_wh_write_lock(wbr);
err = au_wh_init(br, sb);
if (wbr)
wbr_wh_write_unlock(wbr);
au_hn_imtx_unlock(hdir);
if (!err && do_free) {
kfree(wbr);
br->br_wbr = NULL;
}
}
if (fhsm >= 2) {
au_fset_si(sbinfo, FHSM);
for (bindex = bend; bindex >= 0; bindex--) {
br = au_sbr(sb, bindex);
if (au_br_fhsm(br->br_perm)) {
au_fhsm_set_bottom(sb, bindex);
break;
}
}
} else {
au_fclr_si(sbinfo, FHSM);
au_fhsm_set_bottom(sb, -1);
}
return err;
}
