/*
* when we have to copyup the renaming entry, do it with the rename-target name
* in order to minimize the cost (the later actual rename is unnecessary).
* otherwise rename it on the target branch.
*/
static int au_ren_or_cpup(struct au_ren_args *a)
{
int err;
struct dentry *d;
d = a->src_dentry;
if (au_dbstart(d) == a->btgt) {
a->h_path.dentry = a->dst_h_dentry;
if (au_ftest_ren(a->flags, DIROPQ)
&& au_dbdiropq(d) == a->btgt)
au_fclr_ren(a->flags, DIROPQ);
AuDebugOn(au_dbstart(d) != a->btgt);
err = vfsub_rename(a->src_h_dir, au_h_dptr(d, a->btgt),
a->dst_h_dir, &a->h_path);
} else {
struct mutex *h_mtx = &a->src_h_dentry->d_inode->i_mutex;
struct file *h_file;
au_fset_ren(a->flags, CPUP);
mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
au_set_dbstart(d, a->btgt);
au_set_h_dptr(d, a->btgt, dget(a->dst_h_dentry));
h_file = au_h_open_pre(d, a->src_bstart);
if (IS_ERR(h_file)) {
err = PTR_ERR(h_file);
h_file = NULL;
} else
err = au_sio_cpup_single(d, a->btgt, a->src_bstart, -1,
!AuCpup_DTIME, a->dst_parent);
mutex_unlock(h_mtx);
au_h_open_post(d, a->src_bstart, h_file);
if (!err) {
d = a->dst_dentry;
au_set_h_dptr(d, a->btgt, NULL);
au_update_dbstart(d);
} else {
au_set_h_dptr(d, a->btgt, NULL);
au_set_dbstart(d, a->src_bstart);
}
}
if (!err && a->h_dst)
/* it will be set to dinfo later */
dget(a->h_dst);
return err;
}
static void au_ren_rev_cpup(int err, struct au_ren_args *a)
{
int rerr;
a->h_path.dentry = a->dst_h_dentry;
rerr = vfsub_unlink(a->dst_h_dir, &a->h_path, /*force*/0);
au_set_h_dptr(a->src_dentry, a->btgt, NULL);
au_set_dbstart(a->src_dentry, a->src_bstart);
if (rerr)
RevertFailure("unlink %.*s", AuDLNPair(a->dst_h_dentry));
}
/* side effect: sets whlist and h_dentry */
static int au_ren_may_dir(struct au_ren_args *a)
{
int err;
unsigned int rdhash;
struct dentry *d;
d = a->dst_dentry;
SiMustAnyLock(d->d_sb);
err = 0;
if (au_ftest_ren(a->flags, ISDIR) && a->dst_inode) {
rdhash = au_sbi(d->d_sb)->si_rdhash;
if (!rdhash)
rdhash = au_rdhash_est(au_dir_size(/*file*/NULL, d));
err = au_nhash_alloc(&a->whlist, rdhash, GFP_NOFS);
if (unlikely(err))
goto out;
au_set_dbstart(d, a->dst_bstart);
err = may_rename_dstdir(d, &a->whlist);
au_set_dbstart(d, a->btgt);
}
a->dst_h_dentry = au_h_dptr(d, au_dbstart(d));
if (unlikely(err))
goto out;
d = a->src_dentry;
a->src_h_dentry = au_h_dptr(d, au_dbstart(d));
if (au_ftest_ren(a->flags, ISDIR)) {
err = may_rename_srcdir(d, a->btgt);
if (unlikely(err)) {
au_nhash_wh_free(&a->whlist);
a->whlist.nh_num = 0;
}
}
out:
return err;
}
/*
* copy-down the file and unlink the bsrc file.
* - unlink the bdst whout if exist
* - copy-down the file (with whtmp name and rename)
* - unlink the bsrc file
*/
static int au_do_mvdown(const unsigned char dmsg, struct au_mvd_args *a)
{
int err;
err = au_do_mkdir(dmsg, a);
if (!err)
err = au_do_lock(dmsg, a);
if (unlikely(err))
goto out;
/*
* do not revert the activities we made on bdst since they should be
* harmless in aufs.
*/
err = au_do_cpdown(dmsg, a);
if (!err)
err = au_do_unlink_wh(dmsg, a);
if (!err && !(a->mvdown.flags & AUFS_MVDOWN_KUPPER))
err = au_do_unlink(dmsg, a);
if (unlikely(err))
goto out_unlock;
AuDbg("%pd2, 0x%x, %d --> %d\n",
a->dentry, a->mvdown.flags, a->mvd_bsrc, a->mvd_bdst);
if (find_lower_writable(a) < 0)
a->mvdown.flags |= AUFS_MVDOWN_BOTTOM;
if (a->mvdown.flags & AUFS_MVDOWN_STFS)
au_do_stfs(dmsg, a);
/* maintain internal array */
if (!(a->mvdown.flags & AUFS_MVDOWN_KUPPER)) {
au_set_h_dptr(a->dentry, a->mvd_bsrc, NULL);
au_set_dbstart(a->dentry, a->mvd_bdst);
au_set_h_iptr(a->inode, a->mvd_bsrc, NULL, /*flags*/0);
au_set_ibstart(a->inode, a->mvd_bdst);
}
if (au_dbend(a->dentry) < a->mvd_bdst)
au_set_dbend(a->dentry, a->mvd_bdst);
if (au_ibend(a->inode) < a->mvd_bdst)
au_set_ibend(a->inode, a->mvd_bdst);
out_unlock:
au_do_unlock(dmsg, a);
out:
AuTraceErr(err);
return err;
}
void au_update_dbstart(struct dentry *dentry)
{
aufs_bindex_t bindex, bend;
struct dentry *h_dentry;
bend = au_dbend(dentry);
for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
h_dentry = au_h_dptr(dentry, bindex);
if (!h_dentry)
continue;
if (h_dentry->d_inode) {
au_set_dbstart(dentry, bindex);
return;
}
au_set_h_dptr(dentry, bindex, NULL);
}
}
static int au_wr_dir_cpup(struct dentry *dentry, struct dentry *parent,
const unsigned char add_entry, aufs_bindex_t bcpup,
aufs_bindex_t bstart)
{
int err;
struct dentry *h_parent;
struct inode *h_dir;
if (add_entry) {
au_update_dbstart(dentry);
IMustLock(parent->d_inode);
} else
di_write_lock_parent(parent);
err = 0;
if (!au_h_dptr(parent, bcpup)) {
if (bstart < bcpup)
err = au_cpdown_dirs(dentry, bcpup);
else
err = au_cpup_dirs(dentry, bcpup);
}
if (!err && add_entry) {
h_parent = au_h_dptr(parent, bcpup);
h_dir = h_parent->d_inode;
mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
err = au_lkup_neg(dentry, bcpup);
/* todo: no unlock here */
mutex_unlock(&h_dir->i_mutex);
if (bstart < bcpup && au_dbstart(dentry) < 0) {
au_set_dbstart(dentry, 0);
au_update_dbrange(dentry, /*do_put_zero*/0);
}
}
if (!add_entry)
di_write_unlock(parent);
if (!err)
err = bcpup; /* success */
return err;
}
void au_update_dbstart(struct dentry *dentry)
{
aufs_bindex_t bindex,
bstart = au_dbstart(dentry),
bend = au_dbend(dentry);
struct dentry *h_dentry;
LKTRTrace("%.*s\n", AuDLNPair(dentry));
DiMustWriteLock(dentry);
for (bindex = bstart; bindex <= bend; bindex++) {
h_dentry = au_h_dptr(dentry, bindex);
if (!h_dentry)
continue;
if (h_dentry->d_inode) {
au_set_dbstart(dentry, bindex);
return;
}
au_set_h_dptr(dentry, bindex, NULL);
}
}
int aufs_rename(struct inode *_src_dir, struct dentry *_src_dentry,
struct inode *_dst_dir, struct dentry *_dst_dentry)
{
int err, flags;
/* reduce stack space */
struct au_ren_args *a;
AuDbg("%.*s, %.*s\n", AuDLNPair(_src_dentry), AuDLNPair(_dst_dentry));
IMustLock(_src_dir);
IMustLock(_dst_dir);
err = -ENOMEM;
BUILD_BUG_ON(sizeof(*a) > PAGE_SIZE);
a = kzalloc(sizeof(*a), GFP_NOFS);
if (unlikely(!a))
goto out;
a->src_dir = _src_dir;
a->src_dentry = _src_dentry;
a->src_inode = a->src_dentry->d_inode;
a->src_parent = a->src_dentry->d_parent; /* dir inode is locked */
a->dst_dir = _dst_dir;
a->dst_dentry = _dst_dentry;
a->dst_inode = a->dst_dentry->d_inode;
a->dst_parent = a->dst_dentry->d_parent; /* dir inode is locked */
if (a->dst_inode) {
IMustLock(a->dst_inode);
au_igrab(a->dst_inode);
}
err = -ENOTDIR;
flags = AuLock_FLUSH | AuLock_NOPLM | AuLock_GEN;
if (S_ISDIR(a->src_inode->i_mode)) {
au_fset_ren(a->flags, ISDIR);
if (unlikely(a->dst_inode && !S_ISDIR(a->dst_inode->i_mode)))
goto out_free;
err = aufs_read_and_write_lock2(a->dst_dentry, a->src_dentry,
AuLock_DIR | flags);
} else
err = aufs_read_and_write_lock2(a->dst_dentry, a->src_dentry,
flags);
if (unlikely(err))
goto out_free;
err = au_d_hashed_positive(a->src_dentry);
if (unlikely(err))
goto out_unlock;
err = -ENOENT;
if (a->dst_inode) {
/*
* If it is a dir, VFS unhash dst_dentry before this
* function. It means we cannot rely upon d_unhashed().
*/
if (unlikely(!a->dst_inode->i_nlink))
goto out_unlock;
if (!S_ISDIR(a->dst_inode->i_mode)) {
err = au_d_hashed_positive(a->dst_dentry);
if (unlikely(err))
goto out_unlock;
} else if (unlikely(IS_DEADDIR(a->dst_inode)))
goto out_unlock;
} else if (unlikely(d_unhashed(a->dst_dentry)))
goto out_unlock;
au_fset_ren(a->flags, ISSAMEDIR); /* temporary */
di_write_lock_parent(a->dst_parent);
/* which branch we process */
err = au_ren_wbr(a);
if (unlikely(err < 0))
goto out_parent;
a->br = au_sbr(a->dst_dentry->d_sb, a->btgt);
a->h_path.mnt = a->br->br_mnt;
/* are they available to be renamed */
err = au_ren_may_dir(a);
if (unlikely(err))
goto out_children;
/* prepare the writable parent dir on the same branch */
if (a->dst_bstart == a->btgt) {
au_fset_ren(a->flags, WHDST);
} else {
err = au_cpup_dirs(a->dst_dentry, a->btgt);
if (unlikely(err))
goto out_children;
}
if (a->src_dir != a->dst_dir) {
/*
* this temporary unlock is safe,
* because both dir->i_mutex are locked.
*/
di_write_unlock(a->dst_parent);
di_write_lock_parent(a->src_parent);
err = au_wr_dir_need_wh(a->src_dentry,
au_ftest_ren(a->flags, ISDIR),
&a->btgt);
di_write_unlock(a->src_parent);
di_write_lock2_parent(a->src_parent, a->dst_parent, /*isdir*/1);
au_fclr_ren(a->flags, ISSAMEDIR);
} else
err = au_wr_dir_need_wh(a->src_dentry,
au_ftest_ren(a->flags, ISDIR),
&a->btgt);
if (unlikely(err < 0))
goto out_children;
if (err)
au_fset_ren(a->flags, WHSRC);
/* lock them all */
err = au_ren_lock(a);
if (unlikely(err))
goto out_children;
if (!au_opt_test(au_mntflags(a->dst_dir->i_sb), UDBA_NONE))
err = au_may_ren(a);
else if (unlikely(a->dst_dentry->d_name.len > AUFS_MAX_NAMELEN))
err = -ENAMETOOLONG;
if (unlikely(err))
goto out_hdir;
/* store timestamps to be revertible */
au_ren_dt(a);
/* here we go */
err = do_rename(a);
if (unlikely(err))
goto out_dt;
/* update dir attributes */
au_ren_refresh_dir(a);
/* dput/iput all lower dentries */
au_ren_refresh(a);
goto out_hdir; /* success */
out_dt:
au_ren_rev_dt(err, a);
out_hdir:
au_ren_unlock(a);
out_children:
au_nhash_wh_free(&a->whlist);
if (err && a->dst_inode && a->dst_bstart != a->btgt) {
AuDbg("bstart %d, btgt %d\n", a->dst_bstart, a->btgt);
au_set_h_dptr(a->dst_dentry, a->btgt, NULL);
au_set_dbstart(a->dst_dentry, a->dst_bstart);
}
out_parent:
if (!err)
d_move(a->src_dentry, a->dst_dentry);
else {
au_update_dbstart(a->dst_dentry);
if (!a->dst_inode)
d_drop(a->dst_dentry);
}
if (au_ftest_ren(a->flags, ISSAMEDIR))
di_write_unlock(a->dst_parent);
else
di_write_unlock2(a->src_parent, a->dst_parent);
out_unlock:
aufs_read_and_write_unlock2(a->dst_dentry, a->src_dentry);
out_free:
iput(a->dst_inode);
if (a->thargs)
au_whtmp_rmdir_free(a->thargs);
kfree(a);
out:
AuTraceErr(err);
return err;
}
/*
* decide the branch and the parent dir where we will create a new entry.
* returns new bindex or an error.
* copyup the parent dir if needed.
*/
int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
struct au_wr_dir_args *args)
{
int err;
aufs_bindex_t bcpup, bstart, src_bstart;
const unsigned char add_entry = !!au_ftest_wrdir(args->flags,
ADD_ENTRY);
struct super_block *sb;
struct dentry *parent;
struct au_sbinfo *sbinfo;
sb = dentry->d_sb;
sbinfo = au_sbi(sb);
parent = dget_parent(dentry);
bstart = au_dbstart(dentry);
bcpup = bstart;
if (args->force_btgt < 0) {
if (src_dentry) {
src_bstart = au_dbstart(src_dentry);
if (src_bstart < bstart)
bcpup = src_bstart;
} else if (add_entry) {
err = AuWbrCreate(sbinfo, dentry,
au_ftest_wrdir(args->flags, ISDIR));
bcpup = err;
}
if (bcpup < 0 || au_test_ro(sb, bcpup, dentry->d_inode)) {
if (add_entry)
err = AuWbrCopyup(sbinfo, dentry);
else {
if (!IS_ROOT(dentry)) {
di_read_lock_parent(parent, !AuLock_IR);
err = AuWbrCopyup(sbinfo, dentry);
di_read_unlock(parent, !AuLock_IR);
} else
err = AuWbrCopyup(sbinfo, dentry);
}
bcpup = err;
if (unlikely(err < 0))
goto out;
}
} else {
bcpup = args->force_btgt;
AuDebugOn(au_test_ro(sb, bcpup, dentry->d_inode));
}
AuDbg("bstart %d, bcpup %d\n", bstart, bcpup);
err = bcpup;
if (bcpup == bstart)
goto out; /* success */
/* copyup the new parent into the branch we process */
err = au_wr_dir_cpup(dentry, parent, add_entry, bcpup, bstart);
if (err >= 0) {
if (!dentry->d_inode) {
au_set_h_dptr(dentry, bstart, NULL);
au_set_dbstart(dentry, bcpup);
au_set_dbend(dentry, bcpup);
}
AuDebugOn(add_entry && !au_h_dptr(dentry, bcpup));
}
out:
dput(parent);
return err;
}
/*
* returns positive/negative dentry, NULL or an error.
* NULL means whiteout-ed or not-found.
*/
static struct dentry*
au_do_lookup(struct dentry *h_parent, struct dentry *dentry,
aufs_bindex_t bindex, struct qstr *wh_name,
struct au_do_lookup_args *args)
{
struct dentry *h_dentry;
struct inode *h_inode, *inode;
struct au_branch *br;
int wh_found, opq;
unsigned char wh_able;
const unsigned char allow_neg = !!au_ftest_lkup(args->flags, ALLOW_NEG);
wh_found = 0;
br = au_sbr(dentry->d_sb, bindex);
wh_able = !!au_br_whable(br->br_perm);
if (wh_able)
wh_found = au_wh_test(h_parent, wh_name, br, /*try_sio*/0);
h_dentry = ERR_PTR(wh_found);
if (!wh_found)
goto real_lookup;
if (unlikely(wh_found < 0))
goto out;
/* We found a whiteout */
/* au_set_dbend(dentry, bindex); */
au_set_dbwh(dentry, bindex);
if (!allow_neg)
return NULL; /* success */
real_lookup:
h_dentry = au_lkup_one(&dentry->d_name, h_parent, br, args->nd);
if (IS_ERR(h_dentry))
goto out;
h_inode = h_dentry->d_inode;
if (!h_inode) {
if (!allow_neg)
goto out_neg;
} else if (wh_found
|| (args->type && args->type != (h_inode->i_mode & S_IFMT)))
goto out_neg;
if (au_dbend(dentry) <= bindex)
au_set_dbend(dentry, bindex);
if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
au_set_dbstart(dentry, bindex);
au_set_h_dptr(dentry, bindex, h_dentry);
inode = dentry->d_inode;
if (!h_inode || !S_ISDIR(h_inode->i_mode) || !wh_able
|| (inode && !S_ISDIR(inode->i_mode)))
goto out; /* success */
mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
opq = au_diropq_test(h_dentry, br);
mutex_unlock(&h_inode->i_mutex);
if (opq > 0)
au_set_dbdiropq(dentry, bindex);
else if (unlikely(opq < 0)) {
au_set_h_dptr(dentry, bindex, NULL);
h_dentry = ERR_PTR(opq);
}
goto out;
out_neg:
dput(h_dentry);
h_dentry = NULL;
out:
return h_dentry;
}
/*
* 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,
struct nameidata *nd)
{
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,
.nd = nd
};
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, %.*s, err %d\n",
AuDLNPair(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 = au_lkup_one(name, parent, br, /*nd*/NULL);
else {
struct au_lkup_one_args args = {
.errp = &dentry,
.name = name,
.h_parent = parent,
.br = br,
.nd = NULL
};
wkq_err = au_wkq_wait(au_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 err;
struct dentry *parent, *h_parent, *h_dentry;
parent = dget_parent(dentry);
h_parent = au_h_dptr(parent, bindex);
h_dentry = au_sio_lkup_one(&dentry->d_name, h_parent,
au_sbr(dentry->d_sb, bindex));
err = PTR_ERR(h_dentry);
if (IS_ERR(h_dentry))
goto out;
if (unlikely(h_dentry->d_inode)) {
err = -EIO;
AuIOErr("%.*s should be negative on b%d.\n",
AuDLNPair(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;
}
/*
* initial procedure of adding a new entry.
* prepare writable branch and the parent dir, lock it,
* and lookup whiteout for the new entry.
*/
static struct dentry*
lock_hdir_lkup_wh(struct dentry *dentry, struct au_dtime *dt,
struct dentry *src_dentry, struct au_pin *pin,
struct au_wr_dir_args *wr_dir_args)
{
struct dentry *wh_dentry, *h_parent;
struct super_block *sb;
struct au_branch *br;
int err;
unsigned int udba;
aufs_bindex_t bcpup;
AuDbg("%.*s\n", AuDLNPair(dentry));
err = au_wr_dir(dentry, src_dentry, wr_dir_args);
bcpup = err;
wh_dentry = ERR_PTR(err);
if (unlikely(err < 0))
goto out;
sb = dentry->d_sb;
udba = au_opt_udba(sb);
err = au_pin(pin, dentry, bcpup, udba,
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
wh_dentry = ERR_PTR(err);
if (unlikely(err))
goto out;
h_parent = au_pinned_h_parent(pin);
if (udba != AuOpt_UDBA_NONE
&& au_dbstart(dentry) == bcpup)
err = au_may_add(dentry, bcpup, h_parent,
au_ftest_wrdir(wr_dir_args->flags, ISDIR));
else if (unlikely(dentry->d_name.len > AUFS_MAX_NAMELEN))
err = -ENAMETOOLONG;
wh_dentry = ERR_PTR(err);
if (unlikely(err))
goto out_unpin;
br = au_sbr(sb, bcpup);
if (dt) {
struct path tmp = {
.dentry = h_parent,
.mnt = br->br_mnt
};
au_dtime_store(dt, au_pinned_parent(pin), &tmp);
}
wh_dentry = NULL;
if (bcpup != au_dbwh(dentry))
goto out; /* success */
wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, br);
out_unpin:
if (IS_ERR(wh_dentry))
au_unpin(pin);
out:
return wh_dentry;
}
/* ---------------------------------------------------------------------- */
enum { Mknod, Symlink, Creat };
struct simple_arg {
int type;
union {
struct {
int mode;
struct nameidata *nd;
} c;
struct {
const char *symname;
} s;
struct {
int mode;
dev_t dev;
} m;
} u;
};
static int add_simple(struct inode *dir, struct dentry *dentry,
struct simple_arg *arg)
{
int err;
aufs_bindex_t bstart;
unsigned char created;
struct au_dtime dt;
struct au_pin pin;
struct path h_path;
struct dentry *wh_dentry, *parent;
struct inode *h_dir;
struct au_wr_dir_args wr_dir_args = {
.force_btgt = -1,
.flags = AuWrDir_ADD_ENTRY
};
AuDbg("%.*s\n", AuDLNPair(dentry));
IMustLock(dir);
parent = dentry->d_parent; /* dir inode is locked */
err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
if (unlikely(err))
goto out;
err = au_d_may_add(dentry);
if (unlikely(err))
goto out_unlock;
di_write_lock_parent(parent);
wh_dentry = lock_hdir_lkup_wh(dentry, &dt, /*src_dentry*/NULL, &pin,
&wr_dir_args);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out_parent;
bstart = au_dbstart(dentry);
h_path.dentry = au_h_dptr(dentry, bstart);
h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
h_dir = au_pinned_h_dir(&pin);
switch (arg->type) {
case Creat:
err = vfsub_create(h_dir, &h_path, arg->u.c.mode);
break;
case Symlink:
err = vfsub_symlink(h_dir, &h_path, arg->u.s.symname);
break;
case Mknod:
err = vfsub_mknod(h_dir, &h_path, arg->u.m.mode, arg->u.m.dev);
break;
default:
BUG();
}
created = !err;
if (!err)
err = epilog(dir, bstart, wh_dentry, dentry);
/* revert */
if (unlikely(created && err && h_path.dentry->d_inode)) {
int rerr;
rerr = vfsub_unlink(h_dir, &h_path, /*force*/0);
if (rerr) {
AuIOErr("%.*s revert failure(%d, %d)\n",
AuDLNPair(dentry), err, rerr);
err = -EIO;
}
au_dtime_revert(&dt);
}
au_unpin(&pin);
dput(wh_dentry);
out_parent:
di_write_unlock(parent);
out_unlock:
if (unlikely(err)) {
au_update_dbstart(dentry);
d_drop(dentry);
}
aufs_read_unlock(dentry, AuLock_DW);
out:
return err;
}
int aufs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
struct simple_arg arg = {
.type = Mknod,
.u.m = {
.mode = mode,
.dev = dev
}
};
return add_simple(dir, dentry, &arg);
}
int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
{
struct simple_arg arg = {
.type = Symlink,
.u.s.symname = symname
};
return add_simple(dir, dentry, &arg);
}
int aufs_create(struct inode *dir, struct dentry *dentry, int mode,
struct nameidata *nd)
{
struct simple_arg arg = {
.type = Creat,
.u.c = {
.mode = mode,
.nd = nd
}
};
return add_simple(dir, dentry, &arg);
}
/* ---------------------------------------------------------------------- */
struct au_link_args {
aufs_bindex_t bdst, bsrc;
struct au_pin pin;
struct path h_path;
struct dentry *src_parent, *parent;
};
static int au_cpup_before_link(struct dentry *src_dentry,
struct au_link_args *a)
{
int err;
struct dentry *h_src_dentry;
struct mutex *h_mtx;
struct file *h_file;
di_read_lock_parent(a->src_parent, AuLock_IR);
err = au_test_and_cpup_dirs(src_dentry, a->bdst);
if (unlikely(err))
goto out;
h_src_dentry = au_h_dptr(src_dentry, a->bsrc);
h_mtx = &h_src_dentry->d_inode->i_mutex;
err = au_pin(&a->pin, src_dentry, a->bdst,
au_opt_udba(src_dentry->d_sb),
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
if (unlikely(err))
goto out;
mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
h_file = au_h_open_pre(src_dentry, a->bsrc);
if (IS_ERR(h_file)) {
err = PTR_ERR(h_file);
h_file = NULL;
} else
err = au_sio_cpup_simple(src_dentry, a->bdst, a->bsrc,
AuCpup_DTIME /* | AuCpup_KEEPLINO */);
mutex_unlock(h_mtx);
au_h_open_post(src_dentry, a->bsrc, h_file);
au_unpin(&a->pin);
out:
di_read_unlock(a->src_parent, AuLock_IR);
return err;
}
static int au_cpup_or_link(struct dentry *src_dentry, struct au_link_args *a)
{
int err;
unsigned char plink;
struct inode *h_inode, *inode;
struct dentry *h_src_dentry;
struct super_block *sb;
struct file *h_file;
plink = 0;
h_inode = NULL;
sb = src_dentry->d_sb;
inode = src_dentry->d_inode;
if (au_ibstart(inode) <= a->bdst)
h_inode = au_h_iptr(inode, a->bdst);
if (!h_inode || !h_inode->i_nlink) {
/* copyup src_dentry as the name of dentry. */
au_set_dbstart(src_dentry, a->bdst);
au_set_h_dptr(src_dentry, a->bdst, dget(a->h_path.dentry));
h_inode = au_h_dptr(src_dentry, a->bsrc)->d_inode;
mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
h_file = au_h_open_pre(src_dentry, a->bsrc);
if (IS_ERR(h_file)) {
err = PTR_ERR(h_file);
h_file = NULL;
} else
err = au_sio_cpup_single(src_dentry, a->bdst, a->bsrc,
-1, AuCpup_KEEPLINO,
a->parent);
mutex_unlock(&h_inode->i_mutex);
au_h_open_post(src_dentry, a->bsrc, h_file);
au_set_h_dptr(src_dentry, a->bdst, NULL);
au_set_dbstart(src_dentry, a->bsrc);
} else {
/* the inode of src_dentry already exists on a.bdst branch */
h_src_dentry = d_find_alias(h_inode);
if (!h_src_dentry && au_plink_test(inode)) {
plink = 1;
h_src_dentry = au_plink_lkup(inode, a->bdst);
err = PTR_ERR(h_src_dentry);
if (IS_ERR(h_src_dentry))
goto out;
if (unlikely(!h_src_dentry->d_inode)) {
dput(h_src_dentry);
h_src_dentry = NULL;
}
}
if (h_src_dentry) {
err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
&a->h_path);
dput(h_src_dentry);
} else {
AuIOErr("no dentry found for hi%lu on b%d\n",
h_inode->i_ino, a->bdst);
err = -EIO;
}
}
if (!err && !plink)
au_plink_append(inode, a->bdst, a->h_path.dentry);
out:
AuTraceErr(err);
return err;
}
/*
* 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, dirperm1;
struct qstr whname;
struct au_do_lookup_args args = {
.flags = 0,
.type = type
};
const struct qstr *name = &dentry->d_name;
struct dentry *parent;
struct super_block *sb;
sb = dentry->d_sb;
err = au_test_shwh(sb, name);
if (unlikely(err))
goto out;
err = au_wh_name_alloc(&whname, name);
if (unlikely(err))
goto out;
isdir = !!d_is_dir(dentry);
if (!type)
au_fset_lkup(args.flags, ALLOW_NEG);
dirperm1 = !!au_opt_test(au_mntflags(sb), DIRPERM1);
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 (d_is_positive(h_dentry))
npositive++;
if (type != S_IFDIR)
break;
continue;
}
h_parent = au_h_dptr(parent, bindex);
if (!h_parent || !d_is_dir(h_parent))
continue;
h_dir = d_inode(h_parent);
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;
if (h_dentry)
au_fclr_lkup(args.flags, ALLOW_NEG);
if (dirperm1)
au_fset_lkup(args.flags, IGNORE_PERM);
if (au_dbwh(dentry) >= 0)
break;
if (!h_dentry)
continue;
if (d_is_negative(h_dentry))
continue;
h_inode = d_inode(h_dentry);
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(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 dentry *dentry;
int wkq_err;
if (!au_test_h_perm_sio(d_inode(parent), 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);
err = PTR_ERR(h_dentry);
if (IS_ERR(h_dentry))
goto out;
if (unlikely(d_is_positive(h_dentry))) {
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;
}