int au_xigen_inc(struct inode *inode)
{
int err;
loff_t pos;
ssize_t sz;
__u32 igen;
struct super_block *sb;
struct au_sbinfo *sbinfo;
LKTRTrace("i%lu\n", (unsigned long)inode->i_ino);
err = 0;
sb = inode->i_sb;
if (unlikely(!au_opt_test_xino(au_mntflags(sb))))
goto out;
pos = inode->i_ino;
pos *= sizeof(igen);
igen = inode->i_generation + 1;
sbinfo = au_sbi(sb);
sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xigen, &igen,
sizeof(igen), &pos);
if (sz == sizeof(igen))
goto out; /* success */
err = sz;
if (unlikely(sz >= 0)) {
err = -EIO;
AuIOErr("xigen error (%zd)\n", sz);
}
out:
AuTraceErr(err);
return err;
}
/*
* test if the @wh_name exists under @h_parent.
* @try_sio specifies the necessary of super-io.
*/
int au_wh_test(struct dentry *h_parent, struct qstr *wh_name,
struct au_branch *br, int try_sio)
{
int err;
struct dentry *wh_dentry;
if (!try_sio)
wh_dentry = vfsub_lkup_one(wh_name, h_parent);
else
wh_dentry = au_sio_lkup_one(wh_name, h_parent, br);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out;
err = 0;
if (!wh_dentry->d_inode)
goto out_wh; /* success */
err = 1;
if (S_ISREG(wh_dentry->d_inode->i_mode))
goto out_wh; /* success */
err = -EIO;
AuIOErr("%.*s Invalid whiteout entry type 0%o.\n",
AuDLNPair(wh_dentry), wh_dentry->d_inode->i_mode);
out_wh:
dput(wh_dentry);
out:
return err;
}
int au_xigen_new(struct inode *inode)
{
int err;
loff_t pos;
ssize_t sz;
struct super_block *sb;
struct au_sbinfo *sbinfo;
struct file *file;
LKTRTrace("i%lu\n", inode->i_ino);
err = 0;
/* todo: dirty, at mount time */
if (inode->i_ino == AUFS_ROOT_INO)
goto out;
sb = inode->i_sb;
if (unlikely(!au_opt_test_xino(au_mntflags(sb))))
goto out;
err = -EFBIG;
pos = inode->i_ino;
if (unlikely(Au_LOFF_MAX / sizeof(inode->i_generation) - 1 < pos)) {
AuIOErr1("too large i%lld\n", pos);
goto out;
}
pos *= sizeof(inode->i_generation);
err = 0;
sbinfo = au_sbi(sb);
file = sbinfo->si_xigen;
BUG_ON(!file);
if (i_size_read(file->f_dentry->d_inode)
< pos + sizeof(inode->i_generation)) {
inode->i_generation = atomic_inc_return(&sbinfo->si_xigen_next);
sz = xino_fwrite(sbinfo->si_xwrite, file, &inode->i_generation,
sizeof(inode->i_generation), &pos);
} else
sz = xino_fread(sbinfo->si_xread, file, &inode->i_generation,
sizeof(inode->i_generation), &pos);
if (sz == sizeof(inode->i_generation))
goto out; /* success */
err = sz;
if (unlikely(sz >= 0)) {
err = -EIO;
AuIOErr("xigen error (%zd)\n", sz);
}
out:
AuTraceErr(err);
return err;
}
/*
* final procedure of adding a new entry, except link(2).
* remove whiteout, instantiate, copyup the parent dir's times and size
* and update version.
* if it failed, re-create the removed whiteout.
*/
static int epilog(struct inode *dir, aufs_bindex_t bindex,
struct dentry *wh_dentry, struct dentry *dentry)
{
int err, rerr;
aufs_bindex_t bwh;
struct path h_path;
struct inode *inode, *h_dir;
struct dentry *wh;
bwh = -1;
if (wh_dentry) {
h_dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
IMustLock(h_dir);
AuDebugOn(au_h_iptr(dir, bindex) != h_dir);
bwh = au_dbwh(dentry);
h_path.dentry = wh_dentry;
h_path.mnt = au_sbr_mnt(dir->i_sb, bindex);
err = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path,
dentry);
if (unlikely(err))
goto out;
}
inode = au_new_inode(dentry, /*must_new*/1);
if (!IS_ERR(inode)) {
d_instantiate(dentry, inode);
dir = dentry->d_parent->d_inode; /* dir inode is locked */
IMustLock(dir);
if (au_ibstart(dir) == au_dbstart(dentry))
au_cpup_attr_timesizes(dir);
dir->i_version++;
return 0; /* success */
}
err = PTR_ERR(inode);
if (!wh_dentry)
goto out;
/* revert */
/* dir inode is locked */
wh = au_wh_create(dentry, bwh, wh_dentry->d_parent);
rerr = PTR_ERR(wh);
if (IS_ERR(wh)) {
AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
AuDLNPair(dentry), err, rerr);
err = -EIO;
} else
dput(wh);
out:
return err;
}
static void au_hide(struct dentry *dentry)
{
int err;
AuDbgDentry(dentry);
if (d_is_dir(dentry)) {
/* shrink_dcache_parent(dentry); */
err = au_hide_children(dentry);
if (unlikely(err))
AuIOErr("%pd, failed hiding children, ignored %d\n",
dentry, err);
}
au_do_hide(dentry);
}
static void au_hide(struct dentry *dentry)
{
int err;
struct inode *inode;
AuDbgDentry(dentry);
inode = dentry->d_inode;
if (inode && S_ISDIR(inode->i_mode)) {
/* shrink_dcache_parent(dentry); */
err = au_hide_children(dentry);
if (unlikely(err))
AuIOErr("%.*s, failed hiding children, ignored %d\n",
AuDLNPair(dentry), err);
}
au_do_hide(dentry);
}
/*
* when removing a dir, rename it to a unique temporary whiteout-ed name first
* in order to be revertible and save time for removing many child whiteouts
* under the dir.
* returns 1 when there are too many child whiteout and caller should remove
* them asynchronously. returns 0 when the number of children is enough small to
* remove now or the branch fs is a remote fs.
* otherwise return an error.
*/
static int renwh_and_rmdir(struct dentry *dentry, aufs_bindex_t bindex,
struct au_nhash *whlist, struct inode *dir)
{
int rmdir_later, err, dirwh;
struct dentry *h_dentry;
struct super_block *sb;
struct inode *inode;
sb = dentry->d_sb;
SiMustAnyLock(sb);
h_dentry = au_h_dptr(dentry, bindex);
err = au_whtmp_ren(h_dentry, au_sbr(sb, bindex));
if (unlikely(err))
goto out;
/* stop monitoring */
inode = d_inode(dentry);
au_hn_free(au_hi(inode, bindex));
if (!au_test_fs_remote(h_dentry->d_sb)) {
dirwh = au_sbi(sb)->si_dirwh;
rmdir_later = (dirwh <= 1);
if (!rmdir_later)
rmdir_later = au_nhash_test_longer_wh(whlist, bindex,
dirwh);
if (rmdir_later)
return rmdir_later;
}
err = au_whtmp_rmdir(dir, bindex, h_dentry, whlist);
if (unlikely(err)) {
AuIOErr("rmdir %pd, b%d failed, %d. ignored\n",
h_dentry, bindex, err);
err = 0;
}
out:
AuTraceErr(err);
return err;
}
void au_xigen_inc(struct inode *inode)
{
loff_t pos;
ssize_t sz;
__u32 igen;
struct super_block *sb;
struct au_sbinfo *sbinfo;
sb = inode->i_sb;
AuDebugOn(!au_opt_test(au_mntflags(sb), XINO));
sbinfo = au_sbi(sb);
pos = inode->i_ino;
pos *= sizeof(igen);
igen = inode->i_generation + 1;
sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xigen, &igen,
sizeof(igen), &pos);
if (sz == sizeof(igen))
return; /* success */
if (unlikely(sz >= 0))
AuIOErr("xigen error (%zd)\n", sz);
}
/*
* final procedure of adding a new entry, except link(2).
* remove whiteout, instantiate, copyup the parent dir's times and size
* and update version.
* if it failed, re-create the removed whiteout.
*/
static int epilog(struct inode *dir, aufs_bindex_t bindex,
struct dentry *wh_dentry, struct dentry *dentry)
{
int err, rerr;
aufs_bindex_t bwh;
struct inode *inode, *h_dir;
struct dentry *wh;
struct au_ndx ndx;
struct super_block *sb;
LKTRTrace("wh %p, %.*s\n", wh_dentry, AuDLNPair(dentry));
sb = dentry->d_sb;
bwh = -1;
if (wh_dentry) {
h_dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
IMustLock(h_dir);
AuDebugOn(au_h_iptr(dir, bindex) != h_dir);
bwh = au_dbwh(dentry);
err = au_wh_unlink_dentry(au_hi(dir, bindex), wh_dentry, dentry,
/*dlgt*/0);
if (unlikely(err))
goto out;
}
inode = au_new_inode(dentry, /*must_new*/1);
if (!IS_ERR(inode)) {
d_instantiate(dentry, inode);
dir = dentry->d_parent->d_inode; /* dir inode is locked */
IMustLock(dir);
/* or always cpup dir mtime? */
if (au_ibstart(dir) == au_dbstart(dentry))
au_cpup_attr_timesizes(dir);
dir->i_version++;
return 0; /* success */
}
err = PTR_ERR(inode);
if (!wh_dentry)
goto out;
/* revert */
ndx.flags = 0;
if (au_test_dlgt(au_mntflags(sb)))
au_fset_ndx(ndx.flags, DLGT);
ndx.nfsmnt = au_nfsmnt(sb, bwh);
ndx.nd = NULL;
/* ndx.br = NULL; */
/* dir inode is locked */
wh = au_wh_create(dentry, bwh, wh_dentry->d_parent, &ndx);
rerr = PTR_ERR(wh);
if (IS_ERR(wh)) {
AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
AuDLNPair(dentry), err, rerr);
err = -EIO;
} else
dput(wh);
out:
AuTraceErr(err);
return err;
}
int au_opts_mount(struct super_block *sb, struct au_opts *opts)
{
int err;
unsigned int tmp;
aufs_bindex_t bindex, bend;
struct au_opt *opt;
struct au_opt_xino *opt_xino, xino;
struct au_sbinfo *sbinfo;
struct au_branch *br;
SiMustWriteLock(sb);
err = 0;
opt_xino = NULL;
opt = opts->opt;
while (err >= 0 && opt->type != Opt_tail)
err = au_opt_simple(sb, opt++, opts);
if (err > 0)
err = 0;
else if (unlikely(err < 0))
goto out;
/* disable xino and udba temporary */
sbinfo = au_sbi(sb);
tmp = sbinfo->si_mntflags;
au_opt_clr(sbinfo->si_mntflags, XINO);
au_opt_set_udba(sbinfo->si_mntflags, UDBA_REVAL);
opt = opts->opt;
while (err >= 0 && opt->type != Opt_tail)
err = au_opt_br(sb, opt++, opts);
if (err > 0)
err = 0;
else if (unlikely(err < 0))
goto out;
bend = au_sbend(sb);
if (unlikely(bend < 0)) {
err = -EINVAL;
pr_err("no branches\n");
goto out;
}
if (au_opt_test(tmp, XINO))
au_opt_set(sbinfo->si_mntflags, XINO);
opt = opts->opt;
while (!err && opt->type != Opt_tail)
err = au_opt_xino(sb, opt++, &opt_xino, opts);
if (unlikely(err))
goto out;
err = au_opts_verify(sb, sb->s_flags, tmp);
if (unlikely(err))
goto out;
/* restore xino */
if (au_opt_test(tmp, XINO) && !opt_xino) {
xino.file = au_xino_def(sb);
err = PTR_ERR(xino.file);
if (IS_ERR(xino.file))
goto out;
err = au_xino_set(sb, &xino, /*remount*/0);
fput(xino.file);
if (unlikely(err))
goto out;
}
/* restore udba */
tmp &= AuOptMask_UDBA;
sbinfo->si_mntflags &= ~AuOptMask_UDBA;
sbinfo->si_mntflags |= tmp;
bend = au_sbend(sb);
for (bindex = 0; bindex <= bend; bindex++) {
br = au_sbr(sb, bindex);
err = au_hnotify_reset_br(tmp, br, br->br_perm);
if (unlikely(err))
AuIOErr("hnotify failed on br %d, %d, ignored\n",
bindex, err);
/* go on even if err */
}
if (au_opt_test(tmp, UDBA_HNOTIFY)) {
struct inode *dir = sb->s_root->d_inode;
au_hn_reset(dir, au_hi_flags(dir, /*isdir*/1) & ~AuHi_XINO);
}
out:
return err;
}
static int au_cpdown_dir(struct dentry *dentry, aufs_bindex_t bdst,
struct dentry *h_parent, void *arg)
{
int err, rerr;
aufs_bindex_t bopq, bstart;
struct path h_path;
struct dentry *parent;
struct inode *h_dir, *h_inode, *inode, *dir;
struct au_cpdown_dir_args *args = arg;
bstart = au_dbstart(dentry);
/* dentry is di-locked */
parent = dget_parent(dentry);
dir = parent->d_inode;
h_dir = h_parent->d_inode;
AuDebugOn(h_dir != au_h_iptr(dir, bdst));
IMustLock(h_dir);
err = au_lkup_neg(dentry, bdst);
if (unlikely(err < 0))
goto out;
h_path.dentry = au_h_dptr(dentry, bdst);
h_path.mnt = au_sbr_mnt(dentry->d_sb, bdst);
err = vfsub_sio_mkdir(au_h_iptr(dir, bdst), &h_path,
S_IRWXU | S_IRUGO | S_IXUGO);
if (unlikely(err))
goto out_put;
au_fset_cpdown(args->flags, MADE_DIR);
bopq = au_dbdiropq(dentry);
au_fclr_cpdown(args->flags, WHED);
au_fclr_cpdown(args->flags, DIROPQ);
if (au_dbwh(dentry) == bdst)
au_fset_cpdown(args->flags, WHED);
if (!au_ftest_cpdown(args->flags, PARENT_OPQ) && bopq <= bdst)
au_fset_cpdown(args->flags, PARENT_OPQ);
h_inode = h_path.dentry->d_inode;
mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
if (au_ftest_cpdown(args->flags, WHED)) {
err = au_cpdown_dir_opq(dentry, bdst, args);
if (unlikely(err)) {
mutex_unlock(&h_inode->i_mutex);
goto out_dir;
}
}
err = au_cpdown_attr(&h_path, au_h_dptr(dentry, bstart));
mutex_unlock(&h_inode->i_mutex);
if (unlikely(err))
goto out_opq;
if (au_ftest_cpdown(args->flags, WHED)) {
err = au_cpdown_dir_wh(dentry, h_parent, dir, bdst);
if (unlikely(err))
goto out_opq;
}
inode = dentry->d_inode;
if (au_ibend(inode) < bdst)
au_set_ibend(inode, bdst);
au_set_h_iptr(inode, bdst, au_igrab(h_inode),
au_hi_flags(inode, /*isdir*/1));
goto out; /* success */
/* revert */
out_opq:
if (au_ftest_cpdown(args->flags, DIROPQ)) {
mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
rerr = au_diropq_remove(dentry, bdst);
mutex_unlock(&h_inode->i_mutex);
if (unlikely(rerr)) {
AuIOErr("failed removing diropq for %.*s b%d (%d)\n",
AuDLNPair(dentry), bdst, rerr);
err = -EIO;
goto out;
}
}
out_dir:
if (au_ftest_cpdown(args->flags, MADE_DIR)) {
rerr = vfsub_sio_rmdir(au_h_iptr(dir, bdst), &h_path);
if (unlikely(rerr)) {
AuIOErr("failed removing %.*s b%d (%d)\n",
AuDLNPair(dentry), bdst, rerr);
err = -EIO;
}
}
out_put:
au_set_h_dptr(dentry, bdst, NULL);
if (au_dbend(dentry) == bdst)
au_update_dbend(dentry);
out:
dput(parent);
return err;
}
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;
}
/*
* 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;
}
int aufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
int err, rerr;
aufs_bindex_t bindex;
unsigned char diropq;
struct path h_path;
struct dentry *wh_dentry, *parent, *opq_dentry;
struct mutex *h_mtx;
struct super_block *sb;
struct {
struct au_pin pin;
struct au_dtime dt;
} *a; /* reduce the stack usage */
struct au_wr_dir_args wr_dir_args = {
.force_btgt = -1,
.flags = AuWrDir_ADD_ENTRY | AuWrDir_ISDIR
};
IMustLock(dir);
err = -ENOMEM;
a = kmalloc(sizeof(*a), GFP_NOFS);
if (unlikely(!a))
goto out;
err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
if (unlikely(err))
goto out_free;
err = au_d_may_add(dentry);
if (unlikely(err))
goto out_unlock;
parent = dentry->d_parent; /* dir inode is locked */
di_write_lock_parent(parent);
wh_dentry = lock_hdir_lkup_wh(dentry, &a->dt, /*src_dentry*/NULL,
&a->pin, &wr_dir_args);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out_parent;
sb = dentry->d_sb;
bindex = au_dbstart(dentry);
h_path.dentry = au_h_dptr(dentry, bindex);
h_path.mnt = au_sbr_mnt(sb, bindex);
err = vfsub_mkdir(au_pinned_h_dir(&a->pin), &h_path, mode);
if (unlikely(err))
goto out_unpin;
/* make the dir opaque */
diropq = 0;
h_mtx = &h_path.dentry->d_inode->i_mutex;
if (wh_dentry
|| au_opt_test(au_mntflags(sb), ALWAYS_DIROPQ)) {
mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
opq_dentry = au_diropq_create(dentry, bindex);
mutex_unlock(h_mtx);
err = PTR_ERR(opq_dentry);
if (IS_ERR(opq_dentry))
goto out_dir;
dput(opq_dentry);
diropq = 1;
}
err = epilog(dir, bindex, wh_dentry, dentry);
if (!err) {
inc_nlink(dir);
goto out_unpin; /* success */
}
/* revert */
if (diropq) {
AuLabel(revert opq);
mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
rerr = au_diropq_remove(dentry, bindex);
mutex_unlock(h_mtx);
if (rerr) {
AuIOErr("%.*s reverting diropq failed(%d, %d)\n",
AuDLNPair(dentry), err, rerr);
err = -EIO;
}
}
out_dir:
AuLabel(revert dir);
rerr = vfsub_rmdir(au_pinned_h_dir(&a->pin), &h_path);
if (rerr) {
AuIOErr("%.*s reverting dir failed(%d, %d)\n",
AuDLNPair(dentry), err, rerr);
err = -EIO;
}
au_dtime_revert(&a->dt);
out_unpin:
au_unpin(&a->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_free:
kfree(a);
out:
return err;
}
/*
* when an error happened, remove the created whiteout and revert everything.
*/
static int do_revert(int err, struct inode *dir, aufs_bindex_t bindex,
aufs_bindex_t bwh, struct dentry *wh_dentry,
struct dentry *dentry, struct au_dtime *dt)
{
int rerr;
struct path h_path = {
.dentry = wh_dentry,
.mnt = au_sbr_mnt(dir->i_sb, bindex)
};
rerr = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path, dentry);
if (!rerr) {
au_set_dbwh(dentry, bwh);
au_dtime_revert(dt);
return 0;
}
AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
AuDLNPair(dentry), err, rerr);
return -EIO;
}
/* ---------------------------------------------------------------------- */
int aufs_unlink(struct inode *dir, struct dentry *dentry)
{
int err;
aufs_bindex_t bwh, bindex, bstart;
struct au_dtime dt;
struct au_pin pin;
struct path h_path;
struct inode *inode, *h_dir;
struct dentry *parent, *wh_dentry;
IMustLock(dir);
err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
if (unlikely(err))
goto out;
err = au_d_hashed_positive(dentry);
if (unlikely(err))
goto out_unlock;
inode = dentry->d_inode;
IMustLock(inode);
err = -EISDIR;
if (unlikely(S_ISDIR(inode->i_mode)))
goto out_unlock; /* possible? */
bstart = au_dbstart(dentry);
bwh = au_dbwh(dentry);
bindex = -1;
parent = dentry->d_parent; /* dir inode is locked */
di_write_lock_parent(parent);
wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/0, &bindex, &dt, &pin);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out_parent;
h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
h_path.dentry = au_h_dptr(dentry, bstart);
dget(h_path.dentry);
if (bindex == bstart) {
h_dir = au_pinned_h_dir(&pin);
err = vfsub_unlink(h_dir, &h_path, /*force*/0);
} else {
/* dir inode is locked */
h_dir = wh_dentry->d_parent->d_inode;
IMustLock(h_dir);
err = 0;
}
if (!err) {
vfsub_drop_nlink(inode);
epilog(dir, dentry, bindex);
/* update target timestamps */
if (bindex == bstart) {
vfsub_update_h_iattr(&h_path, /*did*/NULL); /*ignore*/
inode->i_ctime = h_path.dentry->d_inode->i_ctime;
} else
/* todo: this timestamp may be reverted later */
inode->i_ctime = h_dir->i_ctime;
goto out_unpin; /* success */
}
/* revert */
if (wh_dentry) {
int rerr;
rerr = do_revert(err, dir, bindex, bwh, wh_dentry, dentry, &dt);
if (rerr)
err = rerr;
}
out_unpin:
au_unpin(&pin);
dput(wh_dentry);
dput(h_path.dentry);
out_parent:
di_write_unlock(parent);
out_unlock:
aufs_read_unlock(dentry, AuLock_DW);
out:
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;
}
/*
* when an error happened, remove the created whiteout and revert everything.
*/
static int do_revert(int err, struct inode *dir, aufs_bindex_t bindex,
aufs_bindex_t bwh, struct dentry *wh_dentry,
struct dentry *dentry, struct au_dtime *dt)
{
int rerr;
struct path h_path = {
.dentry = wh_dentry,
.mnt = au_sbr_mnt(dir->i_sb, bindex)
};
rerr = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path, dentry);
if (!rerr) {
au_set_dbwh(dentry, bwh);
au_dtime_revert(dt);
return 0;
}
AuIOErr("%pd reverting whiteout failed(%d, %d)\n", dentry, err, rerr);
return -EIO;
}
/* ---------------------------------------------------------------------- */
int aufs_unlink(struct inode *dir, struct dentry *dentry)
{
int err;
aufs_bindex_t bwh, bindex, bstart;
struct inode *inode, *h_dir, *delegated;
struct dentry *parent, *wh_dentry;
/* to reuduce stack size */
struct {
struct au_dtime dt;
struct au_pin pin;
struct path h_path;
} *a;
IMustLock(dir);
err = -ENOMEM;
a = kmalloc(sizeof(*a), GFP_NOFS);
if (unlikely(!a))
goto out;
err = aufs_read_lock(dentry, AuLock_DW | AuLock_GEN);
if (unlikely(err))
goto out_free;
err = au_d_hashed_positive(dentry);
if (unlikely(err))
goto out_unlock;
inode = d_inode(dentry);
IMustLock(inode);
err = -EISDIR;
if (unlikely(d_is_dir(dentry)))
goto out_unlock; /* possible? */
bstart = au_dbstart(dentry);
bwh = au_dbwh(dentry);
bindex = -1;
parent = dentry->d_parent; /* dir inode is locked */
di_write_lock_parent(parent);
wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/0, &bindex, &a->dt,
&a->pin);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out_parent;
a->h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
a->h_path.dentry = au_h_dptr(dentry, bstart);
dget(a->h_path.dentry);
if (bindex == bstart) {
h_dir = au_pinned_h_dir(&a->pin);
delegated = NULL;
err = vfsub_unlink(h_dir, &a->h_path, &delegated, /*force*/0);
if (unlikely(err == -EWOULDBLOCK)) {
pr_warn("cannot retry for NFSv4 delegation"
" for an internal unlink\n");
iput(delegated);
}
} else {
/* dir inode is locked */
h_dir = d_inode(wh_dentry->d_parent);
IMustLock(h_dir);
err = 0;
}
if (!err) {
vfsub_drop_nlink(inode);
epilog(dir, dentry, bindex);
/* update target timestamps */
if (bindex == bstart) {
vfsub_update_h_iattr(&a->h_path, /*did*/NULL);
/*ignore*/
inode->i_ctime = d_inode(a->h_path.dentry)->i_ctime;
} else
/* todo: this timestamp may be reverted later */
inode->i_ctime = h_dir->i_ctime;
goto out_unpin; /* success */
}
/* revert */
if (wh_dentry) {
int rerr;
rerr = do_revert(err, dir, bindex, bwh, wh_dentry, dentry,
&a->dt);
if (rerr)
err = rerr;
}
out_unpin:
au_unpin(&a->pin);
dput(wh_dentry);
dput(a->h_path.dentry);
out_parent:
di_write_unlock(parent);
out_unlock:
aufs_read_unlock(dentry, AuLock_DW);
out_free:
kfree(a);
out:
return err;
}
static int set_inode(struct inode *inode, struct dentry *dentry)
{
int err;
unsigned int flags;
umode_t mode;
aufs_bindex_t bindex, bstart, btail;
unsigned char isdir;
struct dentry *h_dentry;
struct inode *h_inode;
struct au_iinfo *iinfo;
IiMustWriteLock(inode);
err = 0;
isdir = 0;
bstart = au_dbstart(dentry);
h_inode = au_h_dptr(dentry, bstart)->d_inode;
mode = h_inode->i_mode;
switch (mode & S_IFMT) {
case S_IFREG:
btail = au_dbtail(dentry);
inode->i_op = &aufs_iop;
inode->i_fop = &aufs_file_fop;
inode->i_mapping->a_ops = &aufs_aop;
break;
case S_IFDIR:
isdir = 1;
btail = au_dbtaildir(dentry);
inode->i_op = &aufs_dir_iop;
inode->i_fop = &aufs_dir_fop;
break;
case S_IFLNK:
btail = au_dbtail(dentry);
inode->i_op = &aufs_symlink_iop;
break;
case S_IFBLK:
case S_IFCHR:
case S_IFIFO:
case S_IFSOCK:
btail = au_dbtail(dentry);
inode->i_op = &aufs_iop;
au_init_special_fop(inode, mode, h_inode->i_rdev);
break;
default:
AuIOErr("Unknown file type 0%o\n", mode);
err = -EIO;
goto out;
}
/* do not set inotify for whiteouted dirs (SHWH mode) */
flags = au_hi_flags(inode, isdir);
if (au_opt_test(au_mntflags(dentry->d_sb), SHWH)
&& au_ftest_hi(flags, HINOTIFY)
&& dentry->d_name.len > AUFS_WH_PFX_LEN
&& !memcmp(dentry->d_name.name, AUFS_WH_PFX, AUFS_WH_PFX_LEN))
au_fclr_hi(flags, HINOTIFY);
iinfo = au_ii(inode);
iinfo->ii_bstart = bstart;
iinfo->ii_bend = btail;
for (bindex = bstart; bindex <= btail; bindex++) {
h_dentry = au_h_dptr(dentry, bindex);
if (h_dentry)
au_set_h_iptr(inode, bindex,
au_igrab(h_dentry->d_inode), flags);
}
au_cpup_attr_all(inode, /*force*/1);
out:
return err;
}
int aufs_link(struct dentry *src_dentry, struct inode *dir,
struct dentry *dentry)
{
int err, rerr;
struct au_dtime dt;
struct au_link_args *a;
struct dentry *wh_dentry, *h_src_dentry;
struct inode *inode;
struct super_block *sb;
struct au_wr_dir_args wr_dir_args = {
/* .force_btgt = -1, */
.flags = AuWrDir_ADD_ENTRY
};
IMustLock(dir);
inode = src_dentry->d_inode;
IMustLock(inode);
err = -ENOMEM;
a = kzalloc(sizeof(*a), GFP_NOFS);
if (unlikely(!a))
goto out;
a->parent = dentry->d_parent; /* dir inode is locked */
err = aufs_read_and_write_lock2(dentry, src_dentry,
AuLock_NOPLM | AuLock_GEN);
if (unlikely(err))
goto out_kfree;
err = au_d_hashed_positive(src_dentry);
if (unlikely(err))
goto out_unlock;
err = au_d_may_add(dentry);
if (unlikely(err))
goto out_unlock;
a->src_parent = dget_parent(src_dentry);
wr_dir_args.force_btgt = au_ibstart(inode);
di_write_lock_parent(a->parent);
wr_dir_args.force_btgt = au_wbr(dentry, wr_dir_args.force_btgt);
wh_dentry = lock_hdir_lkup_wh(dentry, &dt, src_dentry, &a->pin,
&wr_dir_args);
err = PTR_ERR(wh_dentry);
if (IS_ERR(wh_dentry))
goto out_parent;
err = 0;
sb = dentry->d_sb;
a->bdst = au_dbstart(dentry);
a->h_path.dentry = au_h_dptr(dentry, a->bdst);
a->h_path.mnt = au_sbr_mnt(sb, a->bdst);
a->bsrc = au_ibstart(inode);
h_src_dentry = au_h_d_alias(src_dentry, a->bsrc);
if (!h_src_dentry) {
a->bsrc = au_dbstart(src_dentry);
h_src_dentry = au_h_d_alias(src_dentry, a->bsrc);
AuDebugOn(!h_src_dentry);
} else if (IS_ERR(h_src_dentry))
goto out_parent;
if (au_opt_test(au_mntflags(sb), PLINK)) {
if (a->bdst < a->bsrc
/* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */)
err = au_cpup_or_link(src_dentry, a);
else
err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
&a->h_path);
dput(h_src_dentry);
} else {
/*
* copyup src_dentry to the branch we process,
* and then link(2) to it.
*/
dput(h_src_dentry);
if (a->bdst < a->bsrc
/* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */) {
au_unpin(&a->pin);
di_write_unlock(a->parent);
err = au_cpup_before_link(src_dentry, a);
di_write_lock_parent(a->parent);
if (!err)
err = au_pin(&a->pin, dentry, a->bdst,
au_opt_udba(sb),
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
if (unlikely(err))
goto out_wh;
}
if (!err) {
h_src_dentry = au_h_dptr(src_dentry, a->bdst);
err = -ENOENT;
if (h_src_dentry && h_src_dentry->d_inode)
err = vfsub_link(h_src_dentry,
au_pinned_h_dir(&a->pin),
&a->h_path);
}
}
if (unlikely(err))
goto out_unpin;
if (wh_dentry) {
a->h_path.dentry = wh_dentry;
err = au_wh_unlink_dentry(au_pinned_h_dir(&a->pin), &a->h_path,
dentry);
if (unlikely(err))
goto out_revert;
}
dir->i_version++;
if (au_ibstart(dir) == au_dbstart(dentry))
au_cpup_attr_timesizes(dir);
inc_nlink(inode);
inode->i_ctime = dir->i_ctime;
d_instantiate(dentry, au_igrab(inode));
if (d_unhashed(a->h_path.dentry))
/* some filesystem calls d_drop() */
d_drop(dentry);
goto out_unpin; /* success */
out_revert:
rerr = vfsub_unlink(au_pinned_h_dir(&a->pin), &a->h_path, /*force*/0);
if (unlikely(rerr)) {
AuIOErr("%.*s reverting failed(%d, %d)\n",
AuDLNPair(dentry), err, rerr);
err = -EIO;
}
au_dtime_revert(&dt);
out_unpin:
au_unpin(&a->pin);
out_wh:
dput(wh_dentry);
out_parent:
di_write_unlock(a->parent);
dput(a->src_parent);
out_unlock:
if (unlikely(err)) {
au_update_dbstart(dentry);
d_drop(dentry);
}
aufs_read_and_write_unlock2(dentry, src_dentry);
out_kfree:
kfree(a);
out:
return err;
}