/usr/src/aufs-4.9+20161219/fs/aufs/super.c is in aufs-dkms 4.9+20161219-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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* Copyright (C) 2005-2016 Junjiro R. Okajima
*
* This program, aufs is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* mount and super_block operations
*/
#include <linux/mm.h>
#include <linux/seq_file.h>
#include <linux/statfs.h>
#include <linux/vmalloc.h>
#include "aufs.h"
/*
* super_operations
*/
static struct inode *aufs_alloc_inode(struct super_block *sb __maybe_unused)
{
struct au_icntnr *c;
c = au_cache_alloc_icntnr();
if (c) {
au_icntnr_init(c);
c->vfs_inode.i_version = 1; /* sigen(sb); */
c->iinfo.ii_hinode = NULL;
return &c->vfs_inode;
}
return NULL;
}
static void aufs_destroy_inode_cb(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
au_cache_dfree_icntnr(container_of(inode, struct au_icntnr, vfs_inode));
}
static void aufs_destroy_inode(struct inode *inode)
{
if (!au_is_bad_inode(inode))
au_iinfo_fin(inode);
call_rcu(&inode->i_rcu, aufs_destroy_inode_cb);
}
struct inode *au_iget_locked(struct super_block *sb, ino_t ino)
{
struct inode *inode;
int err;
inode = iget_locked(sb, ino);
if (unlikely(!inode)) {
inode = ERR_PTR(-ENOMEM);
goto out;
}
if (!(inode->i_state & I_NEW))
goto out;
err = au_xigen_new(inode);
if (!err)
err = au_iinfo_init(inode);
if (!err)
inode->i_version++;
else {
iget_failed(inode);
inode = ERR_PTR(err);
}
out:
/* never return NULL */
AuDebugOn(!inode);
AuTraceErrPtr(inode);
return inode;
}
/* lock free root dinfo */
static int au_show_brs(struct seq_file *seq, struct super_block *sb)
{
int err;
aufs_bindex_t bindex, bbot;
struct path path;
struct au_hdentry *hdp;
struct au_branch *br;
au_br_perm_str_t perm;
err = 0;
bbot = au_sbbot(sb);
bindex = 0;
hdp = au_hdentry(au_di(sb->s_root), bindex);
for (; !err && bindex <= bbot; bindex++, hdp++) {
br = au_sbr(sb, bindex);
path.mnt = au_br_mnt(br);
path.dentry = hdp->hd_dentry;
err = au_seq_path(seq, &path);
if (!err) {
au_optstr_br_perm(&perm, br->br_perm);
seq_printf(seq, "=%s", perm.a);
if (bindex != bbot)
seq_putc(seq, ':');
}
}
if (unlikely(err || seq_has_overflowed(seq)))
err = -E2BIG;
return err;
}
static void au_gen_fmt(char *fmt, int len __maybe_unused, const char *pat,
const char *append)
{
char *p;
p = fmt;
while (*pat != ':')
*p++ = *pat++;
*p++ = *pat++;
strcpy(p, append);
AuDebugOn(strlen(fmt) >= len);
}
static void au_show_wbr_create(struct seq_file *m, int v,
struct au_sbinfo *sbinfo)
{
const char *pat;
char fmt[32];
struct au_wbr_mfs *mfs;
AuRwMustAnyLock(&sbinfo->si_rwsem);
seq_puts(m, ",create=");
pat = au_optstr_wbr_create(v);
mfs = &sbinfo->si_wbr_mfs;
switch (v) {
case AuWbrCreate_TDP:
case AuWbrCreate_RR:
case AuWbrCreate_MFS:
case AuWbrCreate_PMFS:
seq_puts(m, pat);
break;
case AuWbrCreate_MFSRR:
case AuWbrCreate_TDMFS:
case AuWbrCreate_PMFSRR:
au_gen_fmt(fmt, sizeof(fmt), pat, "%llu");
seq_printf(m, fmt, mfs->mfsrr_watermark);
break;
case AuWbrCreate_MFSV:
case AuWbrCreate_PMFSV:
au_gen_fmt(fmt, sizeof(fmt), pat, "%lu");
seq_printf(m, fmt,
jiffies_to_msecs(mfs->mfs_expire)
/ MSEC_PER_SEC);
break;
case AuWbrCreate_MFSRRV:
case AuWbrCreate_TDMFSV:
case AuWbrCreate_PMFSRRV:
au_gen_fmt(fmt, sizeof(fmt), pat, "%llu:%lu");
seq_printf(m, fmt, mfs->mfsrr_watermark,
jiffies_to_msecs(mfs->mfs_expire) / MSEC_PER_SEC);
break;
default:
BUG();
}
}
static int au_show_xino(struct seq_file *seq, struct super_block *sb)
{
#ifdef CONFIG_SYSFS
return 0;
#else
int err;
const int len = sizeof(AUFS_XINO_FNAME) - 1;
aufs_bindex_t bindex, brid;
struct qstr *name;
struct file *f;
struct dentry *d, *h_root;
AuRwMustAnyLock(&sbinfo->si_rwsem);
err = 0;
f = au_sbi(sb)->si_xib;
if (!f)
goto out;
/* stop printing the default xino path on the first writable branch */
h_root = NULL;
brid = au_xino_brid(sb);
if (brid >= 0) {
bindex = au_br_index(sb, brid);
h_root = au_hdentry(au_di(sb->s_root), bindex)->hd_dentry;
}
d = f->f_path.dentry;
name = &d->d_name;
/* safe ->d_parent because the file is unlinked */
if (d->d_parent == h_root
&& name->len == len
&& !memcmp(name->name, AUFS_XINO_FNAME, len))
goto out;
seq_puts(seq, ",xino=");
err = au_xino_path(seq, f);
out:
return err;
#endif
}
/* seq_file will re-call me in case of too long string */
static int aufs_show_options(struct seq_file *m, struct dentry *dentry)
{
int err;
unsigned int mnt_flags, v;
struct super_block *sb;
struct au_sbinfo *sbinfo;
#define AuBool(name, str) do { \
v = au_opt_test(mnt_flags, name); \
if (v != au_opt_test(AuOpt_Def, name)) \
seq_printf(m, ",%s" #str, v ? "" : "no"); \
} while (0)
#define AuStr(name, str) do { \
v = mnt_flags & AuOptMask_##name; \
if (v != (AuOpt_Def & AuOptMask_##name)) \
seq_printf(m, "," #str "=%s", au_optstr_##str(v)); \
} while (0)
#define AuUInt(name, str, val) do { \
if (val != AUFS_##name##_DEF) \
seq_printf(m, "," #str "=%u", val); \
} while (0)
sb = dentry->d_sb;
if (sb->s_flags & MS_POSIXACL)
seq_puts(m, ",acl");
/* lock free root dinfo */
si_noflush_read_lock(sb);
sbinfo = au_sbi(sb);
seq_printf(m, ",si=%lx", sysaufs_si_id(sbinfo));
mnt_flags = au_mntflags(sb);
if (au_opt_test(mnt_flags, XINO)) {
err = au_show_xino(m, sb);
if (unlikely(err))
goto out;
} else
seq_puts(m, ",noxino");
AuBool(TRUNC_XINO, trunc_xino);
AuStr(UDBA, udba);
AuBool(SHWH, shwh);
AuBool(PLINK, plink);
AuBool(DIO, dio);
AuBool(DIRPERM1, dirperm1);
v = sbinfo->si_wbr_create;
if (v != AuWbrCreate_Def)
au_show_wbr_create(m, v, sbinfo);
v = sbinfo->si_wbr_copyup;
if (v != AuWbrCopyup_Def)
seq_printf(m, ",cpup=%s", au_optstr_wbr_copyup(v));
v = au_opt_test(mnt_flags, ALWAYS_DIROPQ);
if (v != au_opt_test(AuOpt_Def, ALWAYS_DIROPQ))
seq_printf(m, ",diropq=%c", v ? 'a' : 'w');
AuUInt(DIRWH, dirwh, sbinfo->si_dirwh);
v = jiffies_to_msecs(sbinfo->si_rdcache) / MSEC_PER_SEC;
AuUInt(RDCACHE, rdcache, v);
AuUInt(RDBLK, rdblk, sbinfo->si_rdblk);
AuUInt(RDHASH, rdhash, sbinfo->si_rdhash);
au_fhsm_show(m, sbinfo);
AuBool(SUM, sum);
/* AuBool(SUM_W, wsum); */
AuBool(WARN_PERM, warn_perm);
AuBool(VERBOSE, verbose);
out:
/* be sure to print "br:" last */
if (!sysaufs_brs) {
seq_puts(m, ",br:");
au_show_brs(m, sb);
}
si_read_unlock(sb);
return 0;
#undef AuBool
#undef AuStr
#undef AuUInt
}
/* ---------------------------------------------------------------------- */
/* sum mode which returns the summation for statfs(2) */
static u64 au_add_till_max(u64 a, u64 b)
{
u64 old;
old = a;
a += b;
if (old <= a)
return a;
return ULLONG_MAX;
}
static u64 au_mul_till_max(u64 a, long mul)
{
u64 old;
old = a;
a *= mul;
if (old <= a)
return a;
return ULLONG_MAX;
}
static int au_statfs_sum(struct super_block *sb, struct kstatfs *buf)
{
int err;
long bsize, factor;
u64 blocks, bfree, bavail, files, ffree;
aufs_bindex_t bbot, bindex, i;
unsigned char shared;
struct path h_path;
struct super_block *h_sb;
err = 0;
bsize = LONG_MAX;
files = 0;
ffree = 0;
blocks = 0;
bfree = 0;
bavail = 0;
bbot = au_sbbot(sb);
for (bindex = 0; bindex <= bbot; bindex++) {
h_path.mnt = au_sbr_mnt(sb, bindex);
h_sb = h_path.mnt->mnt_sb;
shared = 0;
for (i = 0; !shared && i < bindex; i++)
shared = (au_sbr_sb(sb, i) == h_sb);
if (shared)
continue;
/* sb->s_root for NFS is unreliable */
h_path.dentry = h_path.mnt->mnt_root;
err = vfs_statfs(&h_path, buf);
if (unlikely(err))
goto out;
if (bsize > buf->f_bsize) {
/*
* we will reduce bsize, so we have to expand blocks
* etc. to match them again
*/
factor = (bsize / buf->f_bsize);
blocks = au_mul_till_max(blocks, factor);
bfree = au_mul_till_max(bfree, factor);
bavail = au_mul_till_max(bavail, factor);
bsize = buf->f_bsize;
}
factor = (buf->f_bsize / bsize);
blocks = au_add_till_max(blocks,
au_mul_till_max(buf->f_blocks, factor));
bfree = au_add_till_max(bfree,
au_mul_till_max(buf->f_bfree, factor));
bavail = au_add_till_max(bavail,
au_mul_till_max(buf->f_bavail, factor));
files = au_add_till_max(files, buf->f_files);
ffree = au_add_till_max(ffree, buf->f_ffree);
}
buf->f_bsize = bsize;
buf->f_blocks = blocks;
buf->f_bfree = bfree;
buf->f_bavail = bavail;
buf->f_files = files;
buf->f_ffree = ffree;
buf->f_frsize = 0;
out:
return err;
}
static int aufs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int err;
struct path h_path;
struct super_block *sb;
/* lock free root dinfo */
sb = dentry->d_sb;
si_noflush_read_lock(sb);
if (!au_opt_test(au_mntflags(sb), SUM)) {
/* sb->s_root for NFS is unreliable */
h_path.mnt = au_sbr_mnt(sb, 0);
h_path.dentry = h_path.mnt->mnt_root;
err = vfs_statfs(&h_path, buf);
} else
err = au_statfs_sum(sb, buf);
si_read_unlock(sb);
if (!err) {
buf->f_type = AUFS_SUPER_MAGIC;
buf->f_namelen = AUFS_MAX_NAMELEN;
memset(&buf->f_fsid, 0, sizeof(buf->f_fsid));
}
/* buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1; */
return err;
}
/* ---------------------------------------------------------------------- */
static int aufs_sync_fs(struct super_block *sb, int wait)
{
int err, e;
aufs_bindex_t bbot, bindex;
struct au_branch *br;
struct super_block *h_sb;
err = 0;
si_noflush_read_lock(sb);
bbot = au_sbbot(sb);
for (bindex = 0; bindex <= bbot; bindex++) {
br = au_sbr(sb, bindex);
if (!au_br_writable(br->br_perm))
continue;
h_sb = au_sbr_sb(sb, bindex);
if (h_sb->s_op->sync_fs) {
e = h_sb->s_op->sync_fs(h_sb, wait);
if (unlikely(e && !err))
err = e;
/* go on even if an error happens */
}
}
si_read_unlock(sb);
return err;
}
/* ---------------------------------------------------------------------- */
/* final actions when unmounting a file system */
static void aufs_put_super(struct super_block *sb)
{
struct au_sbinfo *sbinfo;
sbinfo = au_sbi(sb);
if (!sbinfo)
return;
dbgaufs_si_fin(sbinfo);
kobject_put(&sbinfo->si_kobj);
}
/* ---------------------------------------------------------------------- */
void *au_array_alloc(unsigned long long *hint, au_arraycb_t cb,
struct super_block *sb, void *arg)
{
void *array;
unsigned long long n, sz;
array = NULL;
n = 0;
if (!*hint)
goto out;
if (*hint > ULLONG_MAX / sizeof(array)) {
array = ERR_PTR(-EMFILE);
pr_err("hint %llu\n", *hint);
goto out;
}
sz = sizeof(array) * *hint;
array = kzalloc(sz, GFP_NOFS);
if (unlikely(!array))
array = vzalloc(sz);
if (unlikely(!array)) {
array = ERR_PTR(-ENOMEM);
goto out;
}
n = cb(sb, array, *hint, arg);
AuDebugOn(n > *hint);
out:
*hint = n;
return array;
}
static unsigned long long au_iarray_cb(struct super_block *sb, void *a,
unsigned long long max __maybe_unused,
void *arg)
{
unsigned long long n;
struct inode **p, *inode;
struct list_head *head;
n = 0;
p = a;
head = arg;
spin_lock(&sb->s_inode_list_lock);
list_for_each_entry(inode, head, i_sb_list) {
if (!au_is_bad_inode(inode)
&& au_ii(inode)->ii_btop >= 0) {
spin_lock(&inode->i_lock);
if (atomic_read(&inode->i_count)) {
au_igrab(inode);
*p++ = inode;
n++;
AuDebugOn(n > max);
}
spin_unlock(&inode->i_lock);
}
}
spin_unlock(&sb->s_inode_list_lock);
return n;
}
struct inode **au_iarray_alloc(struct super_block *sb, unsigned long long *max)
{
*max = au_ninodes(sb);
return au_array_alloc(max, au_iarray_cb, sb, &sb->s_inodes);
}
void au_iarray_free(struct inode **a, unsigned long long max)
{
unsigned long long ull;
for (ull = 0; ull < max; ull++)
iput(a[ull]);
kvfree(a);
}
/* ---------------------------------------------------------------------- */
/*
* refresh dentry and inode at remount time.
*/
/* todo: consolidate with simple_reval_dpath() and au_reval_for_attr() */
static int au_do_refresh(struct dentry *dentry, unsigned int dir_flags,
struct dentry *parent)
{
int err;
di_write_lock_child(dentry);
di_read_lock_parent(parent, AuLock_IR);
err = au_refresh_dentry(dentry, parent);
if (!err && dir_flags)
au_hn_reset(d_inode(dentry), dir_flags);
di_read_unlock(parent, AuLock_IR);
di_write_unlock(dentry);
return err;
}
static int au_do_refresh_d(struct dentry *dentry, unsigned int sigen,
struct au_sbinfo *sbinfo,
const unsigned int dir_flags, unsigned int do_idop)
{
int err;
struct dentry *parent;
err = 0;
parent = dget_parent(dentry);
if (!au_digen_test(parent, sigen) && au_digen_test(dentry, sigen)) {
if (d_really_is_positive(dentry)) {
if (!d_is_dir(dentry))
err = au_do_refresh(dentry, /*dir_flags*/0,
parent);
else {
err = au_do_refresh(dentry, dir_flags, parent);
if (unlikely(err))
au_fset_si(sbinfo, FAILED_REFRESH_DIR);
}
} else
err = au_do_refresh(dentry, /*dir_flags*/0, parent);
AuDbgDentry(dentry);
}
dput(parent);
if (!err) {
if (do_idop)
au_refresh_dop(dentry, /*force_reval*/0);
} else
au_refresh_dop(dentry, /*force_reval*/1);
AuTraceErr(err);
return err;
}
static int au_refresh_d(struct super_block *sb, unsigned int do_idop)
{
int err, i, j, ndentry, e;
unsigned int sigen;
struct au_dcsub_pages dpages;
struct au_dpage *dpage;
struct dentry **dentries, *d;
struct au_sbinfo *sbinfo;
struct dentry *root = sb->s_root;
const unsigned int dir_flags = au_hi_flags(d_inode(root), /*isdir*/1);
if (do_idop)
au_refresh_dop(root, /*force_reval*/0);
err = au_dpages_init(&dpages, GFP_NOFS);
if (unlikely(err))
goto out;
err = au_dcsub_pages(&dpages, root, NULL, NULL);
if (unlikely(err))
goto out_dpages;
sigen = au_sigen(sb);
sbinfo = au_sbi(sb);
for (i = 0; i < dpages.ndpage; i++) {
dpage = dpages.dpages + i;
dentries = dpage->dentries;
ndentry = dpage->ndentry;
for (j = 0; j < ndentry; j++) {
d = dentries[j];
e = au_do_refresh_d(d, sigen, sbinfo, dir_flags,
do_idop);
if (unlikely(e && !err))
err = e;
/* go on even err */
}
}
out_dpages:
au_dpages_free(&dpages);
out:
return err;
}
static int au_refresh_i(struct super_block *sb, unsigned int do_idop)
{
int err, e;
unsigned int sigen;
unsigned long long max, ull;
struct inode *inode, **array;
array = au_iarray_alloc(sb, &max);
err = PTR_ERR(array);
if (IS_ERR(array))
goto out;
err = 0;
sigen = au_sigen(sb);
for (ull = 0; ull < max; ull++) {
inode = array[ull];
if (unlikely(!inode))
break;
e = 0;
ii_write_lock_child(inode);
if (au_iigen(inode, NULL) != sigen) {
e = au_refresh_hinode_self(inode);
if (unlikely(e)) {
au_refresh_iop(inode, /*force_getattr*/1);
pr_err("error %d, i%lu\n", e, inode->i_ino);
if (!err)
err = e;
/* go on even if err */
}
}
if (!e && do_idop)
au_refresh_iop(inode, /*force_getattr*/0);
ii_write_unlock(inode);
}
au_iarray_free(array, max);
out:
return err;
}
static void au_remount_refresh(struct super_block *sb, unsigned int do_idop)
{
int err, e;
unsigned int udba;
aufs_bindex_t bindex, bbot;
struct dentry *root;
struct inode *inode;
struct au_branch *br;
struct au_sbinfo *sbi;
au_sigen_inc(sb);
sbi = au_sbi(sb);
au_fclr_si(sbi, FAILED_REFRESH_DIR);
root = sb->s_root;
DiMustNoWaiters(root);
inode = d_inode(root);
IiMustNoWaiters(inode);
udba = au_opt_udba(sb);
bbot = au_sbbot(sb);
for (bindex = 0; bindex <= bbot; bindex++) {
br = au_sbr(sb, bindex);
err = au_hnotify_reset_br(udba, br, br->br_perm);
if (unlikely(err))
AuIOErr("hnotify failed on br %d, %d, ignored\n",
bindex, err);
/* go on even if err */
}
au_hn_reset(inode, au_hi_flags(inode, /*isdir*/1));
if (do_idop) {
if (au_ftest_si(sbi, NO_DREVAL)) {
AuDebugOn(sb->s_d_op == &aufs_dop_noreval);
sb->s_d_op = &aufs_dop_noreval;
AuDebugOn(sbi->si_iop_array == aufs_iop_nogetattr);
sbi->si_iop_array = aufs_iop_nogetattr;
} else {
AuDebugOn(sb->s_d_op == &aufs_dop);
sb->s_d_op = &aufs_dop;
AuDebugOn(sbi->si_iop_array == aufs_iop);
sbi->si_iop_array = aufs_iop;
}
pr_info("reset to %pf and %pf\n",
sb->s_d_op, sbi->si_iop_array);
}
di_write_unlock(root);
err = au_refresh_d(sb, do_idop);
e = au_refresh_i(sb, do_idop);
if (unlikely(e && !err))
err = e;
/* aufs_write_lock() calls ..._child() */
di_write_lock_child(root);
au_cpup_attr_all(inode, /*force*/1);
if (unlikely(err))
AuIOErr("refresh failed, ignored, %d\n", err);
}
/* stop extra interpretation of errno in mount(8), and strange error messages */
static int cvt_err(int err)
{
AuTraceErr(err);
switch (err) {
case -ENOENT:
case -ENOTDIR:
case -EEXIST:
case -EIO:
err = -EINVAL;
}
return err;
}
static int aufs_remount_fs(struct super_block *sb, int *flags, char *data)
{
int err, do_dx;
unsigned int mntflags;
struct au_opts opts = {
.opt = NULL
};
struct dentry *root;
struct inode *inode;
struct au_sbinfo *sbinfo;
err = 0;
root = sb->s_root;
if (!data || !*data) {
err = si_write_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
if (!err) {
di_write_lock_child(root);
err = au_opts_verify(sb, *flags, /*pending*/0);
aufs_write_unlock(root);
}
goto out;
}
err = -ENOMEM;
opts.opt = (void *)__get_free_page(GFP_NOFS);
if (unlikely(!opts.opt))
goto out;
opts.max_opt = PAGE_SIZE / sizeof(*opts.opt);
opts.flags = AuOpts_REMOUNT;
opts.sb_flags = *flags;
/* parse it before aufs lock */
err = au_opts_parse(sb, data, &opts);
if (unlikely(err))
goto out_opts;
sbinfo = au_sbi(sb);
inode = d_inode(root);
inode_lock(inode);
err = si_write_lock(sb, AuLock_FLUSH | AuLock_NOPLM);
if (unlikely(err))
goto out_mtx;
di_write_lock_child(root);
/* au_opts_remount() may return an error */
err = au_opts_remount(sb, &opts);
au_opts_free(&opts);
if (au_ftest_opts(opts.flags, REFRESH))
au_remount_refresh(sb, au_ftest_opts(opts.flags, REFRESH_IDOP));
if (au_ftest_opts(opts.flags, REFRESH_DYAOP)) {
mntflags = au_mntflags(sb);
do_dx = !!au_opt_test(mntflags, DIO);
au_dy_arefresh(do_dx);
}
au_fhsm_wrote_all(sb, /*force*/1); /* ?? */
aufs_write_unlock(root);
out_mtx:
inode_unlock(inode);
out_opts:
au_delayed_free_page((unsigned long)opts.opt);
out:
err = cvt_err(err);
AuTraceErr(err);
return err;
}
static const struct super_operations aufs_sop = {
.alloc_inode = aufs_alloc_inode,
.destroy_inode = aufs_destroy_inode,
/* always deleting, no clearing */
.drop_inode = generic_delete_inode,
.show_options = aufs_show_options,
.statfs = aufs_statfs,
.put_super = aufs_put_super,
.sync_fs = aufs_sync_fs,
.remount_fs = aufs_remount_fs
};
/* ---------------------------------------------------------------------- */
static int alloc_root(struct super_block *sb)
{
int err;
struct inode *inode;
struct dentry *root;
err = -ENOMEM;
inode = au_iget_locked(sb, AUFS_ROOT_INO);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out;
inode->i_op = aufs_iop + AuIop_DIR; /* with getattr by default */
inode->i_fop = &aufs_dir_fop;
inode->i_mode = S_IFDIR;
set_nlink(inode, 2);
unlock_new_inode(inode);
root = d_make_root(inode);
if (unlikely(!root))
goto out;
err = PTR_ERR(root);
if (IS_ERR(root))
goto out;
err = au_di_init(root);
if (!err) {
sb->s_root = root;
return 0; /* success */
}
dput(root);
out:
return err;
}
static int aufs_fill_super(struct super_block *sb, void *raw_data,
int silent __maybe_unused)
{
int err;
struct au_opts opts = {
.opt = NULL
};
struct au_sbinfo *sbinfo;
struct dentry *root;
struct inode *inode;
char *arg = raw_data;
if (unlikely(!arg || !*arg)) {
err = -EINVAL;
pr_err("no arg\n");
goto out;
}
err = -ENOMEM;
opts.opt = (void *)__get_free_page(GFP_NOFS);
if (unlikely(!opts.opt))
goto out;
opts.max_opt = PAGE_SIZE / sizeof(*opts.opt);
opts.sb_flags = sb->s_flags;
err = au_si_alloc(sb);
if (unlikely(err))
goto out_opts;
sbinfo = au_sbi(sb);
/* all timestamps always follow the ones on the branch */
sb->s_flags |= MS_NOATIME | MS_NODIRATIME;
sb->s_op = &aufs_sop;
sb->s_d_op = &aufs_dop;
sb->s_magic = AUFS_SUPER_MAGIC;
sb->s_maxbytes = 0;
sb->s_stack_depth = 1;
au_export_init(sb);
au_xattr_init(sb);
err = alloc_root(sb);
if (unlikely(err)) {
si_write_unlock(sb);
goto out_info;
}
root = sb->s_root;
inode = d_inode(root);
/*
* actually we can parse options regardless aufs lock here.
* but at remount time, parsing must be done before aufs lock.
* so we follow the same rule.
*/
ii_write_lock_parent(inode);
aufs_write_unlock(root);
err = au_opts_parse(sb, arg, &opts);
if (unlikely(err))
goto out_root;
/* lock vfs_inode first, then aufs. */
inode_lock(inode);
aufs_write_lock(root);
err = au_opts_mount(sb, &opts);
au_opts_free(&opts);
if (!err && au_ftest_si(sbinfo, NO_DREVAL)) {
sb->s_d_op = &aufs_dop_noreval;
pr_info("%pf\n", sb->s_d_op);
au_refresh_dop(root, /*force_reval*/0);
sbinfo->si_iop_array = aufs_iop_nogetattr;
au_refresh_iop(inode, /*force_getattr*/0);
}
aufs_write_unlock(root);
inode_unlock(inode);
if (!err)
goto out_opts; /* success */
out_root:
dput(root);
sb->s_root = NULL;
out_info:
dbgaufs_si_fin(sbinfo);
kobject_put(&sbinfo->si_kobj);
sb->s_fs_info = NULL;
out_opts:
au_delayed_free_page((unsigned long)opts.opt);
out:
AuTraceErr(err);
err = cvt_err(err);
AuTraceErr(err);
return err;
}
/* ---------------------------------------------------------------------- */
static struct dentry *aufs_mount(struct file_system_type *fs_type, int flags,
const char *dev_name __maybe_unused,
void *raw_data)
{
struct dentry *root;
struct super_block *sb;
/* all timestamps always follow the ones on the branch */
/* mnt->mnt_flags |= MNT_NOATIME | MNT_NODIRATIME; */
root = mount_nodev(fs_type, flags, raw_data, aufs_fill_super);
if (IS_ERR(root))
goto out;
sb = root->d_sb;
si_write_lock(sb, !AuLock_FLUSH);
sysaufs_brs_add(sb, 0);
si_write_unlock(sb);
au_sbilist_add(sb);
out:
return root;
}
static void aufs_kill_sb(struct super_block *sb)
{
struct au_sbinfo *sbinfo;
sbinfo = au_sbi(sb);
if (sbinfo) {
au_sbilist_del(sb);
aufs_write_lock(sb->s_root);
au_fhsm_fin(sb);
if (sbinfo->si_wbr_create_ops->fin)
sbinfo->si_wbr_create_ops->fin(sb);
if (au_opt_test(sbinfo->si_mntflags, UDBA_HNOTIFY)) {
au_opt_set_udba(sbinfo->si_mntflags, UDBA_NONE);
au_remount_refresh(sb, /*do_idop*/0);
}
if (au_opt_test(sbinfo->si_mntflags, PLINK))
au_plink_put(sb, /*verbose*/1);
au_xino_clr(sb);
sbinfo->si_sb = NULL;
aufs_write_unlock(sb->s_root);
au_nwt_flush(&sbinfo->si_nowait);
}
kill_anon_super(sb);
}
struct file_system_type aufs_fs_type = {
.name = AUFS_FSTYPE,
/* a race between rename and others */
.fs_flags = FS_RENAME_DOES_D_MOVE,
.mount = aufs_mount,
.kill_sb = aufs_kill_sb,
/* no need to __module_get() and module_put(). */
.owner = THIS_MODULE,
};
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