/* common function to regular file and dir */
int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
int wlock)
{
int err;
unsigned int sigen, figen;
aufs_bindex_t bstart;
unsigned char pseudo_link;
struct dentry *dentry;
struct inode *inode;
err = 0;
dentry = file->f_dentry;
inode = dentry->d_inode;
AuDebugOn(au_special_file(inode->i_mode));
sigen = au_sigen(dentry->d_sb);
fi_write_lock(file);
figen = au_figen(file);
di_write_lock_child(dentry);
bstart = au_dbstart(dentry);
pseudo_link = (bstart != au_ibstart(inode));
if (sigen == figen && !pseudo_link && au_fbstart(file) == bstart) {
if (!wlock) {
di_downgrade_lock(dentry, AuLock_IR);
fi_downgrade_lock(file);
}
goto out; /* success */
}
AuDbg("sigen %d, figen %d\n", sigen, figen);
if (sigen != au_digen(dentry)
|| sigen != au_iigen(inode)) {
err = au_reval_dpath(dentry, sigen);
if (unlikely(err < 0))
goto out;
AuDebugOn(au_digen(dentry) != sigen
|| au_iigen(inode) != sigen);
}
err = refresh_file(file, reopen);
if (!err) {
if (!wlock) {
di_downgrade_lock(dentry, AuLock_IR);
fi_downgrade_lock(file);
}
} else {
di_write_unlock(dentry);
fi_write_unlock(file);
}
out:
return err;
}
void au_finfo_fin(struct file *file)
{
struct au_finfo *finfo;
aufs_bindex_t bindex, bend;
fi_write_lock(file);
bend = au_fbend(file);
bindex = au_fbstart(file);
if (bindex >= 0)
/*
* calls fput() instead of filp_close(),
* since no dnotify or lock for the lower file.
*/
for (; bindex <= bend; bindex++)
au_set_h_fptr(file, bindex, NULL);
finfo = au_fi(file);
au_dbg_verify_hf(finfo);
kfree(finfo->fi_hfile);
fi_write_unlock(file);
AuRwDestroy(&finfo->fi_rwsem);
au_cache_free_finfo(finfo);
}
int au_do_open(struct file *file, int (*open)(struct file *file, int flags),
struct au_fidir *fidir)
{
int err;
struct dentry *dentry;
err = au_finfo_init(file, fidir);
if (unlikely(err))
goto out;
dentry = file->f_dentry;
di_read_lock_child(dentry, AuLock_IR);
err = open(file, vfsub_file_flags(file));
di_read_unlock(dentry, AuLock_IR);
fi_write_unlock(file);
if (unlikely(err)) {
au_fi(file)->fi_hdir = NULL;
au_finfo_fin(file);
}
out:
return err;
}
int au_do_open(struct file *file, int (*open)(struct file *file, int flags))
{
int err;
struct dentry *dentry;
struct super_block *sb;
dentry = file->f_dentry;
sb = dentry->d_sb;
si_read_lock(sb, AuLock_FLUSH);
err = au_finfo_init(file);
if (unlikely(err))
goto out;
di_read_lock_child(dentry, AuLock_IR);
err = open(file, vfsub_file_flags(file));
di_read_unlock(dentry, AuLock_IR);
fi_write_unlock(file);
if (unlikely(err))
au_finfo_fin(file);
out:
si_read_unlock(sb);
return err;
}
/* common functions to regular file and dir */
struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
struct file *file)
{
struct file *h_file;
struct dentry *h_dentry;
struct inode *h_inode;
struct super_block *sb;
struct au_branch *br;
struct path h_path;
int err, exec_flag;
/* a race condition can happen between open and unlink/rmdir */
h_file = ERR_PTR(-ENOENT);
h_dentry = au_h_dptr(dentry, bindex);
if (au_test_nfsd() && !h_dentry)
goto out;
h_inode = h_dentry->d_inode;
if (au_test_nfsd() && !h_inode)
goto out;
spin_lock(&h_dentry->d_lock);
err = (!d_unhashed(dentry) && d_unlinked(h_dentry))
|| !h_inode
/* || !dentry->d_inode->i_nlink */
;
spin_unlock(&h_dentry->d_lock);
if (unlikely(err))
goto out;
sb = dentry->d_sb;
br = au_sbr(sb, bindex);
h_file = ERR_PTR(-EACCES);
exec_flag = flags & __FMODE_EXEC;
if (exec_flag && (br->br_mnt->mnt_flags & MNT_NOEXEC))
goto out;
/* drop flags for writing */
if (au_test_ro(sb, bindex, dentry->d_inode))
flags = au_file_roflags(flags);
flags &= ~O_CREAT;
atomic_inc(&br->br_count);
h_path.dentry = h_dentry;
h_path.mnt = br->br_mnt;
if (!au_special_file(h_inode->i_mode))
h_file = vfsub_dentry_open(&h_path, flags);
else {
/* this block depends upon the configuration */
di_read_unlock(dentry, AuLock_IR);
fi_write_unlock(file);
si_read_unlock(sb);
h_file = vfsub_dentry_open(&h_path, flags);
si_noflush_read_lock(sb);
fi_write_lock(file);
di_read_lock_child(dentry, AuLock_IR);
}
if (IS_ERR(h_file))
goto out_br;
if (exec_flag) {
err = deny_write_access(h_file);
if (unlikely(err)) {
fput(h_file);
h_file = ERR_PTR(err);
goto out_br;
}
}
fsnotify_open(h_file);
goto out; /* success */
out_br:
atomic_dec(&br->br_count);
out:
return h_file;
}
int au_do_open(struct inode *inode, struct file *file,
int (*open)(struct file *file, int flags))
{
int err, coo;
struct dentry *dentry;
struct super_block *sb;
aufs_bindex_t bstart;
struct inode *h_dir, *dir;
dentry = file->f_dentry;
LKTRTrace("i%lu, %.*s\n", inode->i_ino, DLNPair(dentry));
sb = dentry->d_sb;
si_read_lock(sb);
coo = 0;
#if 0
switch (au_flag_test_coo(sb)) {
case AuFlag_COO_LEAF:
coo = !S_ISDIR(inode->i_mode);
break;
case AuFlag_COO_ALL:
coo = 1;
break;
}
#endif
err = au_init_finfo(file);
//if (LktrCond) {fi_write_unlock(file); fin_finfo(file); err = -1;}
if (unlikely(err))
goto out;
if (!coo) {
di_read_lock_child(dentry, AUFS_I_RLOCK);
bstart = dbstart(dentry);
} else {
di_write_lock_child(dentry);
bstart = dbstart(dentry);
if (test_ro(sb, bstart, dentry->d_inode)) {
err = do_coo(dentry, bstart);
if (err) {
di_write_unlock(dentry);
goto out_finfo;
}
bstart = dbstart(dentry);
}
di_downgrade_lock(dentry, AUFS_I_RLOCK);
}
// todo: remove this extra locks
dir = dentry->d_parent->d_inode;
if (!IS_ROOT(dentry))
ii_read_lock_parent(dir);
h_dir = au_h_iptr_i(dir, bstart);
hdir_lock(h_dir, dir, bstart);
err = open(file, file->f_flags);
//if (LktrCond) err = -1;
hdir_unlock(h_dir, dir, bstart);
if (!IS_ROOT(dentry))
ii_read_unlock(dir);
di_read_unlock(dentry, AUFS_I_RLOCK);
out_finfo:
fi_write_unlock(file);
if (unlikely(err))
au_fin_finfo(file);
//DbgFile(file);
out:
si_read_unlock(sb);
TraceErr(err);
return err;
}
static int au_cmoo(struct dentry *dentry)
{
int err, cmoo;
unsigned int udba;
struct path h_path;
struct au_pin pin;
struct au_cp_generic cpg = {
.dentry = dentry,
.bdst = -1,
.bsrc = -1,
.len = -1,
.pin = &pin,
.flags = AuCpup_DTIME | AuCpup_HOPEN
};
struct inode *inode, *delegated;
struct super_block *sb;
struct au_sbinfo *sbinfo;
struct au_fhsm *fhsm;
pid_t pid;
struct au_branch *br;
struct dentry *parent;
struct au_hinode *hdir;
DiMustWriteLock(dentry);
inode = dentry->d_inode;
IiMustWriteLock(inode);
err = 0;
if (IS_ROOT(dentry))
goto out;
cpg.bsrc = au_dbstart(dentry);
if (!cpg.bsrc)
goto out;
sb = dentry->d_sb;
sbinfo = au_sbi(sb);
fhsm = &sbinfo->si_fhsm;
pid = au_fhsm_pid(fhsm);
if (pid
&& (current->pid == pid
|| current->real_parent->pid == pid))
goto out;
br = au_sbr(sb, cpg.bsrc);
cmoo = au_br_cmoo(br->br_perm);
if (!cmoo)
goto out;
if (!S_ISREG(inode->i_mode))
cmoo &= AuBrAttr_COO_ALL;
if (!cmoo)
goto out;
parent = dget_parent(dentry);
di_write_lock_parent(parent);
err = au_wbr_do_copyup_bu(dentry, cpg.bsrc - 1);
cpg.bdst = err;
if (unlikely(err < 0)) {
err = 0; /* there is no upper writable branch */
goto out_dgrade;
}
AuDbg("bsrc %d, bdst %d\n", cpg.bsrc, cpg.bdst);
/* do not respect the coo attrib for the target branch */
err = au_cpup_dirs(dentry, cpg.bdst);
if (unlikely(err))
goto out_dgrade;
di_downgrade_lock(parent, AuLock_IR);
udba = au_opt_udba(sb);
err = au_pin(&pin, dentry, cpg.bdst, udba,
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
if (unlikely(err))
goto out_parent;
err = au_sio_cpup_simple(&cpg);
au_unpin(&pin);
if (unlikely(err))
goto out_parent;
if (!(cmoo & AuBrWAttr_MOO))
goto out_parent; /* success */
err = au_pin(&pin, dentry, cpg.bsrc, udba,
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
if (unlikely(err))
goto out_parent;
h_path.mnt = au_br_mnt(br);
h_path.dentry = au_h_dptr(dentry, cpg.bsrc);
hdir = au_hi(parent->d_inode, cpg.bsrc);
delegated = NULL;
err = vfsub_unlink(hdir->hi_inode, &h_path, &delegated, /*force*/1);
au_unpin(&pin);
/* todo: keep h_dentry or not? */
if (unlikely(err == -EWOULDBLOCK)) {
pr_warn("cannot retry for NFSv4 delegation"
" for an internal unlink\n");
iput(delegated);
}
if (unlikely(err)) {
pr_err("unlink %pd after coo failed (%d), ignored\n",
dentry, err);
err = 0;
}
goto out_parent; /* success */
out_dgrade:
di_downgrade_lock(parent, AuLock_IR);
out_parent:
di_read_unlock(parent, AuLock_IR);
dput(parent);
out:
AuTraceErr(err);
return err;
}
int au_do_open(struct file *file, int (*open)(struct file *file, int flags),
struct au_fidir *fidir)
{
int err;
struct dentry *dentry;
struct au_finfo *finfo;
err = au_finfo_init(file, fidir);
if (unlikely(err))
goto out;
dentry = file->f_path.dentry;
di_write_lock_child(dentry);
err = au_cmoo(dentry);
di_downgrade_lock(dentry, AuLock_IR);
if (!err)
err = open(file, vfsub_file_flags(file));
di_read_unlock(dentry, AuLock_IR);
finfo = au_fi(file);
if (!err) {
finfo->fi_file = file;
au_sphl_add(&finfo->fi_hlist,
&au_sbi(file->f_path.dentry->d_sb)->si_files);
}
fi_write_unlock(file);
if (unlikely(err)) {
finfo->fi_hdir = NULL;
au_finfo_fin(file);
}
out:
return err;
}