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/*
* Copyright (C) 2005-2008 Junjiro 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, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
/*
* file private data
*
* $Id: finfo.c,v 1.2 2008/04/21 01:35:14 sfjro Exp $
*/
#include "aufs.h"
struct au_finfo *au_fi(struct file *file)
{
struct au_finfo *finfo = file->private_data;
AuDebugOn(!finfo
|| !finfo->fi_hfile
|| (0 < finfo->fi_bend
&& (/* au_sbi(file->f_dentry->d_sb)->si_bend
< finfo->fi_bend
|| */ finfo->fi_bend < finfo->fi_bstart)));
return finfo;
}
struct au_branch *au_fbr(struct file *file, aufs_bindex_t bindex)
{
struct au_finfo *finfo = au_fi(file);
struct au_hfile *hf;
FiMustAnyLock(file);
AuDebugOn(!finfo
|| finfo->fi_bstart < 0
|| bindex < finfo->fi_bstart
|| finfo->fi_bend < bindex);
hf = finfo->fi_hfile + bindex;
AuDebugOn(hf->hf_br && au_br_count(hf->hf_br) <= 0);
return hf->hf_br;
}
struct file *au_h_fptr(struct file *file, aufs_bindex_t bindex)
{
struct au_finfo *finfo = au_fi(file);
struct au_hfile *hf;
FiMustAnyLock(file);
AuDebugOn(!finfo
|| finfo->fi_bstart < 0
|| bindex < finfo->fi_bstart
|| finfo->fi_bend < bindex);
hf = finfo->fi_hfile + bindex;
AuDebugOn(hf->hf_file
&& file_count(hf->hf_file) <= 0
&& au_br_count(hf->hf_br) <= 0);
return hf->hf_file;
}
void au_hfput(struct au_hfile *hf)
{
if (hf->hf_file->f_mode & FMODE_EXEC)
au_allow_write_access(hf->hf_file);
fput(hf->hf_file);
hf->hf_file = NULL;
AuDebugOn(!hf->hf_br);
au_br_put(hf->hf_br);
hf->hf_br = NULL;
}
void au_set_h_fptr(struct file *file, aufs_bindex_t bindex, struct file *val)
{
struct au_finfo *finfo = au_fi(file);
struct au_hfile *hf;
FiMustWriteLock(file);
AuDebugOn(!finfo
|| finfo->fi_bstart < 0
|| bindex < finfo->fi_bstart
|| finfo->fi_bend < bindex);
AuDebugOn(val && file_count(val) <= 0);
hf = finfo->fi_hfile + bindex;
AuDebugOn(val && hf->hf_file);
if (hf->hf_file)
au_hfput(hf);
if (val) {
hf->hf_file = val;
hf->hf_br = au_sbr(file->f_dentry->d_sb, bindex);
}
}
void au_finfo_fin(struct file *file)
{
struct au_finfo *finfo;
struct dentry *dentry;
aufs_bindex_t bindex, bend;
dentry = file->f_dentry;
LKTRTrace("%.*s\n", AuDLNPair(dentry));
SiMustAnyLock(dentry->d_sb);
fi_write_lock(file);
bend = au_fbend(file);
bindex = au_fbstart(file);
if (bindex >= 0)
for (; bindex <= bend; bindex++)
au_set_h_fptr(file, bindex, NULL);
finfo = au_fi(file);
#ifdef CONFIG_AUFS_DEBUG
if (finfo->fi_bstart >= 0) {
bend = au_fbend(file);
for (bindex = finfo->fi_bstart; bindex <= bend; bindex++) {
struct au_hfile *hf;
hf = finfo->fi_hfile + bindex;
AuDebugOn(hf->hf_file || hf->hf_br);
}
}
#endif
kfree(finfo->fi_hfile);
fi_write_unlock(file);
au_cache_free_finfo(finfo);
//file->private_data = NULL;
}
int au_finfo_init(struct file *file)
{
struct au_finfo *finfo;
struct dentry *dentry;
union {
void *p;
unsigned long ul;
} u;
dentry = file->f_dentry;
LKTRTrace("%.*s\n", AuDLNPair(dentry));
AuDebugOn(!dentry->d_inode);
finfo = au_cache_alloc_finfo();
if (finfo) {
finfo->fi_hfile = kcalloc(au_sbend(dentry->d_sb) + 1,
sizeof(*finfo->fi_hfile), GFP_KERNEL);
if (finfo->fi_hfile) {
au_rw_init_wlock(&finfo->fi_rwsem);
finfo->fi_bstart = -1;
finfo->fi_bend = -1;
atomic_set(&finfo->fi_generation, au_digen(dentry));
//smp_mb(); /* atomic_set */
/*
* a dirty trick for handling FMODE_EXEC and
* deny_write_access().
* because FMODE_EXEC flag is not passed to
* f_op->open(),
* aufs set it to file->private_data temporary in lookup
* or dentry revalidation operations.
* restore the flag to f_mode here.
*/
u.p = file->private_data;
if (u.ul & FMODE_EXEC) {
file->f_mode |= FMODE_EXEC;
smp_mb(); /* flush f_mode */
}
file->private_data = finfo;
return 0; /* success */
}
au_cache_free_finfo(finfo);
}
AuTraceErr(-ENOMEM);
return -ENOMEM;
}
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