543 lines
11 KiB
C
543 lines
11 KiB
C
/*
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* Copyright (C) 2005-2014 Junjiro R. Okajima
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*
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* This program, aufs is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* dentry private data
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*/
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#include "aufs.h"
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void au_di_init_once(void *_dinfo)
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{
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struct au_dinfo *dinfo = _dinfo;
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static struct lock_class_key aufs_di;
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au_rw_init(&dinfo->di_rwsem);
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au_rw_class(&dinfo->di_rwsem, &aufs_di);
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}
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struct au_dinfo *au_di_alloc(struct super_block *sb, unsigned int lsc)
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{
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struct au_dinfo *dinfo;
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int nbr, i;
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dinfo = au_cache_alloc_dinfo();
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if (unlikely(!dinfo))
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goto out;
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nbr = au_sbend(sb) + 1;
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if (nbr <= 0)
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nbr = 1;
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dinfo->di_hdentry = kcalloc(nbr, sizeof(*dinfo->di_hdentry), GFP_NOFS);
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if (dinfo->di_hdentry) {
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au_rw_write_lock_nested(&dinfo->di_rwsem, lsc);
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dinfo->di_bstart = -1;
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dinfo->di_bend = -1;
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dinfo->di_bwh = -1;
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dinfo->di_bdiropq = -1;
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for (i = 0; i < nbr; i++)
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dinfo->di_hdentry[i].hd_id = -1;
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goto out;
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}
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au_cache_free_dinfo(dinfo);
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dinfo = NULL;
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out:
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return dinfo;
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}
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void au_di_free(struct au_dinfo *dinfo)
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{
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struct au_hdentry *p;
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aufs_bindex_t bend, bindex;
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/* dentry may not be revalidated */
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bindex = dinfo->di_bstart;
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if (bindex >= 0) {
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bend = dinfo->di_bend;
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p = dinfo->di_hdentry + bindex;
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while (bindex++ <= bend)
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au_hdput(p++);
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}
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kfree(dinfo->di_hdentry);
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au_cache_free_dinfo(dinfo);
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}
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void au_di_swap(struct au_dinfo *a, struct au_dinfo *b)
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{
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struct au_hdentry *p;
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aufs_bindex_t bi;
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AuRwMustWriteLock(&a->di_rwsem);
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AuRwMustWriteLock(&b->di_rwsem);
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#define DiSwap(v, name) \
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do { \
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v = a->di_##name; \
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a->di_##name = b->di_##name; \
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b->di_##name = v; \
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} while (0)
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DiSwap(p, hdentry);
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DiSwap(bi, bstart);
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DiSwap(bi, bend);
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DiSwap(bi, bwh);
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DiSwap(bi, bdiropq);
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/* smp_mb(); */
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#undef DiSwap
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}
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void au_di_cp(struct au_dinfo *dst, struct au_dinfo *src)
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{
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AuRwMustWriteLock(&dst->di_rwsem);
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AuRwMustWriteLock(&src->di_rwsem);
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dst->di_bstart = src->di_bstart;
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dst->di_bend = src->di_bend;
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dst->di_bwh = src->di_bwh;
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dst->di_bdiropq = src->di_bdiropq;
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/* smp_mb(); */
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}
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int au_di_init(struct dentry *dentry)
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{
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int err;
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struct super_block *sb;
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struct au_dinfo *dinfo;
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err = 0;
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sb = dentry->d_sb;
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dinfo = au_di_alloc(sb, AuLsc_DI_CHILD);
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if (dinfo) {
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atomic_set(&dinfo->di_generation, au_sigen(sb));
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/* smp_mb(); */ /* atomic_set */
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dentry->d_fsdata = dinfo;
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} else
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err = -ENOMEM;
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return err;
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}
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void au_di_fin(struct dentry *dentry)
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{
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struct au_dinfo *dinfo;
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dinfo = au_di(dentry);
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AuRwDestroy(&dinfo->di_rwsem);
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au_di_free(dinfo);
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}
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int au_di_realloc(struct au_dinfo *dinfo, int nbr)
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{
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int err, sz;
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struct au_hdentry *hdp;
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AuRwMustWriteLock(&dinfo->di_rwsem);
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err = -ENOMEM;
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sz = sizeof(*hdp) * (dinfo->di_bend + 1);
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if (!sz)
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sz = sizeof(*hdp);
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hdp = au_kzrealloc(dinfo->di_hdentry, sz, sizeof(*hdp) * nbr, GFP_NOFS);
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if (hdp) {
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dinfo->di_hdentry = hdp;
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err = 0;
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}
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return err;
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}
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/* ---------------------------------------------------------------------- */
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static void do_ii_write_lock(struct inode *inode, unsigned int lsc)
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{
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switch (lsc) {
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case AuLsc_DI_CHILD:
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ii_write_lock_child(inode);
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break;
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case AuLsc_DI_CHILD2:
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ii_write_lock_child2(inode);
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break;
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case AuLsc_DI_CHILD3:
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ii_write_lock_child3(inode);
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break;
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case AuLsc_DI_PARENT:
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ii_write_lock_parent(inode);
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break;
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case AuLsc_DI_PARENT2:
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ii_write_lock_parent2(inode);
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break;
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case AuLsc_DI_PARENT3:
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ii_write_lock_parent3(inode);
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break;
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default:
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BUG();
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}
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}
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static void do_ii_read_lock(struct inode *inode, unsigned int lsc)
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{
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switch (lsc) {
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case AuLsc_DI_CHILD:
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ii_read_lock_child(inode);
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break;
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case AuLsc_DI_CHILD2:
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ii_read_lock_child2(inode);
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break;
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case AuLsc_DI_CHILD3:
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ii_read_lock_child3(inode);
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break;
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case AuLsc_DI_PARENT:
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ii_read_lock_parent(inode);
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break;
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case AuLsc_DI_PARENT2:
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ii_read_lock_parent2(inode);
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break;
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case AuLsc_DI_PARENT3:
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ii_read_lock_parent3(inode);
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break;
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default:
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BUG();
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}
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}
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void di_read_lock(struct dentry *d, int flags, unsigned int lsc)
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{
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au_rw_read_lock_nested(&au_di(d)->di_rwsem, lsc);
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if (d->d_inode) {
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if (au_ftest_lock(flags, IW))
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do_ii_write_lock(d->d_inode, lsc);
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else if (au_ftest_lock(flags, IR))
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do_ii_read_lock(d->d_inode, lsc);
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}
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}
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void di_read_unlock(struct dentry *d, int flags)
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{
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if (d->d_inode) {
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if (au_ftest_lock(flags, IW)) {
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au_dbg_verify_dinode(d);
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ii_write_unlock(d->d_inode);
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} else if (au_ftest_lock(flags, IR)) {
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au_dbg_verify_dinode(d);
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ii_read_unlock(d->d_inode);
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}
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}
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au_rw_read_unlock(&au_di(d)->di_rwsem);
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}
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void di_downgrade_lock(struct dentry *d, int flags)
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{
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if (d->d_inode && au_ftest_lock(flags, IR))
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ii_downgrade_lock(d->d_inode);
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au_rw_dgrade_lock(&au_di(d)->di_rwsem);
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}
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void di_write_lock(struct dentry *d, unsigned int lsc)
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{
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au_rw_write_lock_nested(&au_di(d)->di_rwsem, lsc);
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if (d->d_inode)
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do_ii_write_lock(d->d_inode, lsc);
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}
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void di_write_unlock(struct dentry *d)
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{
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au_dbg_verify_dinode(d);
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if (d->d_inode)
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ii_write_unlock(d->d_inode);
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au_rw_write_unlock(&au_di(d)->di_rwsem);
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}
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void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir)
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{
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AuDebugOn(d1 == d2
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|| d1->d_inode == d2->d_inode
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|| d1->d_sb != d2->d_sb);
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if (isdir && au_test_subdir(d1, d2)) {
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di_write_lock_child(d1);
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di_write_lock_child2(d2);
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} else {
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/* there should be no races */
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di_write_lock_child(d2);
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di_write_lock_child2(d1);
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}
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}
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void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir)
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{
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AuDebugOn(d1 == d2
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|| d1->d_inode == d2->d_inode
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|| d1->d_sb != d2->d_sb);
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if (isdir && au_test_subdir(d1, d2)) {
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di_write_lock_parent(d1);
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di_write_lock_parent2(d2);
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} else {
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/* there should be no races */
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di_write_lock_parent(d2);
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di_write_lock_parent2(d1);
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}
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}
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void di_write_unlock2(struct dentry *d1, struct dentry *d2)
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{
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di_write_unlock(d1);
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if (d1->d_inode == d2->d_inode)
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au_rw_write_unlock(&au_di(d2)->di_rwsem);
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else
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di_write_unlock(d2);
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}
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/* ---------------------------------------------------------------------- */
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struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex)
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{
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struct dentry *d;
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DiMustAnyLock(dentry);
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if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
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return NULL;
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AuDebugOn(bindex < 0);
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d = au_di(dentry)->di_hdentry[0 + bindex].hd_dentry;
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AuDebugOn(d && d->d_count <= 0);
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return d;
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}
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/*
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* extended version of au_h_dptr().
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* returns a hashed and positive h_dentry in bindex, NULL, or error.
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*/
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struct dentry *au_h_d_alias(struct dentry *dentry, aufs_bindex_t bindex)
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{
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struct dentry *h_dentry;
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struct inode *inode, *h_inode;
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inode = dentry->d_inode;
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AuDebugOn(!inode);
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h_dentry = NULL;
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if (au_dbstart(dentry) <= bindex
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&& bindex <= au_dbend(dentry))
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h_dentry = au_h_dptr(dentry, bindex);
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if (h_dentry && !au_d_hashed_positive(h_dentry)) {
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dget(h_dentry);
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goto out; /* success */
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}
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AuDebugOn(bindex < au_ibstart(inode));
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AuDebugOn(au_ibend(inode) < bindex);
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h_inode = au_h_iptr(inode, bindex);
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h_dentry = d_find_alias(h_inode);
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if (h_dentry) {
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if (!IS_ERR(h_dentry)) {
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if (!au_d_hashed_positive(h_dentry))
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goto out; /* success */
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dput(h_dentry);
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} else
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goto out;
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}
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if (au_opt_test(au_mntflags(dentry->d_sb), PLINK)) {
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h_dentry = au_plink_lkup(inode, bindex);
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AuDebugOn(!h_dentry);
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if (!IS_ERR(h_dentry)) {
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if (!au_d_hashed_positive(h_dentry))
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goto out; /* success */
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dput(h_dentry);
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h_dentry = NULL;
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}
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}
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out:
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AuDbgDentry(h_dentry);
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return h_dentry;
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}
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aufs_bindex_t au_dbtail(struct dentry *dentry)
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{
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aufs_bindex_t bend, bwh;
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bend = au_dbend(dentry);
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if (0 <= bend) {
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bwh = au_dbwh(dentry);
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if (!bwh)
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return bwh;
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if (0 < bwh && bwh < bend)
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return bwh - 1;
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}
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return bend;
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}
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aufs_bindex_t au_dbtaildir(struct dentry *dentry)
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{
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aufs_bindex_t bend, bopq;
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bend = au_dbtail(dentry);
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if (0 <= bend) {
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bopq = au_dbdiropq(dentry);
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if (0 <= bopq && bopq < bend)
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bend = bopq;
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}
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return bend;
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}
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/* ---------------------------------------------------------------------- */
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void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
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struct dentry *h_dentry)
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{
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struct au_hdentry *hd = au_di(dentry)->di_hdentry + bindex;
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struct au_branch *br;
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DiMustWriteLock(dentry);
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au_hdput(hd);
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hd->hd_dentry = h_dentry;
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if (h_dentry) {
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br = au_sbr(dentry->d_sb, bindex);
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hd->hd_id = br->br_id;
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}
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}
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int au_dbrange_test(struct dentry *dentry)
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{
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int err;
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aufs_bindex_t bstart, bend;
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err = 0;
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bstart = au_dbstart(dentry);
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bend = au_dbend(dentry);
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if (bstart >= 0)
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AuDebugOn(bend < 0 && bstart > bend);
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else {
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err = -EIO;
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AuDebugOn(bend >= 0);
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}
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return err;
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}
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int au_digen_test(struct dentry *dentry, unsigned int sigen)
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{
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int err;
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err = 0;
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if (unlikely(au_digen(dentry) != sigen
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|| au_iigen_test(dentry->d_inode, sigen)))
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err = -EIO;
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return err;
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}
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void au_update_digen(struct dentry *dentry)
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{
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atomic_set(&au_di(dentry)->di_generation, au_sigen(dentry->d_sb));
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/* smp_mb(); */ /* atomic_set */
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}
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void au_update_dbrange(struct dentry *dentry, int do_put_zero)
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{
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struct au_dinfo *dinfo;
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struct dentry *h_d;
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struct au_hdentry *hdp;
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DiMustWriteLock(dentry);
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dinfo = au_di(dentry);
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if (!dinfo || dinfo->di_bstart < 0)
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return;
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hdp = dinfo->di_hdentry;
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if (do_put_zero) {
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aufs_bindex_t bindex, bend;
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bend = dinfo->di_bend;
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for (bindex = dinfo->di_bstart; bindex <= bend; bindex++) {
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h_d = hdp[0 + bindex].hd_dentry;
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if (h_d && !h_d->d_inode)
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au_set_h_dptr(dentry, bindex, NULL);
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}
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}
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dinfo->di_bstart = -1;
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while (++dinfo->di_bstart <= dinfo->di_bend)
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if (hdp[0 + dinfo->di_bstart].hd_dentry)
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break;
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if (dinfo->di_bstart > dinfo->di_bend) {
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dinfo->di_bstart = -1;
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dinfo->di_bend = -1;
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return;
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}
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dinfo->di_bend++;
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while (0 <= --dinfo->di_bend)
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if (hdp[0 + dinfo->di_bend].hd_dentry)
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break;
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AuDebugOn(dinfo->di_bstart > dinfo->di_bend || dinfo->di_bend < 0);
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}
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void au_update_dbstart(struct dentry *dentry)
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{
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aufs_bindex_t bindex, bend;
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struct dentry *h_dentry;
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bend = au_dbend(dentry);
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for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
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h_dentry = au_h_dptr(dentry, bindex);
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if (!h_dentry)
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continue;
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if (h_dentry->d_inode) {
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au_set_dbstart(dentry, bindex);
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return;
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}
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au_set_h_dptr(dentry, bindex, NULL);
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}
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}
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void au_update_dbend(struct dentry *dentry)
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{
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aufs_bindex_t bindex, bstart;
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struct dentry *h_dentry;
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bstart = au_dbstart(dentry);
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for (bindex = au_dbend(dentry); bindex >= bstart; bindex--) {
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h_dentry = au_h_dptr(dentry, bindex);
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if (!h_dentry)
|
|
continue;
|
|
if (h_dentry->d_inode) {
|
|
au_set_dbend(dentry, bindex);
|
|
return;
|
|
}
|
|
au_set_h_dptr(dentry, bindex, NULL);
|
|
}
|
|
}
|
|
|
|
int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry)
|
|
{
|
|
aufs_bindex_t bindex, bend;
|
|
|
|
bend = au_dbend(dentry);
|
|
for (bindex = au_dbstart(dentry); bindex <= bend; bindex++)
|
|
if (au_h_dptr(dentry, bindex) == h_dentry)
|
|
return bindex;
|
|
return -1;
|
|
}
|