--- /dev/null
+/*
+ * Copyright (C) 2005-2011 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * dentry private data
+ */
+
+#include "aufs.h"
+
+void au_di_init_once(void *_dinfo)
+{
+ struct au_dinfo *dinfo = _dinfo;
+ static struct lock_class_key aufs_di;
+
+ au_rw_init(&dinfo->di_rwsem);
+ au_rw_class(&dinfo->di_rwsem, &aufs_di);
+}
+
+struct au_dinfo *au_di_alloc(struct super_block *sb, unsigned int lsc)
+{
+ struct au_dinfo *dinfo;
+ int nbr, i;
+
+ dinfo = au_cache_alloc_dinfo();
+ if (unlikely(!dinfo))
+ goto out;
+
+ nbr = au_sbend(sb) + 1;
+ if (nbr <= 0)
+ nbr = 1;
+ dinfo->di_hdentry = kcalloc(nbr, sizeof(*dinfo->di_hdentry), GFP_NOFS);
+ if (dinfo->di_hdentry) {
+ au_rw_write_lock_nested(&dinfo->di_rwsem, lsc);
+ dinfo->di_bstart = -1;
+ dinfo->di_bend = -1;
+ dinfo->di_bwh = -1;
+ dinfo->di_bdiropq = -1;
+ for (i = 0; i < nbr; i++)
+ dinfo->di_hdentry[i].hd_id = -1;
+ goto out;
+ }
+
+ au_cache_free_dinfo(dinfo);
+ dinfo = NULL;
+
+out:
+ return dinfo;
+}
+
+void au_di_free(struct au_dinfo *dinfo)
+{
+ struct au_hdentry *p;
+ aufs_bindex_t bend, bindex;
+
+ /* dentry may not be revalidated */
+ bindex = dinfo->di_bstart;
+ if (bindex >= 0) {
+ bend = dinfo->di_bend;
+ p = dinfo->di_hdentry + bindex;
+ while (bindex++ <= bend)
+ au_hdput(p++);
+ }
+ kfree(dinfo->di_hdentry);
+ au_cache_free_dinfo(dinfo);
+}
+
+void au_di_swap(struct au_dinfo *a, struct au_dinfo *b)
+{
+ struct au_hdentry *p;
+ aufs_bindex_t bi;
+
+ AuRwMustWriteLock(&a->di_rwsem);
+ AuRwMustWriteLock(&b->di_rwsem);
+
+#define DiSwap(v, name) \
+ do { \
+ v = a->di_##name; \
+ a->di_##name = b->di_##name; \
+ b->di_##name = v; \
+ } while (0)
+
+ DiSwap(p, hdentry);
+ DiSwap(bi, bstart);
+ DiSwap(bi, bend);
+ DiSwap(bi, bwh);
+ DiSwap(bi, bdiropq);
+ /* smp_mb(); */
+
+#undef DiSwap
+}
+
+void au_di_cp(struct au_dinfo *dst, struct au_dinfo *src)
+{
+ AuRwMustWriteLock(&dst->di_rwsem);
+ AuRwMustWriteLock(&src->di_rwsem);
+
+ dst->di_bstart = src->di_bstart;
+ dst->di_bend = src->di_bend;
+ dst->di_bwh = src->di_bwh;
+ dst->di_bdiropq = src->di_bdiropq;
+ /* smp_mb(); */
+}
+
+int au_di_init(struct dentry *dentry)
+{
+ int err;
+ struct super_block *sb;
+ struct au_dinfo *dinfo;
+
+ err = 0;
+ sb = dentry->d_sb;
+ dinfo = au_di_alloc(sb, AuLsc_DI_CHILD);
+ if (dinfo) {
+ atomic_set(&dinfo->di_generation, au_sigen(sb));
+ /* smp_mb(); */ /* atomic_set */
+ dentry->d_fsdata = dinfo;
+ } else
+ err = -ENOMEM;
+
+ return err;
+}
+
+void au_di_fin(struct dentry *dentry)
+{
+ struct au_dinfo *dinfo;
+
+ dinfo = au_di(dentry);
+ AuRwDestroy(&dinfo->di_rwsem);
+ au_di_free(dinfo);
+}
+
+int au_di_realloc(struct au_dinfo *dinfo, int nbr)
+{
+ int err, sz;
+ struct au_hdentry *hdp;
+
+ AuRwMustWriteLock(&dinfo->di_rwsem);
+
+ err = -ENOMEM;
+ sz = sizeof(*hdp) * (dinfo->di_bend + 1);
+ if (!sz)
+ sz = sizeof(*hdp);
+ hdp = au_kzrealloc(dinfo->di_hdentry, sz, sizeof(*hdp) * nbr, GFP_NOFS);
+ if (hdp) {
+ dinfo->di_hdentry = hdp;
+ err = 0;
+ }
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+static void do_ii_write_lock(struct inode *inode, unsigned int lsc)
+{
+ switch (lsc) {
+ case AuLsc_DI_CHILD:
+ ii_write_lock_child(inode);
+ break;
+ case AuLsc_DI_CHILD2:
+ ii_write_lock_child2(inode);
+ break;
+ case AuLsc_DI_CHILD3:
+ ii_write_lock_child3(inode);
+ break;
+ case AuLsc_DI_PARENT:
+ ii_write_lock_parent(inode);
+ break;
+ case AuLsc_DI_PARENT2:
+ ii_write_lock_parent2(inode);
+ break;
+ case AuLsc_DI_PARENT3:
+ ii_write_lock_parent3(inode);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static void do_ii_read_lock(struct inode *inode, unsigned int lsc)
+{
+ switch (lsc) {
+ case AuLsc_DI_CHILD:
+ ii_read_lock_child(inode);
+ break;
+ case AuLsc_DI_CHILD2:
+ ii_read_lock_child2(inode);
+ break;
+ case AuLsc_DI_CHILD3:
+ ii_read_lock_child3(inode);
+ break;
+ case AuLsc_DI_PARENT:
+ ii_read_lock_parent(inode);
+ break;
+ case AuLsc_DI_PARENT2:
+ ii_read_lock_parent2(inode);
+ break;
+ case AuLsc_DI_PARENT3:
+ ii_read_lock_parent3(inode);
+ break;
+ default:
+ BUG();
+ }
+}
+
+void di_read_lock(struct dentry *d, int flags, unsigned int lsc)
+{
+ au_rw_read_lock_nested(&au_di(d)->di_rwsem, lsc);
+ if (d->d_inode) {
+ if (au_ftest_lock(flags, IW))
+ do_ii_write_lock(d->d_inode, lsc);
+ else if (au_ftest_lock(flags, IR))
+ do_ii_read_lock(d->d_inode, lsc);
+ }
+}
+
+void di_read_unlock(struct dentry *d, int flags)
+{
+ if (d->d_inode) {
+ if (au_ftest_lock(flags, IW)) {
+ au_dbg_verify_dinode(d);
+ ii_write_unlock(d->d_inode);
+ } else if (au_ftest_lock(flags, IR)) {
+ au_dbg_verify_dinode(d);
+ ii_read_unlock(d->d_inode);
+ }
+ }
+ au_rw_read_unlock(&au_di(d)->di_rwsem);
+}
+
+void di_downgrade_lock(struct dentry *d, int flags)
+{
+ if (d->d_inode && au_ftest_lock(flags, IR))
+ ii_downgrade_lock(d->d_inode);
+ au_rw_dgrade_lock(&au_di(d)->di_rwsem);
+}
+
+void di_write_lock(struct dentry *d, unsigned int lsc)
+{
+ au_rw_write_lock_nested(&au_di(d)->di_rwsem, lsc);
+ if (d->d_inode)
+ do_ii_write_lock(d->d_inode, lsc);
+}
+
+void di_write_unlock(struct dentry *d)
+{
+ au_dbg_verify_dinode(d);
+ if (d->d_inode)
+ ii_write_unlock(d->d_inode);
+ au_rw_write_unlock(&au_di(d)->di_rwsem);
+}
+
+void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir)
+{
+ AuDebugOn(d1 == d2
+ || d1->d_inode == d2->d_inode
+ || d1->d_sb != d2->d_sb);
+
+ if (isdir && au_test_subdir(d1, d2)) {
+ di_write_lock_child(d1);
+ di_write_lock_child2(d2);
+ } else {
+ /* there should be no races */
+ di_write_lock_child(d2);
+ di_write_lock_child2(d1);
+ }
+}
+
+void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir)
+{
+ AuDebugOn(d1 == d2
+ || d1->d_inode == d2->d_inode
+ || d1->d_sb != d2->d_sb);
+
+ if (isdir && au_test_subdir(d1, d2)) {
+ di_write_lock_parent(d1);
+ di_write_lock_parent2(d2);
+ } else {
+ /* there should be no races */
+ di_write_lock_parent(d2);
+ di_write_lock_parent2(d1);
+ }
+}
+
+void di_write_unlock2(struct dentry *d1, struct dentry *d2)
+{
+ di_write_unlock(d1);
+ if (d1->d_inode == d2->d_inode)
+ au_rw_write_unlock(&au_di(d2)->di_rwsem);
+ else
+ di_write_unlock(d2);
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex)
+{
+ struct dentry *d;
+
+ DiMustAnyLock(dentry);
+
+ if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
+ return NULL;
+ AuDebugOn(bindex < 0);
+ d = au_di(dentry)->di_hdentry[0 + bindex].hd_dentry;
+ AuDebugOn(d && d->d_count <= 0);
+ return d;
+}
+
+/*
+ * extended version of au_h_dptr().
+ * returns a hashed and positive h_dentry in bindex, NULL, or error.
+ */
+struct dentry *au_h_d_alias(struct dentry *dentry, aufs_bindex_t bindex)
+{
+ struct dentry *h_dentry;
+ struct inode *inode, *h_inode;
+
+ inode = dentry->d_inode;
+ AuDebugOn(!inode);
+
+ h_dentry = NULL;
+ if (au_dbstart(dentry) <= bindex
+ && bindex <= au_dbend(dentry))
+ h_dentry = au_h_dptr(dentry, bindex);
+ if (h_dentry && !au_d_hashed_positive(h_dentry)) {
+ dget(h_dentry);
+ goto out; /* success */
+ }
+
+ AuDebugOn(bindex < au_ibstart(inode));
+ AuDebugOn(au_ibend(inode) < bindex);
+ h_inode = au_h_iptr(inode, bindex);
+ h_dentry = d_find_alias(h_inode);
+ if (h_dentry) {
+ if (!IS_ERR(h_dentry)) {
+ if (!au_d_hashed_positive(h_dentry))
+ goto out; /* success */
+ dput(h_dentry);
+ } else
+ goto out;
+ }
+
+ if (au_opt_test(au_mntflags(dentry->d_sb), PLINK)) {
+ h_dentry = au_plink_lkup(inode, bindex);
+ AuDebugOn(!h_dentry);
+ if (!IS_ERR(h_dentry)) {
+ if (!au_d_hashed_positive(h_dentry))
+ goto out; /* success */
+ dput(h_dentry);
+ h_dentry = NULL;
+ }
+ }
+
+out:
+ AuDbgDentry(h_dentry);
+ return h_dentry;
+}
+
+aufs_bindex_t au_dbtail(struct dentry *dentry)
+{
+ aufs_bindex_t bend, bwh;
+
+ bend = au_dbend(dentry);
+ if (0 <= bend) {
+ bwh = au_dbwh(dentry);
+ if (!bwh)
+ return bwh;
+ if (0 < bwh && bwh < bend)
+ return bwh - 1;
+ }
+ return bend;
+}
+
+aufs_bindex_t au_dbtaildir(struct dentry *dentry)
+{
+ aufs_bindex_t bend, bopq;
+
+ bend = au_dbtail(dentry);
+ if (0 <= bend) {
+ bopq = au_dbdiropq(dentry);
+ if (0 <= bopq && bopq < bend)
+ bend = bopq;
+ }
+ return bend;
+}
+
+/* ---------------------------------------------------------------------- */
+
+void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
+ struct dentry *h_dentry)
+{
+ struct au_hdentry *hd = au_di(dentry)->di_hdentry + bindex;
+ struct au_branch *br;
+
+ DiMustWriteLock(dentry);
+
+ au_hdput(hd);
+ hd->hd_dentry = h_dentry;
+ if (h_dentry) {
+ br = au_sbr(dentry->d_sb, bindex);
+ hd->hd_id = br->br_id;
+ }
+}
+
+int au_dbrange_test(struct dentry *dentry)
+{
+ int err;
+ aufs_bindex_t bstart, bend;
+
+ err = 0;
+ bstart = au_dbstart(dentry);
+ bend = au_dbend(dentry);
+ if (bstart >= 0)
+ AuDebugOn(bend < 0 && bstart > bend);
+ else {
+ err = -EIO;
+ AuDebugOn(bend >= 0);
+ }
+
+ return err;
+}
+
+int au_digen_test(struct dentry *dentry, unsigned int sigen)
+{
+ int err;
+
+ err = 0;
+ if (unlikely(au_digen(dentry) != sigen
+ || au_iigen_test(dentry->d_inode, sigen)))
+ err = -EIO;
+
+ return err;
+}
+
+void au_update_digen(struct dentry *dentry)
+{
+ atomic_set(&au_di(dentry)->di_generation, au_sigen(dentry->d_sb));
+ /* smp_mb(); */ /* atomic_set */
+}
+
+void au_update_dbrange(struct dentry *dentry, int do_put_zero)
+{
+ struct au_dinfo *dinfo;
+ struct dentry *h_d;
+ struct au_hdentry *hdp;
+
+ DiMustWriteLock(dentry);
+
+ dinfo = au_di(dentry);
+ if (!dinfo || dinfo->di_bstart < 0)
+ return;
+
+ hdp = dinfo->di_hdentry;
+ if (do_put_zero) {
+ aufs_bindex_t bindex, bend;
+
+ bend = dinfo->di_bend;
+ for (bindex = dinfo->di_bstart; bindex <= bend; bindex++) {
+ h_d = hdp[0 + bindex].hd_dentry;
+ if (h_d && !h_d->d_inode)
+ au_set_h_dptr(dentry, bindex, NULL);
+ }
+ }
+
+ dinfo->di_bstart = -1;
+ while (++dinfo->di_bstart <= dinfo->di_bend)
+ if (hdp[0 + dinfo->di_bstart].hd_dentry)
+ break;
+ if (dinfo->di_bstart > dinfo->di_bend) {
+ dinfo->di_bstart = -1;
+ dinfo->di_bend = -1;
+ return;
+ }
+
+ dinfo->di_bend++;
+ while (0 <= --dinfo->di_bend)
+ if (hdp[0 + dinfo->di_bend].hd_dentry)
+ break;
+ AuDebugOn(dinfo->di_bstart > dinfo->di_bend || dinfo->di_bend < 0);
+}
+
+void au_update_dbstart(struct dentry *dentry)
+{
+ aufs_bindex_t bindex, bend;
+ struct dentry *h_dentry;
+
+ bend = au_dbend(dentry);
+ for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
+ h_dentry = au_h_dptr(dentry, bindex);
+ if (!h_dentry)
+ continue;
+ if (h_dentry->d_inode) {
+ au_set_dbstart(dentry, bindex);
+ return;
+ }
+ au_set_h_dptr(dentry, bindex, NULL);
+ }
+}
+
+void au_update_dbend(struct dentry *dentry)
+{
+ aufs_bindex_t bindex, bstart;
+ struct dentry *h_dentry;
+
+ bstart = au_dbstart(dentry);
+ for (bindex = au_dbend(dentry); bindex >= bstart; bindex--) {
+ h_dentry = au_h_dptr(dentry, bindex);
+ 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;
+}
git.openpandora.org / pandora-kernel.git / blobdiff