[JFFS2][XATTR] Re-define xd->refcnt as atomic_t
In jffs2_release_xattr_datum(), it refers xd->refcnt to ensure whether releasing xd is allowed or not. But we can't hold xattr_sem since this function is called under spin_lock(&c->erase_completion_lock). Thus we have to refer it without any locking. This patch redefine xd->refcnt as atomic_t. It enables to refer xd->refcnt without any locking. Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Signed-off-by: David Woodhouse <dwmw2@infradead.org>
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355ed4e141
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@ -345,7 +345,7 @@ static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
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&& xd->value_len==xsize
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&& xd->value_len==xsize
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&& !strcmp(xd->xname, xname)
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&& !strcmp(xd->xname, xname)
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&& !memcmp(xd->xvalue, xvalue, xsize)) {
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&& !memcmp(xd->xvalue, xvalue, xsize)) {
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xd->refcnt++;
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atomic_inc(&xd->refcnt);
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return xd;
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return xd;
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}
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}
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}
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}
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@ -365,7 +365,7 @@ static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
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strcpy(data, xname);
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strcpy(data, xname);
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memcpy(data + name_len + 1, xvalue, xsize);
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memcpy(data + name_len + 1, xvalue, xsize);
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xd->refcnt = 1;
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atomic_set(&xd->refcnt, 1);
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xd->xid = ++c->highest_xid;
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xd->xid = ++c->highest_xid;
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xd->flags |= JFFS2_XFLAGS_HOT;
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xd->flags |= JFFS2_XFLAGS_HOT;
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xd->xprefix = xprefix;
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xd->xprefix = xprefix;
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@ -397,7 +397,7 @@ static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c,
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static void delete_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
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static void delete_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
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{
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{
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/* must be called under down_write(xattr_sem) */
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/* must be called under down_write(xattr_sem) */
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BUG_ON(xd->refcnt);
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BUG_ON(atomic_read(&xd->refcnt));
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unload_xattr_datum(c, xd);
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unload_xattr_datum(c, xd);
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xd->flags |= JFFS2_XFLAGS_DEAD;
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xd->flags |= JFFS2_XFLAGS_DEAD;
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@ -580,7 +580,7 @@ static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *re
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dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
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dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n",
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ref->ino, ref->xid, ref->xseqno);
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ref->ino, ref->xid, ref->xseqno);
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if (!--xd->refcnt)
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if (atomic_dec_and_test(&xd->refcnt))
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delete_xattr_datum(c, xd);
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delete_xattr_datum(c, xd);
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}
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}
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@ -612,8 +612,7 @@ void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *i
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for (ref = ic->xref; ref; ref = _ref) {
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for (ref = ic->xref; ref; ref = _ref) {
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_ref = ref->next;
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_ref = ref->next;
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xd = ref->xd;
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xd = ref->xd;
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xd->refcnt--;
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if (atomic_dec_and_test(&xd->refcnt)) {
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if (!xd->refcnt) {
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unload_xattr_datum(c, xd);
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unload_xattr_datum(c, xd);
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jffs2_free_xattr_datum(xd);
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jffs2_free_xattr_datum(xd);
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}
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}
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@ -835,7 +834,7 @@ void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
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}
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}
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ref->xd = xd;
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ref->xd = xd;
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ref->ic = ic;
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ref->ic = ic;
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xd->refcnt++;
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atomic_inc(&xd->refcnt);
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ref->next = ic->xref;
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ref->next = ic->xref;
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ic->xref = ref;
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ic->xref = ref;
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}
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}
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@ -846,7 +845,7 @@ void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c)
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list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
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list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) {
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xdatum_count++;
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xdatum_count++;
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list_del_init(&xd->xindex);
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list_del_init(&xd->xindex);
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if (!xd->refcnt) {
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if (!atomic_read(&xd->refcnt)) {
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dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
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dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n",
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xd->xid, xd->version);
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xd->xid, xd->version);
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xd->flags |= JFFS2_XFLAGS_DEAD;
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xd->flags |= JFFS2_XFLAGS_DEAD;
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@ -1120,7 +1119,7 @@ int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
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ref->next = c->xref_dead_list;
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ref->next = c->xref_dead_list;
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c->xref_dead_list = ref;
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c->xref_dead_list = ref;
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spin_unlock(&c->erase_completion_lock);
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spin_unlock(&c->erase_completion_lock);
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if (!--xd->refcnt)
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if (atomic_dec_and_test(&xd->refcnt))
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delete_xattr_datum(c, xd);
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delete_xattr_datum(c, xd);
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} else {
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} else {
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ref->ic = ic;
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ref->ic = ic;
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@ -1157,8 +1156,7 @@ int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
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down_write(&c->xattr_sem);
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down_write(&c->xattr_sem);
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if (rc) {
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if (rc) {
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JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
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JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request);
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xd->refcnt--;
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if (atomic_dec_and_test(&xd->refcnt))
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if (!xd->refcnt)
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delete_xattr_datum(c, xd);
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delete_xattr_datum(c, xd);
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up_write(&c->xattr_sem);
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up_write(&c->xattr_sem);
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return rc;
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return rc;
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@ -1172,8 +1170,7 @@ int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname,
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ic->xref = ref;
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ic->xref = ref;
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}
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}
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rc = PTR_ERR(newref);
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rc = PTR_ERR(newref);
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xd->refcnt--;
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if (atomic_dec_and_test(&xd->refcnt))
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if (!xd->refcnt)
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delete_xattr_datum(c, xd);
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delete_xattr_datum(c, xd);
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} else if (ref) {
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} else if (ref) {
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delete_xattr_ref(c, ref);
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delete_xattr_ref(c, ref);
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@ -1304,7 +1301,7 @@ int jffs2_verify_xattr(struct jffs2_sb_info *c)
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void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
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void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd)
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{
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{
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/* must be called under spin_lock(&c->erase_completion_lock) */
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/* must be called under spin_lock(&c->erase_completion_lock) */
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if (xd->refcnt > 0 || xd->node != (void *)xd)
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if (atomic_read(&xd->refcnt) || xd->node != (void *)xd)
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return;
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return;
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list_del(&xd->xindex);
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list_del(&xd->xindex);
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@ -28,7 +28,7 @@ struct jffs2_xattr_datum
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uint16_t xprefix; /* see JFFS2_XATTR_PREFIX_* */
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uint16_t xprefix; /* see JFFS2_XATTR_PREFIX_* */
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struct list_head xindex; /* chained from c->xattrindex[n] */
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struct list_head xindex; /* chained from c->xattrindex[n] */
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uint32_t refcnt; /* # of xattr_ref refers this */
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atomic_t refcnt; /* # of xattr_ref refers this */
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uint32_t xid;
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uint32_t xid;
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uint32_t version;
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uint32_t version;
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