From 2c887e2359f6e7217cdaa17994ca94ef328b658f Mon Sep 17 00:00:00 2001 From: KaiGai Kohei Date: Sat, 24 Jun 2006 09:16:50 +0900 Subject: [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 Signed-off-by: David Woodhouse --- fs/jffs2/xattr.c | 25 +++++++++++-------------- fs/jffs2/xattr.h | 2 +- 2 files changed, 12 insertions(+), 15 deletions(-) (limited to 'fs') diff --git a/fs/jffs2/xattr.c b/fs/jffs2/xattr.c index 7622f79cb5b4..18e66dbf23b4 100644 --- a/fs/jffs2/xattr.c +++ b/fs/jffs2/xattr.c @@ -345,7 +345,7 @@ static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c, && xd->value_len==xsize && !strcmp(xd->xname, xname) && !memcmp(xd->xvalue, xvalue, xsize)) { - xd->refcnt++; + atomic_inc(&xd->refcnt); return xd; } } @@ -365,7 +365,7 @@ static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c, strcpy(data, xname); memcpy(data + name_len + 1, xvalue, xsize); - xd->refcnt = 1; + atomic_set(&xd->refcnt, 1); xd->xid = ++c->highest_xid; xd->flags |= JFFS2_XFLAGS_HOT; xd->xprefix = xprefix; @@ -397,7 +397,7 @@ static struct jffs2_xattr_datum *create_xattr_datum(struct jffs2_sb_info *c, static void delete_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd) { /* must be called under down_write(xattr_sem) */ - BUG_ON(xd->refcnt); + BUG_ON(atomic_read(&xd->refcnt)); unload_xattr_datum(c, xd); xd->flags |= JFFS2_XFLAGS_DEAD; @@ -580,7 +580,7 @@ static void delete_xattr_ref(struct jffs2_sb_info *c, struct jffs2_xattr_ref *re dbg_xattr("xref(ino=%u, xid=%u, xseqno=%u) was removed.\n", ref->ino, ref->xid, ref->xseqno); - if (!--xd->refcnt) + if (atomic_dec_and_test(&xd->refcnt)) delete_xattr_datum(c, xd); } @@ -612,8 +612,7 @@ void jffs2_xattr_free_inode(struct jffs2_sb_info *c, struct jffs2_inode_cache *i for (ref = ic->xref; ref; ref = _ref) { _ref = ref->next; xd = ref->xd; - xd->refcnt--; - if (!xd->refcnt) { + if (atomic_dec_and_test(&xd->refcnt)) { unload_xattr_datum(c, xd); jffs2_free_xattr_datum(xd); } @@ -835,7 +834,7 @@ void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c) } ref->xd = xd; ref->ic = ic; - xd->refcnt++; + atomic_inc(&xd->refcnt); ref->next = ic->xref; ic->xref = ref; } @@ -846,7 +845,7 @@ void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c) list_for_each_entry_safe(xd, _xd, &c->xattrindex[i], xindex) { xdatum_count++; list_del_init(&xd->xindex); - if (!xd->refcnt) { + if (!atomic_read(&xd->refcnt)) { dbg_xattr("xdatum(xid=%u, version=%u) is orphan.\n", xd->xid, xd->version); xd->flags |= JFFS2_XFLAGS_DEAD; @@ -1120,7 +1119,7 @@ int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname, ref->next = c->xref_dead_list; c->xref_dead_list = ref; spin_unlock(&c->erase_completion_lock); - if (!--xd->refcnt) + if (atomic_dec_and_test(&xd->refcnt)) delete_xattr_datum(c, xd); } else { ref->ic = ic; @@ -1157,8 +1156,7 @@ int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname, down_write(&c->xattr_sem); if (rc) { JFFS2_WARNING("jffs2_reserve_space()=%d, request=%u\n", rc, request); - xd->refcnt--; - if (!xd->refcnt) + if (atomic_dec_and_test(&xd->refcnt)) delete_xattr_datum(c, xd); up_write(&c->xattr_sem); return rc; @@ -1172,8 +1170,7 @@ int do_jffs2_setxattr(struct inode *inode, int xprefix, const char *xname, ic->xref = ref; } rc = PTR_ERR(newref); - xd->refcnt--; - if (!xd->refcnt) + if (atomic_dec_and_test(&xd->refcnt)) delete_xattr_datum(c, xd); } else if (ref) { delete_xattr_ref(c, ref); @@ -1304,7 +1301,7 @@ int jffs2_verify_xattr(struct jffs2_sb_info *c) void jffs2_release_xattr_datum(struct jffs2_sb_info *c, struct jffs2_xattr_datum *xd) { /* must be called under spin_lock(&c->erase_completion_lock) */ - if (xd->refcnt > 0 || xd->node != (void *)xd) + if (atomic_read(&xd->refcnt) || xd->node != (void *)xd) return; list_del(&xd->xindex); diff --git a/fs/jffs2/xattr.h b/fs/jffs2/xattr.h index 4a10abc6d917..06a5c69dcf8b 100644 --- a/fs/jffs2/xattr.h +++ b/fs/jffs2/xattr.h @@ -28,7 +28,7 @@ struct jffs2_xattr_datum uint16_t xprefix; /* see JFFS2_XATTR_PREFIX_* */ struct list_head xindex; /* chained from c->xattrindex[n] */ - uint32_t refcnt; /* # of xattr_ref refers this */ + atomic_t refcnt; /* # of xattr_ref refers this */ uint32_t xid; uint32_t version; -- cgit v1.2.2