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- Document more of the struct vnode locking protocol.

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- Slightly reformat a comment block.
This commit is contained in:
Jeff Roberson 2002-08-05 10:25:56 +00:00
parent 8947be9ba0
commit 973a3f4b94
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=101368
1 changed files with 12 additions and 11 deletions
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23
sys/sys/vnode.h
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@ -93,14 +93,15 @@ struct vpollinfo {
/*
* Reading or writing any of these items requires holding the appropriate lock.
* v_freelist is locked by the global vnode_free_list mutex.
* v_mntvnodes is locked by the global mntvnodes mutex.
* v_iflag, v_usecount, v_holdcount and v_writecount are
* locked by the v_interlock mutex.
* v_pollinfo is locked by the lock contained inside it.
* V vnode lock
* I inter lock
*
* Lock reference:
* V vnode lock
* I inter lock
* F freelist mutex
* M mntvnodes mutex
* P pollinfo lock
*/
struct vnode {
struct mtx v_interlock; /* lock on usecount and flag */
u_long v_iflag; /* I vnode flags (see below) */
@ -108,13 +109,13 @@ struct vnode {
int v_writecount; /* I ref count of writers */
long v_numoutput; /* I writes in progress */
struct thread *v_vxproc; /* I thread owning VXLOCK */
int v_holdcnt; /* I page & buffer references */
u_long v_vflag; /* V vnode flags */
int v_holdcnt; /* page & buffer references */
u_long v_id; /* capability identifier */
struct mount *v_mount; /* ptr to vfs we are in */
vop_t **v_op; /* vnode operations vector */
TAILQ_ENTRY(vnode) v_freelist; /* vnode freelist */
TAILQ_ENTRY(vnode) v_nmntvnodes; /* vnodes for mount point */
TAILQ_ENTRY(vnode) v_freelist; /* F vnode freelist */
TAILQ_ENTRY(vnode) v_nmntvnodes; /* M vnodes for mount point */
struct buflists v_cleanblkhd; /* SORTED clean blocklist */
struct buf *v_cleanblkroot; /* clean buf splay tree root */
struct buflists v_dirtyblkhd; /* SORTED dirty blocklist */
@ -143,7 +144,7 @@ struct vnode {
TAILQ_HEAD(, namecache) v_cache_dst; /* Cache entries to us */
struct vnode *v_dd; /* .. vnode */
u_long v_ddid; /* .. capability identifier */
struct vpollinfo *v_pollinfo;
struct vpollinfo *v_pollinfo; /* P Poll events */
struct label v_label; /* MAC label for vnode */
#ifdef DEBUG_LOCKS
const char *filename; /* Source file doing locking */