[XFS] shrink mrlock_t
The writer field is not needed for non_DEBU builds so remove it. While
we're at i also clean up the interface for is locked asserts to go through
and xfs_iget.c helper with an interface like the xfs_ilock routines to
isolated the XFS codebase from mrlock internals. That way we can kill
mrlock_t entirely once rw_semaphores grow an islocked facility. Also
remove unused flags to the ilock family of functions.
SGI-PV: 976035
SGI-Modid: xfs-linux-melb:xfs-kern:30902a
Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
diff --git a/fs/xfs/linux-2.6/mrlock.h b/fs/xfs/linux-2.6/mrlock.h
index c110bb0..ff6a198 100644
--- a/fs/xfs/linux-2.6/mrlock.h
+++ b/fs/xfs/linux-2.6/mrlock.h
@@ -20,29 +20,24 @@
#include <linux/rwsem.h>
-enum { MR_NONE, MR_ACCESS, MR_UPDATE };
-
typedef struct {
struct rw_semaphore mr_lock;
+#ifdef DEBUG
int mr_writer;
+#endif
} mrlock_t;
+#ifdef DEBUG
#define mrinit(mrp, name) \
do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0)
+#else
+#define mrinit(mrp, name) \
+ do { init_rwsem(&(mrp)->mr_lock); } while (0)
+#endif
+
#define mrlock_init(mrp, t,n,s) mrinit(mrp, n)
#define mrfree(mrp) do { } while (0)
-static inline void mraccess(mrlock_t *mrp)
-{
- down_read(&mrp->mr_lock);
-}
-
-static inline void mrupdate(mrlock_t *mrp)
-{
- down_write(&mrp->mr_lock);
- mrp->mr_writer = 1;
-}
-
static inline void mraccess_nested(mrlock_t *mrp, int subclass)
{
down_read_nested(&mrp->mr_lock, subclass);
@@ -51,10 +46,11 @@
static inline void mrupdate_nested(mrlock_t *mrp, int subclass)
{
down_write_nested(&mrp->mr_lock, subclass);
+#ifdef DEBUG
mrp->mr_writer = 1;
+#endif
}
-
static inline int mrtryaccess(mrlock_t *mrp)
{
return down_read_trylock(&mrp->mr_lock);
@@ -64,39 +60,31 @@
{
if (!down_write_trylock(&mrp->mr_lock))
return 0;
+#ifdef DEBUG
mrp->mr_writer = 1;
+#endif
return 1;
}
-static inline void mrunlock(mrlock_t *mrp)
+static inline void mrunlock_excl(mrlock_t *mrp)
{
- if (mrp->mr_writer) {
- mrp->mr_writer = 0;
- up_write(&mrp->mr_lock);
- } else {
- up_read(&mrp->mr_lock);
- }
+#ifdef DEBUG
+ mrp->mr_writer = 0;
+#endif
+ up_write(&mrp->mr_lock);
+}
+
+static inline void mrunlock_shared(mrlock_t *mrp)
+{
+ up_read(&mrp->mr_lock);
}
static inline void mrdemote(mrlock_t *mrp)
{
+#ifdef DEBUG
mrp->mr_writer = 0;
+#endif
downgrade_write(&mrp->mr_lock);
}
-#ifdef DEBUG
-/*
- * Debug-only routine, without some platform-specific asm code, we can
- * now only answer requests regarding whether we hold the lock for write
- * (reader state is outside our visibility, we only track writer state).
- * Note: means !ismrlocked would give false positives, so don't do that.
- */
-static inline int ismrlocked(mrlock_t *mrp, int type)
-{
- if (mrp && type == MR_UPDATE)
- return mrp->mr_writer;
- return 1;
-}
-#endif
-
#endif /* __XFS_SUPPORT_MRLOCK_H__ */
diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index 1ebd800..5e3b575 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -394,7 +394,7 @@
int error = 0;
xfs_bmbt_irec_t imap;
- ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE) != 0);
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
zero_offset = XFS_B_FSB_OFFSET(mp, isize);
if (zero_offset == 0) {
@@ -425,14 +425,14 @@
* out sync. We need to drop the ilock while we do this so we
* don't deadlock when the buffer cache calls back to us.
*/
- xfs_iunlock(ip, XFS_ILOCK_EXCL| XFS_EXTSIZE_RD);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
zero_len = mp->m_sb.sb_blocksize - zero_offset;
if (isize + zero_len > offset)
zero_len = offset - isize;
error = xfs_iozero(ip, isize, zero_len);
- xfs_ilock(ip, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
ASSERT(error >= 0);
return error;
}
@@ -465,8 +465,7 @@
int error = 0;
xfs_bmbt_irec_t imap;
- ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
- ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE));
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
ASSERT(offset > isize);
/*
@@ -475,8 +474,7 @@
*/
error = xfs_zero_last_block(ip, offset, isize);
if (error) {
- ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
- ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE));
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
return error;
}
@@ -507,8 +505,7 @@
error = xfs_bmapi(NULL, ip, start_zero_fsb, zero_count_fsb,
0, NULL, 0, &imap, &nimaps, NULL, NULL);
if (error) {
- ASSERT(ismrlocked(&ip->i_lock, MR_UPDATE));
- ASSERT(ismrlocked(&ip->i_iolock, MR_UPDATE));
+ ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
return error;
}
ASSERT(nimaps > 0);
@@ -532,7 +529,7 @@
* Drop the inode lock while we're doing the I/O.
* We'll still have the iolock to protect us.
*/
- xfs_iunlock(ip, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
@@ -548,13 +545,13 @@
start_zero_fsb = imap.br_startoff + imap.br_blockcount;
ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
- xfs_ilock(ip, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
}
return 0;
out_lock:
- xfs_ilock(ip, XFS_ILOCK_EXCL|XFS_EXTSIZE_RD);
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
ASSERT(error >= 0);
return error;
}