[PATCH 03/24] xfs: mark inode buffers in cache

Dave Chinner
2020-05-22T03:50:40Z

From: Dave Chinner <dchinner@redhat.com>

Inode buffers always have write IO callbacks, so by marking them
directly we can avoid needing to attach ->b_iodone functions to
them. This avoids an indirect call, and makes future modifications
much simpler.

This is largely a rearrangement of the code at this point - no IO
completion functionality changes at this point, just how the
code is run is modified.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
fs/xfs/xfs_buf.c | 18 +++++++++++++-----
fs/xfs/xfs_buf.h | 39 ++++++++++++++++++++++++++-------------
fs/xfs/xfs_buf_item.c | 42 +++++++++++++++++++++++++++++++-----------
fs/xfs/xfs_buf_item.h | 1 +
fs/xfs/xfs_inode.c | 2 +-
fs/xfs/xfs_trans_buf.c | 3 +++
6 files changed, 75 insertions(+), 30 deletions(-)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 9c2fbb6bbf89d..6105b97028d6a 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -14,6 +14,8 @@
#include "xfs_mount.h"
#include "xfs_trace.h"
#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_buf_item.h"
#include "xfs_errortag.h"
#include "xfs_error.h"

@@ -1202,12 +1204,18 @@ xfs_buf_ioend(
bp->b_flags |= XBF_DONE;
}

- if (bp->b_iodone)
+ /* inodes always have a callback on write */
+ if (!read && (bp->b_flags & _XBF_INODES)) {
+ xfs_buf_inode_iodone(bp);
+ return;
+ }
+
+ if (bp->b_iodone) {
(*(bp->b_iodone))(bp);
- else if (bp->b_flags & XBF_ASYNC)
- xfs_buf_relse(bp);
- else
- complete(&bp->b_iowait);
+ return;
+ }
+
+ xfs_buf_ioend_finish(bp);
}

static void
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 050c53b739e24..b3e5d653d09f1 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -30,15 +30,19 @@
#define XBF_STALE (1 << 6) /* buffer has been staled, do not find it */
#define XBF_WRITE_FAIL (1 << 7) /* async writes have failed on this buffer */

-/* flags used only as arguments to access routines */
-#define XBF_TRYLOCK (1 << 16)/* lock requested, but do not wait */
-#define XBF_UNMAPPED (1 << 17)/* do not map the buffer */
+/* buffer type flags for write callbacks */
+#define _XBF_INODES (1 << 16)/* inode buffer */

/* flags used only internally */
#define _XBF_PAGES (1 << 20)/* backed by refcounted pages */
#define _XBF_KMEM (1 << 21)/* backed by heap memory */
#define _XBF_DELWRI_Q (1 << 22)/* buffer on a delwri queue */

+/* flags used only as arguments to access routines */
+#define XBF_TRYLOCK (1 << 30)/* lock requested, but do not wait */
+#define XBF_UNMAPPED (1 << 31)/* do not map the buffer */
+
+
typedef unsigned int xfs_buf_flags_t;

#define XFS_BUF_FLAGS \
@@ -50,12 +54,13 @@ typedef unsigned int xfs_buf_flags_t;
{ XBF_DONE, "DONE" }, \
{ XBF_STALE, "STALE" }, \
{ XBF_WRITE_FAIL, "WRITE_FAIL" }, \
- { XBF_TRYLOCK, "TRYLOCK" }, /* should never be set */\
- { XBF_UNMAPPED, "UNMAPPED" }, /* ditto */\
+ { _XBF_INODES, "INODES" }, \
{ _XBF_PAGES, "PAGES" }, \
{ _XBF_KMEM, "KMEM" }, \
- { _XBF_DELWRI_Q, "DELWRI_Q" }
-
+ { _XBF_DELWRI_Q, "DELWRI_Q" }, \
+ /* The following interface flags should never be set */ \
+ { XBF_TRYLOCK, "TRYLOCK" }, \
+ { XBF_UNMAPPED, "UNMAPPED" }

/*
* Internal state flags.
@@ -257,9 +262,23 @@ extern void xfs_buf_unlock(xfs_buf_t *);
#define xfs_buf_islocked(bp) \
((bp)->b_sema.count <= 0)

+static inline void xfs_buf_relse(xfs_buf_t *bp)
+{
+ xfs_buf_unlock(bp);
+ xfs_buf_rele(bp);
+}
+
/* Buffer Read and Write Routines */
extern int xfs_bwrite(struct xfs_buf *bp);
extern void xfs_buf_ioend(struct xfs_buf *bp);
+static inline void xfs_buf_ioend_finish(struct xfs_buf *bp)
+{
+ if (bp->b_flags & XBF_ASYNC)
+ xfs_buf_relse(bp);
+ else
+ complete(&bp->b_iowait);
+}
+
extern void __xfs_buf_ioerror(struct xfs_buf *bp, int error,
xfs_failaddr_t failaddr);
#define xfs_buf_ioerror(bp, err) __xfs_buf_ioerror((bp), (err), __this_address)
@@ -324,12 +343,6 @@ static inline int xfs_buf_ispinned(struct xfs_buf *bp)
return atomic_read(&bp->b_pin_count);
}

-static inline void xfs_buf_relse(xfs_buf_t *bp)
-{
- xfs_buf_unlock(bp);
- xfs_buf_rele(bp);
-}
-
static inline int
xfs_buf_verify_cksum(struct xfs_buf *bp, unsigned long cksum_offset)
{
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index 9e75e8d6042ec..8659cf4282a64 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -1158,20 +1158,15 @@ xfs_buf_iodone_callback_error(
return false;
}

-/*
- * This is the iodone() function for buffers which have had callbacks attached
- * to them by xfs_buf_attach_iodone(). We need to iterate the items on the
- * callback list, mark the buffer as having no more callbacks and then push the
- * buffer through IO completion processing.
- */
-void
-xfs_buf_iodone_callbacks(
+static void
+xfs_buf_run_callbacks(
struct xfs_buf *bp)
{
+
/*
- * If there is an error, process it. Some errors require us
- * to run callbacks after failure processing is done so we
- * detect that and take appropriate action.
+ * If there is an error, process it. Some errors require us to run
+ * callbacks after failure processing is done so we detect that and take
+ * appropriate action.
*/
if (bp->b_error && xfs_buf_iodone_callback_error(bp))
return;
@@ -1188,9 +1183,34 @@ xfs_buf_iodone_callbacks(
bp->b_log_item = NULL;
list_del_init(&bp->b_li_list);
bp->b_iodone = NULL;
+}
+
+/*
+ * This is the iodone() function for buffers which have had callbacks attached
+ * to them by xfs_buf_attach_iodone(). We need to iterate the items on the
+ * callback list, mark the buffer as having no more callbacks and then push the
+ * buffer through IO completion processing.
+ */
+void
+xfs_buf_iodone_callbacks(
+ struct xfs_buf *bp)
+{
+ xfs_buf_run_callbacks(bp);
xfs_buf_ioend(bp);
}

+/*
+ * Inode buffer iodone callback function.
+ */
+void
+xfs_buf_inode_iodone(
+ struct xfs_buf *bp)
+{
+ xfs_buf_run_callbacks(bp);
+ xfs_buf_ioend_finish(bp);
+}
+
+
/*
* This is the iodone() function for buffers which have been
* logged. It is called when they are eventually flushed out.
diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
index c9c57e2da9327..a342933ad9b8d 100644
--- a/fs/xfs/xfs_buf_item.h
+++ b/fs/xfs/xfs_buf_item.h
@@ -59,6 +59,7 @@ void xfs_buf_attach_iodone(struct xfs_buf *,
struct xfs_log_item *);
void xfs_buf_iodone_callbacks(struct xfs_buf *);
void xfs_buf_iodone(struct xfs_buf *, struct xfs_log_item *);
+void xfs_buf_inode_iodone(struct xfs_buf *);
bool xfs_buf_log_check_iovec(struct xfs_log_iovec *iovec);

extern kmem_zone_t *xfs_buf_item_zone;
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 57781c0dbbec5..607c9d9bb2b40 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3841,13 +3841,13 @@ xfs_iflush_int(
* completion on the buffer to remove the inode from the AIL and release
* the flush lock.
*/
+ bp->b_flags |= _XBF_INODES;
xfs_buf_attach_iodone(bp, xfs_iflush_done, &iip->ili_item);

/* generate the checksum. */
xfs_dinode_calc_crc(mp, dip);

ASSERT(!list_empty(&bp->b_li_list));
- ASSERT(bp->b_iodone != NULL);
return error;
}

diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 08174ffa21189..552d0869aa0fe 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -626,6 +626,7 @@ xfs_trans_inode_buf(
ASSERT(atomic_read(&bip->bli_refcount) > 0);

bip->bli_flags |= XFS_BLI_INODE_BUF;
+ bp->b_flags |= _XBF_INODES;
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
}

@@ -651,6 +652,7 @@ xfs_trans_stale_inode_buf(

bip->bli_flags |= XFS_BLI_STALE_INODE;
bip->bli_item.li_cb = xfs_buf_iodone;
+ bp->b_flags |= _XBF_INODES;
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
}

@@ -675,6 +677,7 @@ xfs_trans_inode_alloc_buf(
ASSERT(atomic_read(&bip->bli_refcount) > 0);

bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF;
+ bp->b_flags |= _XBF_INODES;
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_DINO_BUF);
}

--
2.26.2.761.g0e0b3e54be