xfs
[Top] [All Lists]

[PATCH 37/37] xfs: make XBF_MAPPED the default behaviour

To: xfs@xxxxxxxxxxx
Subject: [PATCH 37/37] xfs: make XBF_MAPPED the default behaviour
From: Dave Chinner <david@xxxxxxxxxxxxx>
Date: Mon, 23 Apr 2012 15:59:07 +1000
In-reply-to: <1335160747-17254-1-git-send-email-david@xxxxxxxxxxxxx>
References: <1335160747-17254-1-git-send-email-david@xxxxxxxxxxxxx>
From: Dave Chinner <dchinner@xxxxxxxxxx>

Rather than specifying XBF_MAPPED for almost all buffers, introduce
XBF_UNMAPPED for the couple of users that use unmapped buffers.

Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
---
 fs/xfs/xfs_buf.c         |   28 +++++++++++++---------------
 fs/xfs/xfs_buf.h         |    4 ++--
 fs/xfs/xfs_fsops.c       |   10 +++++-----
 fs/xfs/xfs_inode.c       |    1 +
 fs/xfs/xfs_log_recover.c |    4 ++--
 fs/xfs/xfs_trans_buf.c   |    6 ------
 fs/xfs/xfs_vnodeops.c    |    3 +--
 7 files changed, 24 insertions(+), 32 deletions(-)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index b2795ba..172d3cc 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -65,11 +65,11 @@ xfs_buf_is_vmapped(
        /*
         * Return true if the buffer is vmapped.
         *
-        * The XBF_MAPPED flag is set if the buffer should be mapped, but the
-        * code is clever enough to know it doesn't have to map a single page,
-        * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1.
+        * b_addr is null if the buffer is not mapped, but the code is clever
+        * enough to know it doesn't have to map a single page, so the check has
+        * to be both for b_addr and bp->b_page_count > 1.
         */
-       return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1;
+       return bp->b_addr && bp->b_page_count > 1;
 }
 
 static inline int
@@ -181,7 +181,7 @@ xfs_buf_alloc(
         * We don't want certain flags to appear in b_flags unless they are
         * specifically set by later operations on the buffer.
         */
-       flags &= ~(XBF_MAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD);
+       flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD);
 
        atomic_set(&bp->b_hold, 1);
        atomic_set(&bp->b_lru_ref, 1);
@@ -329,7 +329,7 @@ xfs_buf_allocate_memory(
                bp->b_pages = bp->b_page_array;
                bp->b_pages[0] = virt_to_page(bp->b_addr);
                bp->b_page_count = 1;
-               bp->b_flags |= XBF_MAPPED | _XBF_KMEM;
+               bp->b_flags |= _XBF_KMEM;
                return 0;
        }
 
@@ -399,8 +399,9 @@ _xfs_buf_map_pages(
        if (bp->b_page_count == 1) {
                /* A single page buffer is always mappable */
                bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset;
-               bp->b_flags |= XBF_MAPPED;
-       } else if (flags & XBF_MAPPED) {
+       } else if (flags & XBF_UNMAPPED) {
+               bp->b_addr = NULL;
+       } else {
                int retried = 0;
 
                do {
@@ -414,7 +415,6 @@ _xfs_buf_map_pages(
                if (!bp->b_addr)
                        return -ENOMEM;
                bp->b_addr += bp->b_offset;
-               bp->b_flags |= XBF_MAPPED;
        }
 
        return 0;
@@ -520,7 +520,7 @@ found:
         */
        if (bp->b_flags & XBF_STALE) {
                ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0);
-               bp->b_flags &= XBF_MAPPED | _XBF_KMEM | _XBF_PAGES;
+               bp->b_flags &= _XBF_KMEM | _XBF_PAGES;
        }
 
        trace_xfs_buf_find(bp, flags, _RET_IP_);
@@ -575,7 +575,7 @@ xfs_buf_get(
        bp->b_io_length = bp->b_length;
 
 found:
-       if (!(bp->b_flags & XBF_MAPPED)) {
+       if (!bp->b_addr) {
                error = _xfs_buf_map_pages(bp, flags);
                if (unlikely(error)) {
                        xfs_warn(target->bt_mount,
@@ -707,7 +707,6 @@ xfs_buf_set_empty(
        bp->b_length = numblks;
        bp->b_io_length = numblks;
        bp->b_bn = XFS_BUF_DADDR_NULL;
-       bp->b_flags &= ~XBF_MAPPED;
 }
 
 static inline struct page *
@@ -759,7 +758,6 @@ xfs_buf_associate_memory(
 
        bp->b_io_length = BTOBB(len);
        bp->b_length = BTOBB(buflen);
-       bp->b_flags |= XBF_MAPPED;
 
        return 0;
 }
@@ -790,7 +788,7 @@ xfs_buf_get_uncached(
        }
        bp->b_flags |= _XBF_PAGES;
 
-       error = _xfs_buf_map_pages(bp, XBF_MAPPED);
+       error = _xfs_buf_map_pages(bp, 0);
        if (unlikely(error)) {
                xfs_warn(target->bt_mount,
                        "%s: failed to map pages\n", __func__);
@@ -1287,7 +1285,7 @@ xfs_buf_offset(
 {
        struct page             *page;
 
-       if (bp->b_flags & XBF_MAPPED)
+       if (bp->b_addr)
                return bp->b_addr + offset;
 
        offset += bp->b_offset;
diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h
index 846dee3..7f1d139 100644
--- a/fs/xfs/xfs_buf.h
+++ b/fs/xfs/xfs_buf.h
@@ -41,7 +41,6 @@ typedef enum {
 #define XBF_READ       (1 << 0) /* buffer intended for reading from device */
 #define XBF_WRITE      (1 << 1) /* buffer intended for writing to device */
 #define XBF_READ_AHEAD (1 << 2) /* asynchronous read-ahead */
-#define XBF_MAPPED     (1 << 3) /* buffer mapped (b_addr valid) */
 #define XBF_ASYNC      (1 << 4) /* initiator will not wait for completion */
 #define XBF_DONE       (1 << 5) /* all pages in the buffer uptodate */
 #define XBF_STALE      (1 << 6) /* buffer has been staled, do not find it */
@@ -53,6 +52,7 @@ typedef enum {
 
 /* 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 */
 
 /* flags used only internally */
 #define _XBF_PAGES     (1 << 20)/* backed by refcounted pages */
@@ -65,7 +65,6 @@ typedef unsigned int xfs_buf_flags_t;
        { XBF_READ,             "READ" }, \
        { XBF_WRITE,            "WRITE" }, \
        { XBF_READ_AHEAD,       "READ_AHEAD" }, \
-       { XBF_MAPPED,           "MAPPED" }, \
        { XBF_ASYNC,            "ASYNC" }, \
        { XBF_DONE,             "DONE" }, \
        { XBF_STALE,            "STALE" }, \
@@ -73,6 +72,7 @@ typedef unsigned int xfs_buf_flags_t;
        { XBF_FUA,              "FUA" }, \
        { XBF_FLUSH,            "FLUSH" }, \
        { XBF_TRYLOCK,          "TRYLOCK" },    /* should never be set */\
+       { XBF_UNMAPPED,         "UNMAPPED" },   /* ditto */\
        { _XBF_PAGES,           "PAGES" }, \
        { _XBF_KMEM,            "KMEM" }, \
        { _XBF_DELWRI_Q,        "DELWRI_Q" }
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 75593d9..c25b094 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -190,7 +190,7 @@ xfs_growfs_data_private(
                 */
                bp = xfs_buf_get(mp->m_ddev_targp,
                                 XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
-                                XFS_FSS_TO_BB(mp, 1), XBF_MAPPED);
+                                XFS_FSS_TO_BB(mp, 1), 0);
                if (!bp) {
                        error = ENOMEM;
                        goto error0;
@@ -227,7 +227,7 @@ xfs_growfs_data_private(
                 */
                bp = xfs_buf_get(mp->m_ddev_targp,
                                 XFS_AG_DADDR(mp, agno, XFS_AGI_DADDR(mp)),
-                                XFS_FSS_TO_BB(mp, 1), XBF_MAPPED);
+                                XFS_FSS_TO_BB(mp, 1), 0);
                if (!bp) {
                        error = ENOMEM;
                        goto error0;
@@ -256,7 +256,7 @@ xfs_growfs_data_private(
                 */
                bp = xfs_buf_get(mp->m_ddev_targp,
                                 XFS_AGB_TO_DADDR(mp, agno, XFS_BNO_BLOCK(mp)),
-                                BTOBB(mp->m_sb.sb_blocksize), XBF_MAPPED);
+                                BTOBB(mp->m_sb.sb_blocksize), 0);
                if (!bp) {
                        error = ENOMEM;
                        goto error0;
@@ -282,7 +282,7 @@ xfs_growfs_data_private(
                 */
                bp = xfs_buf_get(mp->m_ddev_targp,
                                 XFS_AGB_TO_DADDR(mp, agno, XFS_CNT_BLOCK(mp)),
-                                BTOBB(mp->m_sb.sb_blocksize), XBF_MAPPED);
+                                BTOBB(mp->m_sb.sb_blocksize), 0);
                if (!bp) {
                        error = ENOMEM;
                        goto error0;
@@ -309,7 +309,7 @@ xfs_growfs_data_private(
                 */
                bp = xfs_buf_get(mp->m_ddev_targp,
                                 XFS_AGB_TO_DADDR(mp, agno, XFS_IBT_BLOCK(mp)),
-                                BTOBB(mp->m_sb.sb_blocksize), XBF_MAPPED);
+                                BTOBB(mp->m_sb.sb_blocksize), 0);
                if (!bp) {
                        error = ENOMEM;
                        goto error0;
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 72ec1a4..a59eea0 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -150,6 +150,7 @@ xfs_imap_to_bp(
        int             ni;
        xfs_buf_t       *bp;
 
+       buf_flags |= XBF_UNMAPPED;
        error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp, imap->im_blkno,
                                   (int)imap->im_len, buf_flags, &bp);
        if (error) {
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 574e2e9..d7abe5f 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -2127,8 +2127,8 @@ xlog_recover_buffer_pass2(
        trace_xfs_log_recover_buf_recover(log, buf_f);
 
        buf_flags = 0;
-       if (!(buf_f->blf_flags & XFS_BLF_INODE_BUF))
-               buf_flags |= XBF_MAPPED;
+       if (buf_f->blf_flags & XFS_BLF_INODE_BUF)
+               buf_flags |= XBF_UNMAPPED;
 
        bp = xfs_buf_read(mp->m_ddev_targp, buf_f->blf_blkno, buf_f->blf_len,
                          buf_flags);
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index d250afa..21c5a5e 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -138,9 +138,6 @@ xfs_trans_get_buf(xfs_trans_t       *tp,
        xfs_buf_t               *bp;
        xfs_buf_log_item_t      *bip;
 
-       if (flags == 0)
-               flags = XBF_MAPPED;
-
        /*
         * Default to a normal get_buf() call if the tp is NULL.
         */
@@ -264,9 +261,6 @@ xfs_trans_read_buf(
 
        *bpp = NULL;
 
-       if (flags == 0)
-               flags = XBF_MAPPED;
-
        /*
         * Default to a normal get_buf() call if the tp is NULL.
         */
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 5b3f5b1..82b000f 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -79,8 +79,7 @@ xfs_readlink_bmap(
                d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
                byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
 
-               bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt),
-                                 XBF_MAPPED);
+               bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0);
                if (!bp)
                        return XFS_ERROR(ENOMEM);
                error = bp->b_error;
-- 
1.7.9.5

<Prev in Thread] Current Thread [Next in Thread>