xfs: convert open-coded xfs_rtword_t pointer accesses to helper

There are a bunch of places where we use open-coded logic to find a
pointer to an xfs_rtword_t within a rt bitmap buffer.  Convert all that
to helper functions for better type safety.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/xfs/libxfs/xfs_rtbitmap.c b/fs/xfs/libxfs/xfs_rtbitmap.c
index 63caad17dd8888d91914bf4e92cbe362bf9d66c2..cc3e70b7fbe566ffec39ada96d35c0cd744d30d4 100644 (file)
--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -103,7 +103,6 @@ xfs_rtfind_back(
        int             bit;            /* bit number in the word */
        xfs_fileoff_t   block;          /* bitmap block number */
        struct xfs_buf  *bp;            /* buf for the block */
-       xfs_rtword_t    *bufp;          /* starting word in buffer */
        int             error;          /* error value */
        xfs_rtxnum_t    firstbit;       /* first useful bit in the word */
        xfs_rtxnum_t    i;              /* current bit number rel. to start */
@@ -121,12 +120,12 @@ xfs_rtfind_back(
        if (error) {
                return error;
        }
-       bufp = bp->b_addr;
+
        /*
         * Get the first word's index & point to it.
         */
        word = xfs_rtx_to_rbmword(mp, start);
-       b = &bufp[word];
+       b = xfs_rbmblock_wordptr(bp, word);
        bit = (int)(start & (XFS_NBWORD - 1));
        len = start - limit + 1;
        /*
@@ -173,9 +172,9 @@ xfs_rtfind_back(
                        if (error) {
                                return error;
                        }
-                       bufp = bp->b_addr;
+
                        word = mp->m_blockwsize - 1;
-                       b = &bufp[word];
+                       b = xfs_rbmblock_wordptr(bp, word);
                } else {
                        /*
                         * Go on to the previous word in the buffer.
@@ -219,9 +218,9 @@ xfs_rtfind_back(
                        if (error) {
                                return error;
                        }
-                       bufp = bp->b_addr;
+
                        word = mp->m_blockwsize - 1;
-                       b = &bufp[word];
+                       b = xfs_rbmblock_wordptr(bp, word);
                } else {
                        /*
                         * Go on to the previous word in the buffer.
@@ -278,7 +277,6 @@ xfs_rtfind_forw(
        int             bit;            /* bit number in the word */
        xfs_fileoff_t   block;          /* bitmap block number */
        struct xfs_buf  *bp;            /* buf for the block */
-       xfs_rtword_t    *bufp;          /* starting word in buffer */
        int             error;          /* error value */
        xfs_rtxnum_t    i;              /* current bit number rel. to start */
        xfs_rtxnum_t    lastbit;        /* last useful bit in the word */
@@ -296,12 +294,12 @@ xfs_rtfind_forw(
        if (error) {
                return error;
        }
-       bufp = bp->b_addr;
+
        /*
         * Get the first word's index & point to it.
         */
        word = xfs_rtx_to_rbmword(mp, start);
-       b = &bufp[word];
+       b = xfs_rbmblock_wordptr(bp, word);
        bit = (int)(start & (XFS_NBWORD - 1));
        len = limit - start + 1;
        /*
@@ -347,8 +345,9 @@ xfs_rtfind_forw(
                        if (error) {
                                return error;
                        }
-                       b = bufp = bp->b_addr;
+
                        word = 0;
+                       b = xfs_rbmblock_wordptr(bp, word);
                } else {
                        /*
                         * Go on to the previous word in the buffer.
@@ -392,8 +391,9 @@ xfs_rtfind_forw(
                        if (error) {
                                return error;
                        }
-                       b = bufp = bp->b_addr;
+
                        word = 0;
+                       b = xfs_rbmblock_wordptr(bp, word);
                } else {
                        /*
                         * Go on to the next word in the buffer.
@@ -541,7 +541,6 @@ xfs_rtmodify_range(
        int             bit;            /* bit number in the word */
        xfs_fileoff_t   block;          /* bitmap block number */
        struct xfs_buf  *bp;            /* buf for the block */
-       xfs_rtword_t    *bufp;          /* starting word in buffer */
        int             error;          /* error value */
        xfs_rtword_t    *first;         /* first used word in the buffer */
        int             i;              /* current bit number rel. to start */
@@ -560,12 +559,12 @@ xfs_rtmodify_range(
        if (error) {
                return error;
        }
-       bufp = bp->b_addr;
+
        /*
         * Compute the starting word's address, and starting bit.
         */
        word = xfs_rtx_to_rbmword(mp, start);
-       first = b = &bufp[word];
+       first = b = xfs_rbmblock_wordptr(bp, word);
        bit = (int)(start & (XFS_NBWORD - 1));
        /*
         * 0 (allocated) => all zeroes; 1 (free) => all ones.
@@ -599,14 +598,15 @@ xfs_rtmodify_range(
                         * Get the next one.
                         */
                        xfs_trans_log_buf(tp, bp,
-                               (uint)((char *)first - (char *)bufp),
-                               (uint)((char *)b - (char *)bufp));
+                               (uint)((char *)first - (char *)bp->b_addr),
+                               (uint)((char *)b - (char *)bp->b_addr));
                        error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
                        if (error) {
                                return error;
                        }
-                       first = b = bufp = bp->b_addr;
+
                        word = 0;
+                       first = b = xfs_rbmblock_wordptr(bp, word);
                } else {
                        /*
                         * Go on to the next word in the buffer
@@ -639,14 +639,15 @@ xfs_rtmodify_range(
                         * Get the next one.
                         */
                        xfs_trans_log_buf(tp, bp,
-                               (uint)((char *)first - (char *)bufp),
-                               (uint)((char *)b - (char *)bufp));
+                               (uint)((char *)first - (char *)bp->b_addr),
+                               (uint)((char *)b - (char *)bp->b_addr));
                        error = xfs_rtbuf_get(mp, tp, ++block, 0, &bp);
                        if (error) {
                                return error;
                        }
-                       first = b = bufp = bp->b_addr;
+
                        word = 0;
+                       first = b = xfs_rbmblock_wordptr(bp, word);
                } else {
                        /*
                         * Go on to the next word in the buffer
@@ -676,8 +677,9 @@ xfs_rtmodify_range(
         * Log any remaining changed bytes.
         */
        if (b > first)
-               xfs_trans_log_buf(tp, bp, (uint)((char *)first - (char *)bufp),
-                       (uint)((char *)b - (char *)bufp - 1));
+               xfs_trans_log_buf(tp, bp,
+                       (uint)((char *)first - (char *)bp->b_addr),
+                       (uint)((char *)b - (char *)bp->b_addr - 1));
        return 0;
 }
 
@@ -775,7 +777,6 @@ xfs_rtcheck_range(
        int             bit;            /* bit number in the word */
        xfs_fileoff_t   block;          /* bitmap block number */
        struct xfs_buf  *bp;            /* buf for the block */
-       xfs_rtword_t    *bufp;          /* starting word in buffer */
        int             error;          /* error value */
        xfs_rtxnum_t    i;              /* current bit number rel. to start */
        xfs_rtxnum_t    lastbit;        /* last useful bit in word */
@@ -794,12 +795,12 @@ xfs_rtcheck_range(
        if (error) {
                return error;
        }
-       bufp = bp->b_addr;
+
        /*
         * Compute the starting word's address, and starting bit.
         */
        word = xfs_rtx_to_rbmword(mp, start);
-       b = &bufp[word];
+       b = xfs_rbmblock_wordptr(bp, word);
        bit = (int)(start & (XFS_NBWORD - 1));
        /*
         * 0 (allocated) => all zero's; 1 (free) => all one's.
@@ -845,8 +846,9 @@ xfs_rtcheck_range(
                        if (error) {
                                return error;
                        }
-                       b = bufp = bp->b_addr;
+
                        word = 0;
+                       b = xfs_rbmblock_wordptr(bp, word);
                } else {
                        /*
                         * Go on to the next word in the buffer.
@@ -891,8 +893,9 @@ xfs_rtcheck_range(
                        if (error) {
                                return error;
                        }
-                       b = bufp = bp->b_addr;
+
                        word = 0;
+                       b = xfs_rbmblock_wordptr(bp, word);
                } else {
                        /*
                         * Go on to the next word in the buffer.

diff --git a/fs/xfs/libxfs/xfs_rtbitmap.h b/fs/xfs/libxfs/xfs_rtbitmap.h
index a382b38c6c30dcc6350ae1b1025842f28cb433e8..3252ed217a6a63cdfa2ccc50b53959eeb9c93298 100644 (file)
--- a/fs/xfs/libxfs/xfs_rtbitmap.h
+++ b/fs/xfs/libxfs/xfs_rtbitmap.h
@@ -158,6 +158,17 @@ xfs_rbmblock_to_rtx(
        return rbmoff << mp->m_blkbit_log;
 }
 
+/* Return a pointer to a bitmap word within a rt bitmap block. */
+static inline xfs_rtword_t *
+xfs_rbmblock_wordptr(
+       struct xfs_buf          *bp,
+       unsigned int            index)
+{
+       xfs_rtword_t            *words = bp->b_addr;
+
+       return words + index;
+}
+
 /*
  * Functions for walking free space rtextents in the realtime bitmap.
  */