xfs: cleanup mapping tmpfs folios into the buffer cache

Directly assign b_addr based on the tmpfs folios without a detour
through pages, reuse the folio_put path used for non-tmpfs buffers
and replace all references to pages in comments with folios.

Partially based on a patch from Dave Chinner <dchinner@redhat.com>.

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

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 4aaa588330e4acb1f0f44dc7e37e77fccafb8f54..a7430fcd8301fed2f237fc0d9ff12f812833706e 100644 (file)
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -206,9 +206,7 @@ xfs_buf_free(
        if (!xfs_buftarg_is_mem(bp->b_target) && size >= PAGE_SIZE)
                mm_account_reclaimed_pages(howmany(size, PAGE_SHIFT));
 
-       if (xfs_buftarg_is_mem(bp->b_target))
-               xmbuf_unmap_page(bp);
-       else if (is_vmalloc_addr(bp->b_addr))
+       if (is_vmalloc_addr(bp->b_addr))
                vfree(bp->b_addr);
        else if (bp->b_flags & _XBF_KMEM)
                kfree(bp->b_addr);
@@ -275,7 +273,7 @@ xfs_buf_alloc_backing_mem(
        struct folio    *folio;
 
        if (xfs_buftarg_is_mem(bp->b_target))
-               return xmbuf_map_page(bp);
+               return xmbuf_map_backing_mem(bp);
 
        /* Assure zeroed buffer for non-read cases. */
        if (!(flags & XBF_READ))

diff --git a/fs/xfs/xfs_buf_mem.c b/fs/xfs/xfs_buf_mem.c
index b207754d2ee029965cabddf9eaf3f8d8db7cf56e..b4ffd80b7cb6325bfcb663d1d358dba11e42a6b0 100644 (file)
--- a/fs/xfs/xfs_buf_mem.c
+++ b/fs/xfs/xfs_buf_mem.c
@@ -74,7 +74,7 @@ xmbuf_alloc(
 
        /*
         * We don't want to bother with kmapping data during repair, so don't
-        * allow highmem pages to back this mapping.
+        * allow highmem folios to back this mapping.
         */
        mapping_set_gfp_mask(inode->i_mapping, GFP_KERNEL);
 
@@ -127,14 +127,13 @@ xmbuf_free(
        kfree(btp);
 }
 
-/* Directly map a shmem page into the buffer cache. */
+/* Directly map a shmem folio into the buffer cache. */
 int
-xmbuf_map_page(
+xmbuf_map_backing_mem(
        struct xfs_buf          *bp)
 {
        struct inode            *inode = file_inode(bp->b_target->bt_file);
        struct folio            *folio = NULL;
-       struct page             *page;
        loff_t                  pos = BBTOB(xfs_buf_daddr(bp));
        int                     error;
 
@@ -159,30 +158,17 @@ xmbuf_map_page(
                return -EIO;
        }
 
-       page = folio_file_page(folio, pos >> PAGE_SHIFT);
-
        /*
-        * Mark the page dirty so that it won't be reclaimed once we drop the
-        * (potentially last) reference in xmbuf_unmap_page.
+        * Mark the folio dirty so that it won't be reclaimed once we drop the
+        * (potentially last) reference in xfs_buf_free.
         */
-       set_page_dirty(page);
-       unlock_page(page);
+       folio_set_dirty(folio);
+       folio_unlock(folio);
 
-       bp->b_addr = page_address(page);
+       bp->b_addr = folio_address(folio);
        return 0;
 }
 
-/* Unmap a shmem page that was mapped into the buffer cache. */
-void
-xmbuf_unmap_page(
-       struct xfs_buf          *bp)
-{
-       ASSERT(xfs_buftarg_is_mem(bp->b_target));
-
-       put_page(virt_to_page(bp->b_addr));
-       bp->b_addr = NULL;
-}
-
 /* Is this a valid daddr within the buftarg? */
 bool
 xmbuf_verify_daddr(
@@ -196,7 +182,7 @@ xmbuf_verify_daddr(
        return daddr < (inode->i_sb->s_maxbytes >> BBSHIFT);
 }
 
-/* Discard the page backing this buffer. */
+/* Discard the folio backing this buffer. */
 static void
 xmbuf_stale(
        struct xfs_buf          *bp)
@@ -211,7 +197,7 @@ xmbuf_stale(
 }
 
 /*
- * Finalize a buffer -- discard the backing page if it's stale, or run the
+ * Finalize a buffer -- discard the backing folio if it's stale, or run the
  * write verifier to detect problems.
  */
 int

diff --git a/fs/xfs/xfs_buf_mem.h b/fs/xfs/xfs_buf_mem.h
index eed4a7b63232a376163af7f47a3af4860fdd2894..67d525cc15133add8126dbede87f3575658cc3cd 100644 (file)
--- a/fs/xfs/xfs_buf_mem.h
+++ b/fs/xfs/xfs_buf_mem.h
@@ -19,16 +19,14 @@ int xmbuf_alloc(struct xfs_mount *mp, const char *descr,
                struct xfs_buftarg **btpp);
 void xmbuf_free(struct xfs_buftarg *btp);
 
-int xmbuf_map_page(struct xfs_buf *bp);
-void xmbuf_unmap_page(struct xfs_buf *bp);
 bool xmbuf_verify_daddr(struct xfs_buftarg *btp, xfs_daddr_t daddr);
 void xmbuf_trans_bdetach(struct xfs_trans *tp, struct xfs_buf *bp);
 int xmbuf_finalize(struct xfs_buf *bp);
 #else
 # define xfs_buftarg_is_mem(...)       (false)
-# define xmbuf_map_page(...)           (-ENOMEM)
-# define xmbuf_unmap_page(...)         ((void)0)
 # define xmbuf_verify_daddr(...)       (false)
 #endif /* CONFIG_XFS_MEMORY_BUFS */
 
+int xmbuf_map_backing_mem(struct xfs_buf *bp);
+
 #endif /* __XFS_BUF_MEM_H__ */