fs/direct-io.c: calculate fs_count correctly in get_more_blocks()

[~andy/linux] / fs / direct-io.c

diff --git a/fs/direct-io.c b/fs/direct-io.c
index d740ab67ff6e1bd581218fb149eb7a58c40fa3f3..389863f59cda384ecea6aae6ffa31c206fff4bac 100644 (file)
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -580,9 +580,8 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
 {
        int ret;
        sector_t fs_startblk;   /* Into file, in filesystem-sized blocks */
+       sector_t fs_endblk;     /* Into file, in filesystem-sized blocks */
        unsigned long fs_count; /* Number of filesystem-sized blocks */
-       unsigned long dio_count;/* Number of dio_block-sized blocks */
-       unsigned long blkmask;
        int create;
 
        /*
@@ -593,11 +592,9 @@ static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
        if (ret == 0) {
                BUG_ON(sdio->block_in_file >= sdio->final_block_in_request);
                fs_startblk = sdio->block_in_file >> sdio->blkfactor;
-               dio_count = sdio->final_block_in_request - sdio->block_in_file;
-               fs_count = dio_count >> sdio->blkfactor;
-               blkmask = (1 << sdio->blkfactor) - 1;
-               if (dio_count & blkmask)        
-                       fs_count++;
+               fs_endblk = (sdio->final_block_in_request - 1) >>
+                                       sdio->blkfactor;
+               fs_count = fs_endblk - fs_startblk + 1;
 
                map_bh->b_state = 0;
                map_bh->b_size = fs_count << dio->inode->i_blkbits;