mm: close PageTail race

[linux.git] / drivers / block / floppy.c

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 000abe2f105c60f06d5fac31a2a4889cddd22b15..2023043ce7c0e94b0e3c3618eb0787a9ad5ddb73 100644 (file)
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -2351,7 +2351,7 @@ static void rw_interrupt(void)
 /* Compute maximal contiguous buffer size. */
 static int buffer_chain_size(void)
 {
-       struct bio_vec *bv;
+       struct bio_vec bv;
        int size;
        struct req_iterator iter;
        char *base;
@@ -2360,10 +2360,10 @@ static int buffer_chain_size(void)
        size = 0;
 
        rq_for_each_segment(bv, current_req, iter) {
-               if (page_address(bv->bv_page) + bv->bv_offset != base + size)
+               if (page_address(bv.bv_page) + bv.bv_offset != base + size)
                        break;
 
-               size += bv->bv_len;
+               size += bv.bv_len;
        }
 
        return size >> 9;
@@ -2389,7 +2389,7 @@ static int transfer_size(int ssize, int max_sector, int max_size)
 static void copy_buffer(int ssize, int max_sector, int max_sector_2)
 {
        int remaining;          /* number of transferred 512-byte sectors */
-       struct bio_vec *bv;
+       struct bio_vec bv;
        char *buffer;
        char *dma_buffer;
        int size;
@@ -2427,10 +2427,10 @@ static void copy_buffer(int ssize, int max_sector, int max_sector_2)
                if (!remaining)
                        break;
 
-               size = bv->bv_len;
+               size = bv.bv_len;
                SUPBOUND(size, remaining);
 
-               buffer = page_address(bv->bv_page) + bv->bv_offset;
+               buffer = page_address(bv.bv_page) + bv.bv_offset;
                if (dma_buffer + size >
                    floppy_track_buffer + (max_buffer_sectors << 10) ||
                    dma_buffer < floppy_track_buffer) {
@@ -3691,9 +3691,12 @@ static int floppy_open(struct block_device *bdev, fmode_t mode)
        if (!(mode & FMODE_NDELAY)) {
                if (mode & (FMODE_READ|FMODE_WRITE)) {
                        UDRS->last_checked = 0;
+                       clear_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags);
                        check_disk_change(bdev);
                        if (test_bit(FD_DISK_CHANGED_BIT, &UDRS->flags))
                                goto out;
+                       if (test_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags))
+                               goto out;
                }
                res = -EROFS;
                if ((mode & FMODE_WRITE) &&
@@ -3746,17 +3749,29 @@ static unsigned int floppy_check_events(struct gendisk *disk,
  * a disk in the drive, and whether that disk is writable.
  */
 
-static void floppy_rb0_complete(struct bio *bio, int err)
+struct rb0_cbdata {
+       int drive;
+       struct completion complete;
+};
+
+static void floppy_rb0_cb(struct bio *bio, int err)
 {
-       complete((struct completion *)bio->bi_private);
+       struct rb0_cbdata *cbdata = (struct rb0_cbdata *)bio->bi_private;
+       int drive = cbdata->drive;
+
+       if (err) {
+               pr_info("floppy: error %d while reading block 0", err);
+               set_bit(FD_OPEN_SHOULD_FAIL_BIT, &UDRS->flags);
+       }
+       complete(&cbdata->complete);
 }
 
-static int __floppy_read_block_0(struct block_device *bdev)
+static int __floppy_read_block_0(struct block_device *bdev, int drive)
 {
        struct bio bio;
        struct bio_vec bio_vec;
-       struct completion complete;
        struct page *page;
+       struct rb0_cbdata cbdata;
        size_t size;
 
        page = alloc_page(GFP_NOIO);
@@ -3769,23 +3784,26 @@ static int __floppy_read_block_0(struct block_device *bdev)
        if (!size)
                size = 1024;
 
+       cbdata.drive = drive;
+
        bio_init(&bio);
        bio.bi_io_vec = &bio_vec;
        bio_vec.bv_page = page;
        bio_vec.bv_len = size;
        bio_vec.bv_offset = 0;
        bio.bi_vcnt = 1;
-       bio.bi_size = size;
+       bio.bi_iter.bi_size = size;
        bio.bi_bdev = bdev;
-       bio.bi_sector = 0;
+       bio.bi_iter.bi_sector = 0;
        bio.bi_flags = (1 << BIO_QUIET);
-       init_completion(&complete);
-       bio.bi_private = &complete;
-       bio.bi_end_io = floppy_rb0_complete;
+       bio.bi_private = &cbdata;
+       bio.bi_end_io = floppy_rb0_cb;
 
        submit_bio(READ, &bio);
        process_fd_request();
-       wait_for_completion(&complete);
+
+       init_completion(&cbdata.complete);
+       wait_for_completion(&cbdata.complete);
 
        __free_page(page);
 
@@ -3827,7 +3845,7 @@ static int floppy_revalidate(struct gendisk *disk)
                        UDRS->generation++;
                if (drive_no_geom(drive)) {
                        /* auto-sensing */
-                       res = __floppy_read_block_0(opened_bdev[drive]);
+                       res = __floppy_read_block_0(opened_bdev[drive], drive);
                } else {
                        if (cf)
                                poll_drive(false, FD_RAW_NEED_DISK);