bio: return EINTR if copying to user space got interrupted

[pandora-kernel.git] / fs / bio.c

diff --git a/fs/bio.c b/fs/bio.c
index 41c93c7..55b5188 100644 (file)
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -337,7 +337,7 @@ static void bio_fs_destructor(struct bio *bio)
  *     RETURNS:
  *     Pointer to new bio on success, NULL on failure.
  */
-struct bio *bio_alloc(gfp_t gfp_mask, int nr_iovecs)
+struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 {
        struct bio *bio = bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
 
@@ -365,7 +365,7 @@ static void bio_kmalloc_destructor(struct bio *bio)
  *   %__GFP_WAIT, the allocation is guaranteed to succeed.
  *
  **/
-struct bio *bio_kmalloc(gfp_t gfp_mask, int nr_iovecs)
+struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
 {
        struct bio *bio;
 
@@ -507,11 +507,12 @@ int bio_get_nr_vecs(struct block_device *bdev)
        struct request_queue *q = bdev_get_queue(bdev);
        int nr_pages;
 
-       nr_pages = ((queue_max_sectors(q) << 9) + PAGE_SIZE - 1) >> PAGE_SHIFT;
-       if (nr_pages > queue_max_segments(q))
-               nr_pages = queue_max_segments(q);
+       nr_pages = min_t(unsigned,
+                    queue_max_segments(q),
+                    queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1);
+
+       return min_t(unsigned, nr_pages, BIO_MAX_PAGES);
 
-       return nr_pages;
 }
 EXPORT_SYMBOL(bio_get_nr_vecs);
 
@@ -696,7 +697,8 @@ static void bio_free_map_data(struct bio_map_data *bmd)
        kfree(bmd);
 }
 
-static struct bio_map_data *bio_alloc_map_data(int nr_segs, int iov_count,
+static struct bio_map_data *bio_alloc_map_data(int nr_segs,
+                                              unsigned int iov_count,
                                               gfp_t gfp_mask)
 {
        struct bio_map_data *bmd;
@@ -732,7 +734,7 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
        int iov_idx = 0;
        unsigned int iov_off = 0;
 
-       __bio_for_each_segment(bvec, bio, i, 0) {
+       bio_for_each_segment_all(bvec, bio, i) {
                char *bv_addr = page_address(bvec->bv_page);
                unsigned int bv_len = iovecs[i].bv_len;
 
@@ -785,12 +787,26 @@ static int __bio_copy_iov(struct bio *bio, struct bio_vec *iovecs,
 int bio_uncopy_user(struct bio *bio)
 {
        struct bio_map_data *bmd = bio->bi_private;
-       int ret = 0;
+       struct bio_vec *bvec;
+       int ret = 0, i;
 
-       if (!bio_flagged(bio, BIO_NULL_MAPPED))
-               ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
-                                    bmd->nr_sgvecs, bio_data_dir(bio) == READ,
-                                    0, bmd->is_our_pages);
+       if (!bio_flagged(bio, BIO_NULL_MAPPED)) {
+               /*
+                * if we're in a workqueue, the request is orphaned, so
+                * don't copy into a random user address space, just free
+                * and return -EINTR so user space doesn't expect any data.
+                */
+               if (current->mm)
+                       ret = __bio_copy_iov(bio, bmd->iovecs, bmd->sgvecs,
+                                            bmd->nr_sgvecs, bio_data_dir(bio) == READ,
+                                            0, bmd->is_our_pages);
+               else {
+                       ret = -EINTR;
+                       if (bmd->is_our_pages)
+                               bio_for_each_segment_all(bvec, bio, i)
+                                       __free_page(bvec->bv_page);
+               }
+       }
        bio_free_map_data(bmd);
        bio_put(bio);
        return ret;
@@ -914,7 +930,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q,
        return bio;
 cleanup:
        if (!map_data)
-               bio_for_each_segment(bvec, bio, i)
+               bio_for_each_segment_all(bvec, bio, i)
                        __free_page(bvec->bv_page);
 
        bio_put(bio);
@@ -1128,7 +1144,7 @@ static void __bio_unmap_user(struct bio *bio)
        /*
         * make sure we dirty pages we wrote to
         */
-       __bio_for_each_segment(bvec, bio, i, 0) {
+       bio_for_each_segment_all(bvec, bio, i) {
                if (bio_data_dir(bio) == READ)
                        set_page_dirty_lock(bvec->bv_page);
 
@@ -1234,7 +1250,7 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
        int i;
        char *p = bmd->sgvecs[0].iov_base;
 
-       __bio_for_each_segment(bvec, bio, i, 0) {
+       bio_for_each_segment_all(bvec, bio, i) {
                char *addr = page_address(bvec->bv_page);
                int len = bmd->iovecs[i].bv_len;
 
@@ -1274,7 +1290,7 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
        if (!reading) {
                void *p = data;
 
-               bio_for_each_segment(bvec, bio, i) {
+               bio_for_each_segment_all(bvec, bio, i) {
                        char *addr = page_address(bvec->bv_page);
 
                        memcpy(addr, p, bvec->bv_len);
@@ -1554,7 +1570,7 @@ sector_t bio_sector_offset(struct bio *bio, unsigned short index,
        if (index >= bio->bi_idx)
                index = bio->bi_vcnt - 1;
 
-       __bio_for_each_segment(bv, bio, i, 0) {
+       bio_for_each_segment_all(bv, bio, i) {
                if (i == index) {
                        if (offset > bv->bv_offset)
                                sectors += (offset - bv->bv_offset) / sector_sz;