1 files changed, 201 insertions, 188 deletions

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 44a360ca8046..02ccf766903c 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -55,13 +55,10 @@
  * blocksize.
  */
 
-struct dio {
-        /* BIO submission state */
+/* dio_state only used in the submission path */
+
+struct dio_submit {
         struct bio *bio;                /* bio under assembly */
-        struct inode *inode;
-        int rw;
-        loff_t i_size;                  /* i_size when submitted */
-        int flags;                      /* doesn't change */
         unsigned blkbits;               /* doesn't change */
         unsigned blkfactor;             /* When we're using an alignment which
                                            is finer than the filesystem's soft
@@ -81,13 +78,12 @@ struct dio {
         int boundary;                   /* prev block is at a boundary */
         int reap_counter;               /* rate limit reaping */
         get_block_t *get_block;         /* block mapping function */
-        dio_iodone_t *end_io;           /* IO completion function */
         dio_submit_t *submit_io;        /* IO submition function */
+
         loff_t logical_offset_in_bio;   /* current first logical block in bio */
         sector_t final_block_in_bio;    /* current final block in bio + 1 */
         sector_t next_block_for_io;     /* next block to be put under IO,
                                            in dio_blocks units */
-        struct buffer_head map_bh;      /* last get_block() result */
 
         /*
          * Deferred addition of a page to the dio.  These variables are
@@ -100,18 +96,6 @@ struct dio {
         sector_t cur_page_block;        /* Where it starts */
         loff_t cur_page_fs_offset;      /* Offset in file */
 
-        /* BIO completion state */
-        spinlock_t bio_lock;            /* protects BIO fields below */
-        unsigned long refcount;         /* direct_io_worker() and bios */
-        struct bio *bio_list;           /* singly linked via bi_private */
-        struct task_struct *waiter;     /* waiting task (NULL if none) */
-
-        /* AIO related stuff */
-        struct kiocb *iocb;             /* kiocb */
-        int is_async;                   /* is IO async ? */
-        int io_error;                   /* IO error in completion path */
-        ssize_t result;                 /* IO result */
-
         /*
          * Page fetching state. These variables belong to dio_refill_pages().
          */
@@ -125,6 +109,30 @@ struct dio {
          */
         unsigned head;                  /* next page to process */
         unsigned tail;                  /* last valid page + 1 */
+};
+
+/* dio_state communicated between submission path and end_io */
+struct dio {
+        int flags;                      /* doesn't change */
+        struct inode *inode;
+        int rw;
+        loff_t i_size;                  /* i_size when submitted */
+        dio_iodone_t *end_io;           /* IO completion function */
+        struct buffer_head map_bh;      /* last get_block() result */
+
+
+        /* BIO completion state */
+        spinlock_t bio_lock;            /* protects BIO fields below */
+        unsigned long refcount;         /* direct_io_worker() and bios */
+        struct bio *bio_list;           /* singly linked via bi_private */
+        struct task_struct *waiter;     /* waiting task (NULL if none) */
+
+        /* AIO related stuff */
+        struct kiocb *iocb;             /* kiocb */
+        int is_async;                   /* is IO async ? */
+        int io_error;                   /* IO error in completion path */
+        ssize_t result;                 /* IO result */
+
         int page_errors;                /* errno from get_user_pages() */
 
         /*
@@ -182,27 +190,27 @@ EXPORT_SYMBOL_GPL(inode_dio_done);
 /*
  * How many pages are in the queue?
  */
-static inline unsigned dio_pages_present(struct dio *dio)
+static inline unsigned dio_pages_present(struct dio_submit *sdio)
 {
-        return dio->tail - dio->head;
+        return sdio->tail - sdio->head;
 }
 
 /*
  * Go grab and pin some userspace pages.   Typically we'll get 64 at a time.
  */
-static int dio_refill_pages(struct dio *dio)
+static int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)
 {
         int ret;
         int nr_pages;
 
-        nr_pages = min(dio->total_pages - dio->curr_page, DIO_PAGES);
+        nr_pages = min(sdio->total_pages - sdio->curr_page, DIO_PAGES);
         ret = get_user_pages_fast(
-                dio->curr_user_address,         /* Where from? */
+                sdio->curr_user_address,                /* Where from? */
                 nr_pages,                       /* How many pages? */
                 dio->rw == READ,                /* Write to memory? */
                 &dio->pages[0]);                /* Put results here */
 
-        if (ret < 0 && dio->blocks_available && (dio->rw & WRITE)) {
+        if (ret < 0 && sdio->blocks_available && (dio->rw & WRITE)) {
                 struct page *page = ZERO_PAGE(0);
                 /*
                  * A memory fault, but the filesystem has some outstanding
@@ -213,17 +221,17 @@ static int dio_refill_pages(struct dio *dio)
                         dio->page_errors = ret;
                 page_cache_get(page);
                 dio->pages[0] = page;
-                dio->head = 0;
-                dio->tail = 1;
+                sdio->head = 0;
+                sdio->tail = 1;
                 ret = 0;
                 goto out;
         }
 
         if (ret >= 0) {
-                dio->curr_user_address += ret * PAGE_SIZE;
-                dio->curr_page += ret;
-                dio->head = 0;
-                dio->tail = ret;
+                sdio->curr_user_address += ret * PAGE_SIZE;
+                sdio->curr_page += ret;
+                sdio->head = 0;
+                sdio->tail = ret;
                 ret = 0;
         }
 out:
@@ -236,17 +244,17 @@ out:
  * decent number of pages, less frequently.  To provide nicer use of the
  * L1 cache.
  */
-static struct page *dio_get_page(struct dio *dio)
+static struct page *dio_get_page(struct dio *dio, struct dio_submit *sdio)
 {
-        if (dio_pages_present(dio) == 0) {
+        if (dio_pages_present(sdio) == 0) {
                 int ret;
 
-                ret = dio_refill_pages(dio);
+                ret = dio_refill_pages(dio, sdio);
                 if (ret)
                         return ERR_PTR(ret);
-                BUG_ON(dio_pages_present(dio) == 0);
+                BUG_ON(dio_pages_present(sdio) == 0);
         }
-        return dio->pages[dio->head++];
+        return dio->pages[sdio->head++];
 }
 
 /**
@@ -368,8 +376,9 @@ void dio_end_io(struct bio *bio, int error)
 EXPORT_SYMBOL_GPL(dio_end_io);
 
 static void
-dio_bio_alloc(struct dio *dio, struct block_device *bdev,
-                sector_t first_sector, int nr_vecs)
+dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
+              struct block_device *bdev,
+              sector_t first_sector, int nr_vecs)
 {
         struct bio *bio;
 
@@ -386,8 +395,8 @@ dio_bio_alloc(struct dio *dio, struct block_device *bdev,
         else
                 bio->bi_end_io = dio_bio_end_io;
 
-        dio->bio = bio;
-        dio->logical_offset_in_bio = dio->cur_page_fs_offset;
+        sdio->bio = bio;
+        sdio->logical_offset_in_bio = sdio->cur_page_fs_offset;
 }
 
 /*
@@ -397,9 +406,9 @@ dio_bio_alloc(struct dio *dio, struct block_device *bdev,
  *
  * bios hold a dio reference between submit_bio and ->end_io.
  */
-static void dio_bio_submit(struct dio *dio)
+static void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
 {
-        struct bio *bio = dio->bio;
+        struct bio *bio = sdio->bio;
         unsigned long flags;
 
         bio->bi_private = dio;
@@ -411,24 +420,24 @@ static void dio_bio_submit(struct dio *dio)
         if (dio->is_async && dio->rw == READ)
                 bio_set_pages_dirty(bio);
 
-        if (dio->submit_io)
-                dio->submit_io(dio->rw, bio, dio->inode,
-                               dio->logical_offset_in_bio);
+        if (sdio->submit_io)
+                sdio->submit_io(dio->rw, bio, dio->inode,
+                               sdio->logical_offset_in_bio);
         else
                 submit_bio(dio->rw, bio);
 
-        dio->bio = NULL;
-        dio->boundary = 0;
-        dio->logical_offset_in_bio = 0;
+        sdio->bio = NULL;
+        sdio->boundary = 0;
+        sdio->logical_offset_in_bio = 0;
 }
 
 /*
  * Release any resources in case of a failure
  */
-static void dio_cleanup(struct dio *dio)
+static void dio_cleanup(struct dio *dio, struct dio_submit *sdio)
 {
-        while (dio_pages_present(dio))
-                page_cache_release(dio_get_page(dio));
+        while (dio_pages_present(sdio))
+                page_cache_release(dio_get_page(dio, sdio));
 }
 
 /*
@@ -518,11 +527,11 @@ static void dio_await_completion(struct dio *dio)
  *
  * This also helps to limit the peak amount of pinned userspace memory.
  */
-static int dio_bio_reap(struct dio *dio)
+static int dio_bio_reap(struct dio *dio, struct dio_submit *sdio)
 {
         int ret = 0;
 
-        if (dio->reap_counter++ >= 64) {
+        if (sdio->reap_counter++ >= 64) {
                 while (dio->bio_list) {
                         unsigned long flags;
                         struct bio *bio;
@@ -536,14 +545,14 @@ static int dio_bio_reap(struct dio *dio)
                         if (ret == 0)
                                 ret = ret2;
                 }
-                dio->reap_counter = 0;
+                sdio->reap_counter = 0;
         }
         return ret;
 }
 
 /*
  * Call into the fs to map some more disk blocks.  We record the current number
- * of available blocks at dio->blocks_available.  These are in units of the
+ * of available blocks at sdio->blocks_available.  These are in units of the
  * fs blocksize, (1 << inode->i_blkbits).
  *
  * The fs is allowed to map lots of blocks at once.  If it wants to do that,
@@ -564,7 +573,7 @@ static int dio_bio_reap(struct dio *dio)
  * buffer_mapped().  However the direct-io code will only process holes one
  * block at a time - it will repeatedly call get_block() as it walks the hole.
  */
-static int get_more_blocks(struct dio *dio)
+static int get_more_blocks(struct dio *dio, struct dio_submit *sdio)
 {
         int ret;
         struct buffer_head *map_bh = &dio->map_bh;
@@ -580,11 +589,11 @@ static int get_more_blocks(struct dio *dio)
          */
         ret = dio->page_errors;
         if (ret == 0) {
-                BUG_ON(dio->block_in_file >= dio->final_block_in_request);
-                fs_startblk = dio->block_in_file >> dio->blkfactor;
-                dio_count = dio->final_block_in_request - dio->block_in_file;
-                fs_count = dio_count >> dio->blkfactor;
-                blkmask = (1 << dio->blkfactor) - 1;
+                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++;
 
@@ -604,12 +613,12 @@ static int get_more_blocks(struct dio *dio)
                  */
                 create = dio->rw & WRITE;
                 if (dio->flags & DIO_SKIP_HOLES) {
-                        if (dio->block_in_file < (i_size_read(dio->inode) >>
-                                                        dio->blkbits))
+                        if (sdio->block_in_file < (i_size_read(dio->inode) >>
+                                                        sdio->blkbits))
                                 create = 0;
                 }
 
-                ret = (*dio->get_block)(dio->inode, fs_startblk,
+                ret = (*sdio->get_block)(dio->inode, fs_startblk,
                                                 map_bh, create);
         }
         return ret;
@@ -618,20 +627,21 @@ static int get_more_blocks(struct dio *dio)
 /*
  * There is no bio.  Make one now.
  */
-static int dio_new_bio(struct dio *dio, sector_t start_sector)
+static int dio_new_bio(struct dio *dio, struct dio_submit *sdio,
+                       sector_t start_sector)
 {
         sector_t sector;
         int ret, nr_pages;
 
-        ret = dio_bio_reap(dio);
+        ret = dio_bio_reap(dio, sdio);
         if (ret)
                 goto out;
-        sector = start_sector << (dio->blkbits - 9);
-        nr_pages = min(dio->pages_in_io, bio_get_nr_vecs(dio->map_bh.b_bdev));
+        sector = start_sector << (sdio->blkbits - 9);
+        nr_pages = min(sdio->pages_in_io, bio_get_nr_vecs(dio->map_bh.b_bdev));
         nr_pages = min(nr_pages, BIO_MAX_PAGES);
         BUG_ON(nr_pages <= 0);
-        dio_bio_alloc(dio, dio->map_bh.b_bdev, sector, nr_pages);
-        dio->boundary = 0;
+        dio_bio_alloc(dio, sdio, dio->map_bh.b_bdev, sector, nr_pages);
+        sdio->boundary = 0;
 out:
         return ret;
 }
@@ -643,21 +653,21 @@ out:
  *
  * Return zero on success.  Non-zero means the caller needs to start a new BIO.
  */
-static int dio_bio_add_page(struct dio *dio)
+static int dio_bio_add_page(struct dio_submit *sdio)
 {
         int ret;
 
-        ret = bio_add_page(dio->bio, dio->cur_page,
-                        dio->cur_page_len, dio->cur_page_offset);
-        if (ret == dio->cur_page_len) {
+        ret = bio_add_page(sdio->bio, sdio->cur_page,
+                        sdio->cur_page_len, sdio->cur_page_offset);
+        if (ret == sdio->cur_page_len) {
                 /*
                  * Decrement count only, if we are done with this page
                  */
-                if ((dio->cur_page_len + dio->cur_page_offset) == PAGE_SIZE)
-                        dio->pages_in_io--;
-                page_cache_get(dio->cur_page);
-                dio->final_block_in_bio = dio->cur_page_block +
-                        (dio->cur_page_len >> dio->blkbits);
+                if ((sdio->cur_page_len + sdio->cur_page_offset) == PAGE_SIZE)
+                        sdio->pages_in_io--;
+                page_cache_get(sdio->cur_page);
+                sdio->final_block_in_bio = sdio->cur_page_block +
+                        (sdio->cur_page_len >> sdio->blkbits);
                 ret = 0;
         } else {
                 ret = 1;
@@ -675,14 +685,14 @@ static int dio_bio_add_page(struct dio *dio)
  * The caller of this function is responsible for removing cur_page from the
  * dio, and for dropping the refcount which came from that presence.
  */
-static int dio_send_cur_page(struct dio *dio)
+static int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio)
 {
         int ret = 0;
 
-        if (dio->bio) {
-                loff_t cur_offset = dio->cur_page_fs_offset;
-                loff_t bio_next_offset = dio->logical_offset_in_bio +
-                        dio->bio->bi_size;
+        if (sdio->bio) {
+                loff_t cur_offset = sdio->cur_page_fs_offset;
+                loff_t bio_next_offset = sdio->logical_offset_in_bio +
+                        sdio->bio->bi_size;
 
                 /*
                  * See whether this new request is contiguous with the old.
@@ -698,28 +708,28 @@ static int dio_send_cur_page(struct dio *dio)
                  * be the next logical offset in the bio, submit the bio we
                  * have.
                  */
-                if (dio->final_block_in_bio != dio->cur_page_block ||
+                if (sdio->final_block_in_bio != sdio->cur_page_block ||
                     cur_offset != bio_next_offset)
-                        dio_bio_submit(dio);
+                        dio_bio_submit(dio, sdio);
                 /*
                  * Submit now if the underlying fs is about to perform a
                  * metadata read
                  */
-                else if (dio->boundary)
-                        dio_bio_submit(dio);
+                else if (sdio->boundary)
+                        dio_bio_submit(dio, sdio);
         }
 
-        if (dio->bio == NULL) {
-                ret = dio_new_bio(dio, dio->cur_page_block);
+        if (sdio->bio == NULL) {
+                ret = dio_new_bio(dio, sdio, sdio->cur_page_block);
                 if (ret)
                         goto out;
         }
 
-        if (dio_bio_add_page(dio) != 0) {
-                dio_bio_submit(dio);
-                ret = dio_new_bio(dio, dio->cur_page_block);
+        if (dio_bio_add_page(sdio) != 0) {
+                dio_bio_submit(dio, sdio);
+                ret = dio_new_bio(dio, sdio, sdio->cur_page_block);
                 if (ret == 0) {
-                        ret = dio_bio_add_page(dio);
+                        ret = dio_bio_add_page(sdio);
                         BUG_ON(ret != 0);
                 }
         }
@@ -745,7 +755,7 @@ out:
  * page to the dio instead.
  */
 static int
-submit_page_section(struct dio *dio, struct page *page,
+submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,
                 unsigned offset, unsigned len, sector_t blocknr)
 {
         int ret = 0;
@@ -760,20 +770,20 @@ submit_page_section(struct dio *dio, struct page *page,
         /*
          * Can we just grow the current page's presence in the dio?
          */
-        if (    (dio->cur_page == page) &&
-                (dio->cur_page_offset + dio->cur_page_len == offset) &&
-                (dio->cur_page_block +
-                        (dio->cur_page_len >> dio->blkbits) == blocknr)) {
-                dio->cur_page_len += len;
+        if (sdio->cur_page == page &&
+            sdio->cur_page_offset + sdio->cur_page_len == offset &&
+            sdio->cur_page_block +
+            (sdio->cur_page_len >> sdio->blkbits) == blocknr) {
+                sdio->cur_page_len += len;
 
                 /*
-                 * If dio->boundary then we want to schedule the IO now to
+                 * If sdio->boundary then we want to schedule the IO now to
                  * avoid metadata seeks.
                  */
-                if (dio->boundary) {
-                        ret = dio_send_cur_page(dio);
-                        page_cache_release(dio->cur_page);
-                        dio->cur_page = NULL;
+                if (sdio->boundary) {
+                        ret = dio_send_cur_page(dio, sdio);
+                        page_cache_release(sdio->cur_page);
+                        sdio->cur_page = NULL;
                 }
                 goto out;
         }
@@ -781,20 +791,20 @@ submit_page_section(struct dio *dio, struct page *page,
         /*
          * If there's a deferred page already there then send it.
          */
-        if (dio->cur_page) {
-                ret = dio_send_cur_page(dio);
-                page_cache_release(dio->cur_page);
-                dio->cur_page = NULL;
+        if (sdio->cur_page) {
+                ret = dio_send_cur_page(dio, sdio);
+                page_cache_release(sdio->cur_page);
+                sdio->cur_page = NULL;
                 if (ret)
                         goto out;
         }
 
         page_cache_get(page);           /* It is in dio */
-        dio->cur_page = page;
-        dio->cur_page_offset = offset;
-        dio->cur_page_len = len;
-        dio->cur_page_block = blocknr;
-        dio->cur_page_fs_offset = dio->block_in_file << dio->blkbits;
+        sdio->cur_page = page;
+        sdio->cur_page_offset = offset;
+        sdio->cur_page_len = len;
+        sdio->cur_page_block = blocknr;
+        sdio->cur_page_fs_offset = sdio->block_in_file << sdio->blkbits;
 out:
         return ret;
 }
@@ -826,19 +836,19 @@ static void clean_blockdev_aliases(struct dio *dio)
  * `end' is zero if we're doing the start of the IO, 1 at the end of the
  * IO.
  */
-static void dio_zero_block(struct dio *dio, int end)
+static void dio_zero_block(struct dio *dio, struct dio_submit *sdio, int end)
 {
         unsigned dio_blocks_per_fs_block;
         unsigned this_chunk_blocks;     /* In dio_blocks */
         unsigned this_chunk_bytes;
         struct page *page;
 
-        dio->start_zero_done = 1;
-        if (!dio->blkfactor || !buffer_new(&dio->map_bh))
+        sdio->start_zero_done = 1;
+        if (!sdio->blkfactor || !buffer_new(&dio->map_bh))
                 return;
 
-        dio_blocks_per_fs_block = 1 << dio->blkfactor;
-        this_chunk_blocks = dio->block_in_file & (dio_blocks_per_fs_block - 1);
+        dio_blocks_per_fs_block = 1 << sdio->blkfactor;
+        this_chunk_blocks = sdio->block_in_file & (dio_blocks_per_fs_block - 1);
 
         if (!this_chunk_blocks)
                 return;
@@ -850,14 +860,14 @@ static void dio_zero_block(struct dio *dio, int end)
         if (end) 
                 this_chunk_blocks = dio_blocks_per_fs_block - this_chunk_blocks;
 
-        this_chunk_bytes = this_chunk_blocks << dio->blkbits;
+        this_chunk_bytes = this_chunk_blocks << sdio->blkbits;
 
         page = ZERO_PAGE(0);
-        if (submit_page_section(dio, page, 0, this_chunk_bytes, 
-                                dio->next_block_for_io))
+        if (submit_page_section(dio, sdio, page, 0, this_chunk_bytes,
+                                sdio->next_block_for_io))
                 return;
 
-        dio->next_block_for_io += this_chunk_blocks;
+        sdio->next_block_for_io += this_chunk_blocks;
 }
 
 /*
@@ -876,9 +886,9 @@ static void dio_zero_block(struct dio *dio, int end)
  * it should set b_size to PAGE_SIZE or more inside get_block().  This gives
  * fine alignment but still allows this function to work in PAGE_SIZE units.
  */
-static int do_direct_IO(struct dio *dio)
+static int do_direct_IO(struct dio *dio, struct dio_submit *sdio)
 {
-        const unsigned blkbits = dio->blkbits;
+        const unsigned blkbits = sdio->blkbits;
         const unsigned blocks_per_page = PAGE_SIZE >> blkbits;
         struct page *page;
         unsigned block_in_page;
@@ -886,10 +896,10 @@ static int do_direct_IO(struct dio *dio)
         int ret = 0;
 
         /* The I/O can start at any block offset within the first page */
-        block_in_page = dio->first_block_in_page;
+        block_in_page = sdio->first_block_in_page;
 
-        while (dio->block_in_file < dio->final_block_in_request) {
-                page = dio_get_page(dio);
+        while (sdio->block_in_file < sdio->final_block_in_request) {
+                page = dio_get_page(dio, sdio);
                 if (IS_ERR(page)) {
                         ret = PTR_ERR(page);
                         goto out;
@@ -901,14 +911,14 @@ static int do_direct_IO(struct dio *dio)
                         unsigned this_chunk_blocks;     /* # of blocks */
                         unsigned u;
 
-                        if (dio->blocks_available == 0) {
+                        if (sdio->blocks_available == 0) {
                                 /*
                                  * Need to go and map some more disk
                                  */
                                 unsigned long blkmask;
                                 unsigned long dio_remainder;
 
-                                ret = get_more_blocks(dio);
+                                ret = get_more_blocks(dio, sdio);
                                 if (ret) {
                                         page_cache_release(page);
                                         goto out;
@@ -916,18 +926,18 @@ static int do_direct_IO(struct dio *dio)
                                 if (!buffer_mapped(map_bh))
                                         goto do_holes;
 
-                                dio->blocks_available =
-                                                map_bh->b_size >> dio->blkbits;
-                                dio->next_block_for_io =
-                                        map_bh->b_blocknr << dio->blkfactor;
+                                sdio->blocks_available =
+                                                map_bh->b_size >> sdio->blkbits;
+                                sdio->next_block_for_io =
+                                        map_bh->b_blocknr << sdio->blkfactor;
                                 if (buffer_new(map_bh))
                                         clean_blockdev_aliases(dio);
 
-                                if (!dio->blkfactor)
+                                if (!sdio->blkfactor)
                                         goto do_holes;
 
-                                blkmask = (1 << dio->blkfactor) - 1;
-                                dio_remainder = (dio->block_in_file & blkmask);
+                                blkmask = (1 << sdio->blkfactor) - 1;
+                                dio_remainder = (sdio->block_in_file & blkmask);
 
                                 /*
                                  * If we are at the start of IO and that IO
@@ -941,8 +951,8 @@ static int do_direct_IO(struct dio *dio)
                                  * on-disk
                                  */
                                 if (!buffer_new(map_bh))
-                                        dio->next_block_for_io += dio_remainder;
-                                dio->blocks_available -= dio_remainder;
+                                        sdio->next_block_for_io += dio_remainder;
+                                sdio->blocks_available -= dio_remainder;
                         }
 do_holes:
                         /* Handle holes */
@@ -961,7 +971,7 @@ do_holes:
                                  */
                                 i_size_aligned = ALIGN(i_size_read(dio->inode),
                                                         1 << blkbits);
-                                if (dio->block_in_file >=
+                                if (sdio->block_in_file >=
                                                 i_size_aligned >> blkbits) {
                                         /* We hit eof */
                                         page_cache_release(page);
@@ -969,7 +979,7 @@ do_holes:
                                 }
                                 zero_user(page, block_in_page << blkbits,
                                                 1 << blkbits);
-                                dio->block_in_file++;
+                                sdio->block_in_file++;
                                 block_in_page++;
                                 goto next_block;
                         }
@@ -979,38 +989,40 @@ do_holes:
                          * is finer than the underlying fs, go check to see if
                          * we must zero out the start of this block.
                          */
-                        if (unlikely(dio->blkfactor && !dio->start_zero_done))
-                                dio_zero_block(dio, 0);
+                        if (unlikely(sdio->blkfactor && !sdio->start_zero_done))
+                                dio_zero_block(dio, sdio, 0);
 
                         /*
                          * Work out, in this_chunk_blocks, how much disk we
                          * can add to this page
                          */
-                        this_chunk_blocks = dio->blocks_available;
+                        this_chunk_blocks = sdio->blocks_available;
                         u = (PAGE_SIZE - offset_in_page) >> blkbits;
                         if (this_chunk_blocks > u)
                                 this_chunk_blocks = u;
-                        u = dio->final_block_in_request - dio->block_in_file;
+                        u = sdio->final_block_in_request - sdio->block_in_file;
                         if (this_chunk_blocks > u)
                                 this_chunk_blocks = u;
                         this_chunk_bytes = this_chunk_blocks << blkbits;
                         BUG_ON(this_chunk_bytes == 0);
 
-                        dio->boundary = buffer_boundary(map_bh);
-                        ret = submit_page_section(dio, page, offset_in_page,
-                                this_chunk_bytes, dio->next_block_for_io);
+                        sdio->boundary = buffer_boundary(map_bh);
+                        ret = submit_page_section(dio, sdio, page,
+                                                  offset_in_page,
+                                                  this_chunk_bytes,
+                                                  sdio->next_block_for_io);
                         if (ret) {
                                 page_cache_release(page);
                                 goto out;
                         }
-                        dio->next_block_for_io += this_chunk_blocks;
+                        sdio->next_block_for_io += this_chunk_blocks;
 
-                        dio->block_in_file += this_chunk_blocks;
+                        sdio->block_in_file += this_chunk_blocks;
                         block_in_page += this_chunk_blocks;
-                        dio->blocks_available -= this_chunk_blocks;
+                        sdio->blocks_available -= this_chunk_blocks;
 next_block:
-                        BUG_ON(dio->block_in_file > dio->final_block_in_request);
-                        if (dio->block_in_file == dio->final_block_in_request)
+                        BUG_ON(sdio->block_in_file > sdio->final_block_in_request);
+                        if (sdio->block_in_file == sdio->final_block_in_request)
                                 break;
                 }
 
@@ -1026,7 +1038,7 @@ static ssize_t
 direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode, 
         const struct iovec *iov, loff_t offset, unsigned long nr_segs, 
         unsigned blkbits, get_block_t get_block, dio_iodone_t end_io,
-        dio_submit_t submit_io, struct dio *dio)
+        dio_submit_t submit_io, struct dio *dio, struct dio_submit *sdio)
 {
         unsigned long user_addr; 
         unsigned long flags;
@@ -1037,15 +1049,15 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
 
         dio->inode = inode;
         dio->rw = rw;
-        dio->blkbits = blkbits;
-        dio->blkfactor = inode->i_blkbits - blkbits;
-        dio->block_in_file = offset >> blkbits;
+        sdio->blkbits = blkbits;
+        sdio->blkfactor = inode->i_blkbits - blkbits;
+        sdio->block_in_file = offset >> blkbits;
 
-        dio->get_block = get_block;
+        sdio->get_block = get_block;
         dio->end_io = end_io;
-        dio->submit_io = submit_io;
-        dio->final_block_in_bio = -1;
-        dio->next_block_for_io = -1;
+        sdio->submit_io = submit_io;
+        sdio->final_block_in_bio = -1;
+        sdio->next_block_for_io = -1;
 
         dio->iocb = iocb;
         dio->i_size = i_size_read(inode);
@@ -1057,45 +1069,45 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
          * In case of non-aligned buffers, we may need 2 more
          * pages since we need to zero out first and last block.
          */
-        if (unlikely(dio->blkfactor))
-                dio->pages_in_io = 2;
+        if (unlikely(sdio->blkfactor))
+                sdio->pages_in_io = 2;
 
         for (seg = 0; seg < nr_segs; seg++) {
                 user_addr = (unsigned long)iov[seg].iov_base;
-                dio->pages_in_io +=
+                sdio->pages_in_io +=
                         ((user_addr+iov[seg].iov_len +PAGE_SIZE-1)/PAGE_SIZE
                                 - user_addr/PAGE_SIZE);
         }
 
         for (seg = 0; seg < nr_segs; seg++) {
                 user_addr = (unsigned long)iov[seg].iov_base;
-                dio->size += bytes = iov[seg].iov_len;
+                sdio->size += bytes = iov[seg].iov_len;
 
                 /* Index into the first page of the first block */
-                dio->first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
-                dio->final_block_in_request = dio->block_in_file +
+                sdio->first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
+                sdio->final_block_in_request = sdio->block_in_file +
                                                 (bytes >> blkbits);
                 /* Page fetching state */
-                dio->head = 0;
-                dio->tail = 0;
-                dio->curr_page = 0;
+                sdio->head = 0;
+                sdio->tail = 0;
+                sdio->curr_page = 0;
 
-                dio->total_pages = 0;
+                sdio->total_pages = 0;
                 if (user_addr & (PAGE_SIZE-1)) {
-                        dio->total_pages++;
+                        sdio->total_pages++;
                         bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1));
                 }
-                dio->total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
-                dio->curr_user_address = user_addr;
+                sdio->total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
+                sdio->curr_user_address = user_addr;
         
-                ret = do_direct_IO(dio);
+                ret = do_direct_IO(dio, sdio);
 
                 dio->result += iov[seg].iov_len -
-                        ((dio->final_block_in_request - dio->block_in_file) <<
+                        ((sdio->final_block_in_request - sdio->block_in_file) <<
                                         blkbits);
 
                 if (ret) {
-                        dio_cleanup(dio);
+                        dio_cleanup(dio, sdio);
                         break;
                 }
         } /* end iovec loop */
@@ -1111,23 +1123,23 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
          * There may be some unwritten disk at the end of a part-written
          * fs-block-sized block.  Go zero that now.
          */
-        dio_zero_block(dio, 1);
+        dio_zero_block(dio, sdio, 1);
 
-        if (dio->cur_page) {
-                ret2 = dio_send_cur_page(dio);
+        if (sdio->cur_page) {
+                ret2 = dio_send_cur_page(dio, sdio);
                 if (ret == 0)
                         ret = ret2;
-                page_cache_release(dio->cur_page);
-                dio->cur_page = NULL;
+                page_cache_release(sdio->cur_page);
+                sdio->cur_page = NULL;
         }
-        if (dio->bio)
-                dio_bio_submit(dio);
+        if (sdio->bio)
+                dio_bio_submit(dio, sdio);
 
         /*
          * It is possible that, we return short IO due to end of file.
          * In that case, we need to release all the pages we got hold on.
          */
-        dio_cleanup(dio);
+        dio_cleanup(dio, sdio);
 
         /*
          * All block lookups have been performed. For READ requests
@@ -1146,7 +1158,7 @@ direct_io_worker(int rw, struct kiocb *iocb, struct inode *inode,
          */
         BUG_ON(ret == -EIOCBQUEUED);
         if (dio->is_async && ret == 0 && dio->result &&
-            ((rw & READ) || (dio->result == dio->size)))
+            ((rw & READ) || (dio->result == sdio->size)))
                 ret = -EIOCBQUEUED;
 
         if (ret != -EIOCBQUEUED)
@@ -1211,6 +1223,7 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
         ssize_t retval = -EINVAL;
         loff_t end = offset;
         struct dio *dio;
+        struct dio_submit sdio = { 0, };
 
         if (rw & WRITE)
                 rw = WRITE_ODIRECT;
@@ -1290,7 +1303,7 @@ __blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
 
         retval = direct_io_worker(rw, iocb, inode, iov, offset,
                                 nr_segs, blkbits, get_block, end_io,
-                                submit_io, dio);
+                                  submit_io, dio, &sdio);
 
 out:
         return retval;