sector_t block_in_file; /* Current offset into the underlying
file in dio_block units. */
unsigned blocks_available; /* At block_in_file. changes */
+ int reap_counter; /* rate limit reaping */
sector_t final_block_in_request;/* doesn't change */
unsigned first_block_in_page; /* doesn't change, Used only once */
int boundary; /* prev block is at a boundary */
- int reap_counter; /* rate limit reaping */
get_block_t *get_block; /* block mapping function */
dio_submit_t *submit_io; /* IO submition function */
/* dio_state communicated between submission path and end_io */
struct dio {
int flags; /* doesn't change */
- struct inode *inode;
int rw;
+ struct inode *inode;
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 */
+ void *private; /* copy from map_bh.b_private */
/* BIO completion state */
spinlock_t bio_lock; /* protects BIO fields below */
+ int page_errors; /* errno from get_user_pages() */
+ int is_async; /* is IO async ? */
+ int io_error; /* IO error in completion path */
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() */
-
/*
* pages[] (and any fields placed after it) are not zeroed out at
* allocation time. Don't add new fields after pages[] unless you
* wish that they not be zeroed.
*/
struct page *pages[DIO_PAGES]; /* page buffer */
-};
+} ____cacheline_aligned_in_smp;
+
+static struct kmem_cache *dio_cache __read_mostly;
static void __inode_dio_wait(struct inode *inode)
{
/*
* Go grab and pin some userspace pages. Typically we'll get 64 at a time.
*/
-static int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)
+static inline int dio_refill_pages(struct dio *dio, struct dio_submit *sdio)
{
int ret;
int nr_pages;
* decent number of pages, less frequently. To provide nicer use of the
* L1 cache.
*/
-static struct page *dio_get_page(struct dio *dio, struct dio_submit *sdio)
+static inline struct page *dio_get_page(struct dio *dio,
+ struct dio_submit *sdio)
{
if (dio_pages_present(sdio) == 0) {
int ret;
if (dio->end_io && dio->result) {
dio->end_io(dio->iocb, offset, transferred,
- dio->map_bh.b_private, ret, is_async);
+ dio->private, ret, is_async);
} else {
+ inode_dio_done(dio->inode);
if (is_async)
aio_complete(dio->iocb, ret, 0);
- inode_dio_done(dio->inode);
}
return ret;
if (remaining == 0) {
dio_complete(dio, dio->iocb->ki_pos, 0, true);
- kfree(dio);
+ kmem_cache_free(dio_cache, dio);
}
}
}
EXPORT_SYMBOL_GPL(dio_end_io);
-static void
+static inline void
dio_bio_alloc(struct dio *dio, struct dio_submit *sdio,
struct block_device *bdev,
sector_t first_sector, int nr_vecs)
*
* bios hold a dio reference between submit_bio and ->end_io.
*/
-static void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
+static inline void dio_bio_submit(struct dio *dio, struct dio_submit *sdio)
{
struct bio *bio = sdio->bio;
unsigned long flags;
/*
* Release any resources in case of a failure
*/
-static void dio_cleanup(struct dio *dio, struct dio_submit *sdio)
+static inline void dio_cleanup(struct dio *dio, struct dio_submit *sdio)
{
while (dio_pages_present(sdio))
page_cache_release(dio_get_page(dio, sdio));
*
* This also helps to limit the peak amount of pinned userspace memory.
*/
-static int dio_bio_reap(struct dio *dio, struct dio_submit *sdio)
+static inline int dio_bio_reap(struct dio *dio, struct dio_submit *sdio)
{
int ret = 0;
* 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, struct dio_submit *sdio)
+static int get_more_blocks(struct dio *dio, struct dio_submit *sdio,
+ struct buffer_head *map_bh)
{
int ret;
- struct buffer_head *map_bh = &dio->map_bh;
sector_t fs_startblk; /* 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 */
ret = (*sdio->get_block)(dio->inode, fs_startblk,
map_bh, create);
+
+ /* Store for completion */
+ dio->private = map_bh->b_private;
}
return ret;
}
/*
* There is no bio. Make one now.
*/
-static int dio_new_bio(struct dio *dio, struct dio_submit *sdio,
- sector_t start_sector)
+static inline int dio_new_bio(struct dio *dio, struct dio_submit *sdio,
+ sector_t start_sector, struct buffer_head *map_bh)
{
sector_t sector;
int ret, nr_pages;
if (ret)
goto out;
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(sdio->pages_in_io, bio_get_nr_vecs(map_bh->b_bdev));
nr_pages = min(nr_pages, BIO_MAX_PAGES);
BUG_ON(nr_pages <= 0);
- dio_bio_alloc(dio, sdio, dio->map_bh.b_bdev, sector, nr_pages);
+ dio_bio_alloc(dio, sdio, map_bh->b_bdev, sector, nr_pages);
sdio->boundary = 0;
out:
return ret;
*
* Return zero on success. Non-zero means the caller needs to start a new BIO.
*/
-static int dio_bio_add_page(struct dio_submit *sdio)
+static inline int dio_bio_add_page(struct dio_submit *sdio)
{
int ret;
* 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, struct dio_submit *sdio)
+static inline int dio_send_cur_page(struct dio *dio, struct dio_submit *sdio,
+ struct buffer_head *map_bh)
{
int ret = 0;
}
if (sdio->bio == NULL) {
- ret = dio_new_bio(dio, sdio, sdio->cur_page_block);
+ ret = dio_new_bio(dio, sdio, sdio->cur_page_block, map_bh);
if (ret)
goto out;
}
if (dio_bio_add_page(sdio) != 0) {
dio_bio_submit(dio, sdio);
- ret = dio_new_bio(dio, sdio, sdio->cur_page_block);
+ ret = dio_new_bio(dio, sdio, sdio->cur_page_block, map_bh);
if (ret == 0) {
ret = dio_bio_add_page(sdio);
BUG_ON(ret != 0);
* If that doesn't work out then we put the old page into the bio and add this
* page to the dio instead.
*/
-static int
+static inline int
submit_page_section(struct dio *dio, struct dio_submit *sdio, struct page *page,
- unsigned offset, unsigned len, sector_t blocknr)
+ unsigned offset, unsigned len, sector_t blocknr,
+ struct buffer_head *map_bh)
{
int ret = 0;
* avoid metadata seeks.
*/
if (sdio->boundary) {
- ret = dio_send_cur_page(dio, sdio);
+ ret = dio_send_cur_page(dio, sdio, map_bh);
page_cache_release(sdio->cur_page);
sdio->cur_page = NULL;
}
* If there's a deferred page already there then send it.
*/
if (sdio->cur_page) {
- ret = dio_send_cur_page(dio, sdio);
+ ret = dio_send_cur_page(dio, sdio, map_bh);
page_cache_release(sdio->cur_page);
sdio->cur_page = NULL;
if (ret)
* file blocks. Only called for S_ISREG files - blockdevs do not set
* buffer_new
*/
-static void clean_blockdev_aliases(struct dio *dio)
+static void clean_blockdev_aliases(struct dio *dio, struct buffer_head *map_bh)
{
unsigned i;
unsigned nblocks;
- nblocks = dio->map_bh.b_size >> dio->inode->i_blkbits;
+ nblocks = map_bh->b_size >> dio->inode->i_blkbits;
for (i = 0; i < nblocks; i++) {
- unmap_underlying_metadata(dio->map_bh.b_bdev,
- dio->map_bh.b_blocknr + i);
+ unmap_underlying_metadata(map_bh->b_bdev,
+ map_bh->b_blocknr + i);
}
}
* `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, struct dio_submit *sdio, int end)
+static inline void dio_zero_block(struct dio *dio, struct dio_submit *sdio,
+ int end, struct buffer_head *map_bh)
{
unsigned dio_blocks_per_fs_block;
unsigned this_chunk_blocks; /* In dio_blocks */
struct page *page;
sdio->start_zero_done = 1;
- if (!sdio->blkfactor || !buffer_new(&dio->map_bh))
+ if (!sdio->blkfactor || !buffer_new(map_bh))
return;
dio_blocks_per_fs_block = 1 << sdio->blkfactor;
page = ZERO_PAGE(0);
if (submit_page_section(dio, sdio, page, 0, this_chunk_bytes,
- sdio->next_block_for_io))
+ sdio->next_block_for_io, map_bh))
return;
sdio->next_block_for_io += this_chunk_blocks;
* 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, struct dio_submit *sdio)
+static int do_direct_IO(struct dio *dio, struct dio_submit *sdio,
+ struct buffer_head *map_bh)
{
const unsigned blkbits = sdio->blkbits;
const unsigned blocks_per_page = PAGE_SIZE >> blkbits;
struct page *page;
unsigned block_in_page;
- struct buffer_head *map_bh = &dio->map_bh;
int ret = 0;
/* The I/O can start at any block offset within the first page */
unsigned long blkmask;
unsigned long dio_remainder;
- ret = get_more_blocks(dio, sdio);
+ ret = get_more_blocks(dio, sdio, map_bh);
if (ret) {
page_cache_release(page);
goto out;
sdio->next_block_for_io =
map_bh->b_blocknr << sdio->blkfactor;
if (buffer_new(map_bh))
- clean_blockdev_aliases(dio);
+ clean_blockdev_aliases(dio, map_bh);
if (!sdio->blkfactor)
goto do_holes;
* we must zero out the start of this block.
*/
if (unlikely(sdio->blkfactor && !sdio->start_zero_done))
- dio_zero_block(dio, sdio, 0);
+ dio_zero_block(dio, sdio, 0, map_bh);
/*
* Work out, in this_chunk_blocks, how much disk we
ret = submit_page_section(dio, sdio, page,
offset_in_page,
this_chunk_bytes,
- sdio->next_block_for_io);
+ sdio->next_block_for_io,
+ map_bh);
if (ret) {
page_cache_release(page);
goto out;
return ret;
}
-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, struct dio_submit *sdio)
+static inline int drop_refcount(struct dio *dio)
{
- unsigned long user_addr;
+ int ret2;
unsigned long flags;
- int seg;
- ssize_t ret = 0;
- ssize_t ret2;
- size_t bytes;
-
- dio->inode = inode;
- dio->rw = rw;
- sdio->blkbits = blkbits;
- sdio->blkfactor = inode->i_blkbits - blkbits;
- sdio->block_in_file = offset >> blkbits;
-
- sdio->get_block = get_block;
- dio->end_io = end_io;
- 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);
-
- spin_lock_init(&dio->bio_lock);
- dio->refcount = 1;
-
- /*
- * In case of non-aligned buffers, we may need 2 more
- * pages since we need to zero out first and last block.
- */
- if (unlikely(sdio->blkfactor))
- sdio->pages_in_io = 2;
-
- for (seg = 0; seg < nr_segs; seg++) {
- user_addr = (unsigned long)iov[seg].iov_base;
- 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;
- sdio->size += bytes = iov[seg].iov_len;
-
- /* Index into the first page of the first block */
- sdio->first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
- sdio->final_block_in_request = sdio->block_in_file +
- (bytes >> blkbits);
- /* Page fetching state */
- sdio->head = 0;
- sdio->tail = 0;
- sdio->curr_page = 0;
-
- sdio->total_pages = 0;
- if (user_addr & (PAGE_SIZE-1)) {
- sdio->total_pages++;
- bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1));
- }
- sdio->total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
- sdio->curr_user_address = user_addr;
-
- ret = do_direct_IO(dio, sdio);
-
- dio->result += iov[seg].iov_len -
- ((sdio->final_block_in_request - sdio->block_in_file) <<
- blkbits);
-
- if (ret) {
- dio_cleanup(dio, sdio);
- break;
- }
- } /* end iovec loop */
-
- if (ret == -ENOTBLK) {
- /*
- * The remaining part of the request will be
- * be handled by buffered I/O when we return
- */
- ret = 0;
- }
- /*
- * 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, sdio, 1);
-
- if (sdio->cur_page) {
- ret2 = dio_send_cur_page(dio, sdio);
- if (ret == 0)
- ret = ret2;
- page_cache_release(sdio->cur_page);
- sdio->cur_page = NULL;
- }
- 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, sdio);
-
- /*
- * All block lookups have been performed. For READ requests
- * we can let i_mutex go now that its achieved its purpose
- * of protecting us from looking up uninitialized blocks.
- */
- if (rw == READ && (dio->flags & DIO_LOCKING))
- mutex_unlock(&dio->inode->i_mutex);
-
- /*
- * The only time we want to leave bios in flight is when a successful
- * partial aio read or full aio write have been setup. In that case
- * bio completion will call aio_complete. The only time it's safe to
- * call aio_complete is when we return -EIOCBQUEUED, so we key on that.
- * This had *better* be the only place that raises -EIOCBQUEUED.
- */
- BUG_ON(ret == -EIOCBQUEUED);
- if (dio->is_async && ret == 0 && dio->result &&
- ((rw & READ) || (dio->result == sdio->size)))
- ret = -EIOCBQUEUED;
-
- if (ret != -EIOCBQUEUED)
- dio_await_completion(dio);
/*
* Sync will always be dropping the final ref and completing the
spin_lock_irqsave(&dio->bio_lock, flags);
ret2 = --dio->refcount;
spin_unlock_irqrestore(&dio->bio_lock, flags);
-
- if (ret2 == 0) {
- ret = dio_complete(dio, offset, ret, false);
- kfree(dio);
- } else
- BUG_ON(ret != -EIOCBQUEUED);
-
- return ret;
+ return ret2;
}
/*
* expected that filesystem provide exclusion between new direct I/O
* and truncates. For DIO_LOCKING filesystems this is done by i_mutex,
* but other filesystems need to take care of this on their own.
+ *
+ * NOTE: if you pass "sdio" to anything by pointer make sure that function
+ * is always inlined. Otherwise gcc is unable to split the structure into
+ * individual fields and will generate much worse code. This is important
+ * for the whole file.
*/
ssize_t
__blockdev_direct_IO(int rw, struct kiocb *iocb, struct inode *inode,
loff_t end = offset;
struct dio *dio;
struct dio_submit sdio = { 0, };
+ unsigned long user_addr;
+ size_t bytes;
+ struct buffer_head map_bh = { 0, };
if (rw & WRITE)
rw = WRITE_ODIRECT;
if (rw == READ && end == offset)
return 0;
- dio = kmalloc(sizeof(*dio), GFP_KERNEL);
+ dio = kmem_cache_alloc(dio_cache, GFP_KERNEL);
retval = -ENOMEM;
if (!dio)
goto out;
end - 1);
if (retval) {
mutex_unlock(&inode->i_mutex);
- kfree(dio);
+ kmem_cache_free(dio_cache, dio);
goto out;
}
}
dio->is_async = !is_sync_kiocb(iocb) && !((rw & WRITE) &&
(end > i_size_read(inode)));
- retval = direct_io_worker(rw, iocb, inode, iov, offset,
- nr_segs, blkbits, get_block, end_io,
- submit_io, dio, &sdio);
+ retval = 0;
+
+ dio->inode = inode;
+ dio->rw = rw;
+ sdio.blkbits = blkbits;
+ sdio.blkfactor = inode->i_blkbits - blkbits;
+ sdio.block_in_file = offset >> blkbits;
+
+ sdio.get_block = get_block;
+ dio->end_io = end_io;
+ 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);
+
+ spin_lock_init(&dio->bio_lock);
+ dio->refcount = 1;
+
+ /*
+ * In case of non-aligned buffers, we may need 2 more
+ * pages since we need to zero out first and last block.
+ */
+ if (unlikely(sdio.blkfactor))
+ sdio.pages_in_io = 2;
+
+ for (seg = 0; seg < nr_segs; seg++) {
+ user_addr = (unsigned long)iov[seg].iov_base;
+ 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;
+ sdio.size += bytes = iov[seg].iov_len;
+
+ /* Index into the first page of the first block */
+ sdio.first_block_in_page = (user_addr & ~PAGE_MASK) >> blkbits;
+ sdio.final_block_in_request = sdio.block_in_file +
+ (bytes >> blkbits);
+ /* Page fetching state */
+ sdio.head = 0;
+ sdio.tail = 0;
+ sdio.curr_page = 0;
+
+ sdio.total_pages = 0;
+ if (user_addr & (PAGE_SIZE-1)) {
+ sdio.total_pages++;
+ bytes -= PAGE_SIZE - (user_addr & (PAGE_SIZE - 1));
+ }
+ sdio.total_pages += (bytes + PAGE_SIZE - 1) / PAGE_SIZE;
+ sdio.curr_user_address = user_addr;
+
+ retval = do_direct_IO(dio, &sdio, &map_bh);
+
+ dio->result += iov[seg].iov_len -
+ ((sdio.final_block_in_request - sdio.block_in_file) <<
+ blkbits);
+
+ if (retval) {
+ dio_cleanup(dio, &sdio);
+ break;
+ }
+ } /* end iovec loop */
+
+ if (retval == -ENOTBLK) {
+ /*
+ * The remaining part of the request will be
+ * be handled by buffered I/O when we return
+ */
+ retval = 0;
+ }
+ /*
+ * 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, &sdio, 1, &map_bh);
+
+ if (sdio.cur_page) {
+ ssize_t ret2;
+
+ ret2 = dio_send_cur_page(dio, &sdio, &map_bh);
+ if (retval == 0)
+ retval = ret2;
+ page_cache_release(sdio.cur_page);
+ sdio.cur_page = NULL;
+ }
+ 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, &sdio);
+
+ /*
+ * All block lookups have been performed. For READ requests
+ * we can let i_mutex go now that its achieved its purpose
+ * of protecting us from looking up uninitialized blocks.
+ */
+ if (rw == READ && (dio->flags & DIO_LOCKING))
+ mutex_unlock(&dio->inode->i_mutex);
+
+ /*
+ * The only time we want to leave bios in flight is when a successful
+ * partial aio read or full aio write have been setup. In that case
+ * bio completion will call aio_complete. The only time it's safe to
+ * call aio_complete is when we return -EIOCBQUEUED, so we key on that.
+ * This had *better* be the only place that raises -EIOCBQUEUED.
+ */
+ BUG_ON(retval == -EIOCBQUEUED);
+ if (dio->is_async && retval == 0 && dio->result &&
+ ((rw & READ) || (dio->result == sdio.size)))
+ retval = -EIOCBQUEUED;
+
+ if (retval != -EIOCBQUEUED)
+ dio_await_completion(dio);
+
+ if (drop_refcount(dio) == 0) {
+ retval = dio_complete(dio, offset, retval, false);
+ kmem_cache_free(dio_cache, dio);
+ } else
+ BUG_ON(retval != -EIOCBQUEUED);
out:
return retval;
}
EXPORT_SYMBOL(__blockdev_direct_IO);
+
+static __init int dio_init(void)
+{
+ dio_cache = KMEM_CACHE(dio, SLAB_PANIC);
+ return 0;
+}
+module_init(dio_init)
git.openpandora.org / pandora-kernel.git / blobdiff