]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - linux/blkdev.c
Disable pristine-tar option in gbp.conf, since there is no pristine-tar branch.
[bcachefs-tools-debian] / linux / blkdev.c
index 19aa88b8e0dcb93315b94e2e8d6db24410904ef6..b7f58737298fa7280f1c949312486c363f85ad14 100644 (file)
@@ -10,7 +10,9 @@
 
 #include <libaio.h>
 
+#ifdef CONFIG_VALGRIND
 #include <valgrind/memcheck.h>
+#endif
 
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 
 #include "tools-util.h"
 
+struct fops {
+       void (*init)(void);
+       void (*cleanup)(void);
+       void (*read)(struct bio *bio, struct iovec * iov, unsigned i);
+       void (*write)(struct bio *bio, struct iovec * iov, unsigned i);
+};
+
+static struct fops *fops;
 static io_context_t aio_ctx;
+static atomic_t running_requests;
 
 void generic_make_request(struct bio *bio)
 {
@@ -56,38 +67,19 @@ void generic_make_request(struct bio *bio)
                        .iov_len = len,
                };
 
+#ifdef CONFIG_VALGRIND
                /* To be pedantic it should only be on IO completion. */
                if (bio_op(bio) == REQ_OP_READ)
                        VALGRIND_MAKE_MEM_DEFINED(start, len);
+#endif
        }
 
-       struct iocb iocb = {
-               .data           = bio,
-               .aio_fildes     = bio->bi_opf & REQ_FUA
-                       ? bio->bi_bdev->bd_sync_fd
-                       : bio->bi_bdev->bd_fd,
-       }, *iocbp = &iocb;
-
        switch (bio_op(bio)) {
        case REQ_OP_READ:
-               iocb.aio_lio_opcode     = IO_CMD_PREADV;
-               iocb.u.v.vec            = iov;
-               iocb.u.v.nr             = i;
-               iocb.u.v.offset         = bio->bi_iter.bi_sector << 9;
-
-               ret = io_submit(aio_ctx, 1, &iocbp);
-               if (ret != 1)
-                       die("io_submit err: %s", strerror(-ret));
+               fops->read(bio, iov, i);
                break;
        case REQ_OP_WRITE:
-               iocb.aio_lio_opcode     = IO_CMD_PWRITEV;
-               iocb.u.v.vec            = iov;
-               iocb.u.v.nr             = i;
-               iocb.u.v.offset         = bio->bi_iter.bi_sector << 9;
-
-               ret = io_submit(aio_ctx, 1, &iocbp);
-               if (ret != 1)
-                       die("io_submit err: %s", strerror(-ret));
+               fops->write(bio, iov, i);
                break;
        case REQ_OP_FLUSH:
                ret = fsync(bio->bi_bdev->bd_fd);
@@ -121,11 +113,19 @@ int submit_bio_wait(struct bio *bio)
 
 int blkdev_issue_discard(struct block_device *bdev,
                         sector_t sector, sector_t nr_sects,
-                        gfp_t gfp_mask, unsigned long flags)
+                        gfp_t gfp_mask)
 {
        return 0;
 }
 
+int blkdev_issue_zeroout(struct block_device *bdev,
+                        sector_t sector, sector_t nr_sects,
+                        gfp_t gfp_mask, unsigned flags)
+{
+       /* Not yet implemented: */
+       BUG();
+}
+
 unsigned bdev_logical_block_size(struct block_device *bdev)
 {
        struct stat statbuf;
@@ -136,12 +136,10 @@ unsigned bdev_logical_block_size(struct block_device *bdev)
        BUG_ON(ret);
 
        if (!S_ISBLK(statbuf.st_mode))
-               return statbuf.st_blksize >> 9;
-
-       ret = ioctl(bdev->bd_fd, BLKPBSZGET, &blksize);
-       BUG_ON(ret);
+               return statbuf.st_blksize;
 
-       return blksize >> 9;
+       xioctl(bdev->bd_fd, BLKPBSZGET, &blksize);
+       return blksize;
 }
 
 sector_t get_capacity(struct gendisk *disk)
@@ -164,96 +162,142 @@ sector_t get_capacity(struct gendisk *disk)
        return bytes >> 9;
 }
 
-void blkdev_put(struct block_device *bdev, fmode_t mode)
+void bdev_release(struct bdev_handle *handle)
 {
-       fdatasync(bdev->bd_fd);
-       close(bdev->bd_sync_fd);
-       close(bdev->bd_fd);
-       free(bdev);
+       fdatasync(handle->bdev->bd_fd);
+       close(handle->bdev->bd_fd);
+       free(handle->bdev);
+       free(handle);
 }
 
-struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,
-                                       void *holder)
+struct bdev_handle *bdev_open_by_path(const char *path, blk_mode_t mode,
+                                     void *holder, const struct blk_holder_ops *hop)
 {
-       struct block_device *bdev;
-       int fd, sync_fd, flags = O_DIRECT;
+       int fd, flags = 0;
 
-       if ((mode & (FMODE_READ|FMODE_WRITE)) == (FMODE_READ|FMODE_WRITE))
+       if ((mode & (BLK_OPEN_READ|BLK_OPEN_WRITE)) == (BLK_OPEN_READ|BLK_OPEN_WRITE))
                flags = O_RDWR;
-       else if (mode & FMODE_READ)
+       else if (mode & BLK_OPEN_READ)
                flags = O_RDONLY;
-       else if (mode & FMODE_WRITE)
+       else if (mode & BLK_OPEN_WRITE)
                flags = O_WRONLY;
 
-#if 0
-       /* using O_EXCL doesn't work with opening twice for an O_SYNC fd: */
-       if (mode & FMODE_EXCL)
+       if (!(mode & BLK_OPEN_BUFFERED))
+               flags |= O_DIRECT;
+
+       if (mode & BLK_OPEN_EXCL)
                flags |= O_EXCL;
-#endif
 
        fd = open(path, flags);
        if (fd < 0)
                return ERR_PTR(-errno);
 
-       sync_fd = open(path, flags|O_SYNC);
-       if (sync_fd < 0) {
-               assert(0);
-               close(fd);
-               return ERR_PTR(-errno);
-       }
-
-       bdev = malloc(sizeof(*bdev));
+       struct block_device *bdev = malloc(sizeof(*bdev));
        memset(bdev, 0, sizeof(*bdev));
 
        strncpy(bdev->name, path, sizeof(bdev->name));
        bdev->name[sizeof(bdev->name) - 1] = '\0';
 
+       bdev->bd_dev            = xfstat(fd).st_rdev;
        bdev->bd_fd             = fd;
-       bdev->bd_sync_fd        = sync_fd;
        bdev->bd_holder         = holder;
        bdev->bd_disk           = &bdev->__bd_disk;
-       bdev->bd_bdi            = &bdev->__bd_bdi;
-       bdev->queue.backing_dev_info = bdev->bd_bdi;
+       bdev->bd_disk->bdi      = &bdev->bd_disk->__bdi;
+       bdev->queue.backing_dev_info = bdev->bd_disk->bdi;
 
-       return bdev;
+       struct bdev_handle *handle = calloc(sizeof(*handle), 1);
+       handle->bdev    = bdev;
+       handle->holder  = holder;
+       handle->mode    = mode;
+
+       return handle;
 }
 
-void bdput(struct block_device *bdev)
+int lookup_bdev(const char *path, dev_t *dev)
 {
-       BUG();
+       return -EINVAL;
 }
 
-struct block_device *lookup_bdev(const char *path)
+static void io_fallback(void)
 {
-       return ERR_PTR(-EINVAL);
+       fops++;
+       if (fops->init == NULL)
+               die("no fallback possible, something is very wrong");
+       fops->init();
 }
 
-static atomic_t aio_thread_stop;
+static void sync_check(struct bio *bio, int ret)
+{
+       if (ret != bio->bi_iter.bi_size) {
+               die("IO error: %s\n", strerror(-ret));
+       }
+
+       if (bio->bi_opf & REQ_FUA) {
+               ret = fdatasync(bio->bi_bdev->bd_fd);
+               if (ret)
+                       die("fsync error: %s\n", strerror(-ret));
+       }
+       bio_endio(bio);
+}
+
+static void sync_init(void) {}
+
+static void sync_cleanup(void)
+{
+       /* not necessary? */
+       sync();
+}
+
+static void sync_read(struct bio *bio, struct iovec * iov, unsigned i)
+{
+
+       ssize_t ret = preadv(bio->bi_bdev->bd_fd, iov, i,
+                            bio->bi_iter.bi_sector << 9);
+       sync_check(bio, ret);
+}
+
+static void sync_write(struct bio *bio, struct iovec * iov, unsigned i)
+{
+       ssize_t ret = pwritev2(bio->bi_bdev->bd_fd, iov, i,
+                              bio->bi_iter.bi_sector << 9,
+                              bio->bi_opf & REQ_FUA ? RWF_SYNC : 0);
+       sync_check(bio, ret);
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(aio_events_completed);
 
 static int aio_completion_thread(void *arg)
 {
        struct io_event events[8], *ev;
        int ret;
+       bool stop = false;
 
-       while (1) {
+       while (!stop) {
                ret = io_getevents(aio_ctx, 1, ARRAY_SIZE(events),
                                   events, NULL);
 
-               if (atomic_read(&aio_thread_stop))
-                       break;
-
                if (ret < 0 && ret == -EINTR)
                        continue;
                if (ret < 0)
                        die("io_getevents() error: %s", strerror(-ret));
+               if (ret)
+                       wake_up(&aio_events_completed);
 
                for (ev = events; ev < events + ret; ev++) {
                        struct bio *bio = (struct bio *) ev->data;
 
+                       /* This should only happen during blkdev_cleanup() */
+                       if (!bio) {
+                               BUG_ON(atomic_read(&running_requests) != 0);
+                               stop = true;
+                               continue;
+                       }
+
                        if (ev->res != bio->bi_iter.bi_size)
                                bio->bi_status = BLK_STS_IOERR;
 
                        bio_endio(bio);
+                       atomic_dec(&running_requests);
                }
        }
 
@@ -262,29 +306,29 @@ static int aio_completion_thread(void *arg)
 
 static struct task_struct *aio_task = NULL;
 
-__attribute__((constructor(102)))
-static void blkdev_init(void)
+static void aio_init(void)
 {
        struct task_struct *p;
+       long err = io_setup(256, &aio_ctx);
+       if (!err) {
+               p = kthread_run(aio_completion_thread, NULL, "aio_completion");
+               BUG_ON(IS_ERR(p));
 
-       if (io_setup(256, &aio_ctx))
-               die("io_setup() error: %m");
+               aio_task = p;
 
-       p = kthread_run(aio_completion_thread, NULL, "aio_completion");
-       BUG_ON(IS_ERR(p));
-
-       aio_task = p;
+       } else if (err == -ENOSYS) {
+               io_fallback();
+       } else {
+               die("io_setup() error: %s", strerror(err));
+       }
 }
 
-__attribute__((destructor(102)))
-static void blkdev_cleanup(void)
+static void aio_cleanup(void)
 {
        struct task_struct *p = NULL;
        swap(aio_task, p);
        get_task_struct(p);
 
-       atomic_set(&aio_thread_stop, 1);
-
        /* I mean, really?! IO_CMD_NOOP is even defined, but not implemented. */
        int fds[2];
        int ret = pipe(fds);
@@ -295,6 +339,7 @@ static void blkdev_cleanup(void)
        int junk = 0;
        struct iocb iocb = {
                .aio_lio_opcode = IO_CMD_PWRITE,
+               .data = NULL, /* Signal to stop */
                .aio_fildes = fds[1],
                .u.c.buf = &junk,
                .u.c.nbytes = 1,
@@ -311,3 +356,73 @@ static void blkdev_cleanup(void)
        close(fds[0]);
        close(fds[1]);
 }
+
+static void aio_op(struct bio *bio, struct iovec *iov, unsigned i, int opcode)
+{
+       ssize_t ret;
+       struct iocb iocb = {
+               .data           = bio,
+               .aio_fildes     = bio->bi_bdev->bd_fd,
+               .aio_rw_flags   = bio->bi_opf & REQ_FUA ? RWF_SYNC : 0,
+               .aio_lio_opcode = opcode,
+               .u.c.buf        = iov,
+               .u.c.nbytes     = i,
+               .u.c.offset     = bio->bi_iter.bi_sector << 9,
+
+       }, *iocbp = &iocb;
+
+       atomic_inc(&running_requests);
+
+       wait_event(aio_events_completed,
+                  (ret = io_submit(aio_ctx, 1, &iocbp)) != -EAGAIN);;
+
+       if (ret != 1)
+               die("io_submit err: %s", strerror(-ret));
+}
+
+static void aio_read(struct bio *bio, struct iovec *iov, unsigned i)
+{
+       aio_op(bio, iov, i, IO_CMD_PREADV);
+}
+
+static void aio_write(struct bio *bio, struct iovec * iov, unsigned i)
+{
+       aio_op(bio, iov, i, IO_CMD_PWRITEV);
+}
+
+
+/* not implemented */
+static void uring_init(void) {
+       io_fallback();
+}
+
+struct fops fops_list[] = {
+       {
+               .init           = uring_init,
+       }, {
+               .init           = aio_init,
+               .cleanup        = aio_cleanup,
+               .read           = aio_read,
+               .write          = aio_write,
+       }, {
+               .init           = sync_init,
+               .cleanup        = sync_cleanup,
+               .read           = sync_read,
+               .write          = sync_write,
+       }, {
+               /* NULL */
+       }
+};
+
+__attribute__((constructor(102)))
+static void blkdev_init(void)
+{
+       fops = fops_list;
+       fops->init();
+}
+
+__attribute__((destructor(102)))
+static void blkdev_cleanup(void)
+{
+       fops->cleanup();
+}