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-rw-r--r--fs/btrfs/inode.c205
1 files changed, 184 insertions, 21 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 8c027aa0020a..a47e4faa8c46 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5535,13 +5535,21 @@ struct btrfs_dio_private {
u64 bytes;
u32 *csums;
void *private;
+
+ /* number of bios pending for this dio */
+ atomic_t pending_bios;
+
+ /* IO errors */
+ int errors;
+
+ struct bio *orig_bio;
};
static void btrfs_endio_direct_read(struct bio *bio, int err)
{
+ struct btrfs_dio_private *dip = bio->bi_private;
struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
struct bio_vec *bvec = bio->bi_io_vec;
- struct btrfs_dio_private *dip = bio->bi_private;
struct inode *inode = dip->inode;
struct btrfs_root *root = BTRFS_I(inode)->root;
u64 start;
@@ -5684,6 +5692,176 @@ static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
return 0;
}
+static void btrfs_end_dio_bio(struct bio *bio, int err)
+{
+ struct btrfs_dio_private *dip = bio->bi_private;
+
+ if (err) {
+ printk(KERN_ERR "btrfs direct IO failed ino %lu rw %lu "
+ "disk_bytenr %lu len %u err no %d\n",
+ dip->inode->i_ino, bio->bi_rw, bio->bi_sector,
+ bio->bi_size, err);
+ dip->errors = 1;
+
+ /*
+ * before atomic variable goto zero, we must make sure
+ * dip->errors is perceived to be set.
+ */
+ smp_mb__before_atomic_dec();
+ }
+
+ /* if there are more bios still pending for this dio, just exit */
+ if (!atomic_dec_and_test(&dip->pending_bios))
+ goto out;
+
+ if (dip->errors)
+ bio_io_error(dip->orig_bio);
+ else {
+ set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
+ bio_endio(dip->orig_bio, 0);
+ }
+out:
+ bio_put(bio);
+}
+
+static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
+ u64 first_sector, gfp_t gfp_flags)
+{
+ int nr_vecs = bio_get_nr_vecs(bdev);
+ return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
+}
+
+static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
+ int rw, u64 file_offset, int skip_sum,
+ u32 *csums)
+{
+ int write = rw & REQ_WRITE;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret;
+
+ bio_get(bio);
+ ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
+ if (ret)
+ goto err;
+
+ if (write && !skip_sum) {
+ ret = btrfs_wq_submit_bio(root->fs_info,
+ inode, rw, bio, 0, 0,
+ file_offset,
+ __btrfs_submit_bio_start_direct_io,
+ __btrfs_submit_bio_done);
+ goto err;
+ } else if (!skip_sum)
+ btrfs_lookup_bio_sums_dio(root, inode, bio,
+ file_offset, csums);
+
+ ret = btrfs_map_bio(root, rw, bio, 0, 1);
+err:
+ bio_put(bio);
+ return ret;
+}
+
+static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
+ int skip_sum)
+{
+ struct inode *inode = dip->inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
+ struct bio *bio;
+ struct bio *orig_bio = dip->orig_bio;
+ struct bio_vec *bvec = orig_bio->bi_io_vec;
+ u64 start_sector = orig_bio->bi_sector;
+ u64 file_offset = dip->logical_offset;
+ u64 submit_len = 0;
+ u64 map_length;
+ int nr_pages = 0;
+ u32 *csums = dip->csums;
+ int ret = 0;
+
+ bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
+ if (!bio)
+ return -ENOMEM;
+ bio->bi_private = dip;
+ bio->bi_end_io = btrfs_end_dio_bio;
+ atomic_inc(&dip->pending_bios);
+
+ map_length = orig_bio->bi_size;
+ ret = btrfs_map_block(map_tree, READ, start_sector << 9,
+ &map_length, NULL, 0);
+ if (ret) {
+ bio_put(bio);
+ return -EIO;
+ }
+
+ while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
+ if (unlikely(map_length < submit_len + bvec->bv_len ||
+ bio_add_page(bio, bvec->bv_page, bvec->bv_len,
+ bvec->bv_offset) < bvec->bv_len)) {
+ /*
+ * inc the count before we submit the bio so
+ * we know the end IO handler won't happen before
+ * we inc the count. Otherwise, the dip might get freed
+ * before we're done setting it up
+ */
+ atomic_inc(&dip->pending_bios);
+ ret = __btrfs_submit_dio_bio(bio, inode, rw,
+ file_offset, skip_sum,
+ csums);
+ if (ret) {
+ bio_put(bio);
+ atomic_dec(&dip->pending_bios);
+ goto out_err;
+ }
+
+ if (!skip_sum)
+ csums = csums + nr_pages;
+ start_sector += submit_len >> 9;
+ file_offset += submit_len;
+
+ submit_len = 0;
+ nr_pages = 0;
+
+ bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
+ start_sector, GFP_NOFS);
+ if (!bio)
+ goto out_err;
+ bio->bi_private = dip;
+ bio->bi_end_io = btrfs_end_dio_bio;
+
+ map_length = orig_bio->bi_size;
+ ret = btrfs_map_block(map_tree, READ, start_sector << 9,
+ &map_length, NULL, 0);
+ if (ret) {
+ bio_put(bio);
+ goto out_err;
+ }
+ } else {
+ submit_len += bvec->bv_len;
+ nr_pages ++;
+ bvec++;
+ }
+ }
+
+ ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
+ csums);
+ if (!ret)
+ return 0;
+
+ bio_put(bio);
+out_err:
+ dip->errors = 1;
+ /*
+ * before atomic variable goto zero, we must
+ * make sure dip->errors is perceived to be set.
+ */
+ smp_mb__before_atomic_dec();
+ if (atomic_dec_and_test(&dip->pending_bios))
+ bio_io_error(dip->orig_bio);
+
+ /* bio_end_io() will handle error, so we needn't return it */
+ return 0;
+}
+
static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
loff_t file_offset)
{
@@ -5723,33 +5901,18 @@ static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
dip->disk_bytenr = (u64)bio->bi_sector << 9;
bio->bi_private = dip;
+ dip->errors = 0;
+ dip->orig_bio = bio;
+ atomic_set(&dip->pending_bios, 0);
if (write)
bio->bi_end_io = btrfs_endio_direct_write;
else
bio->bi_end_io = btrfs_endio_direct_read;
- ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
- if (ret)
- goto free_ordered;
-
- if (write && !skip_sum) {
- ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
- inode, rw, bio, 0, 0,
- dip->logical_offset,
- __btrfs_submit_bio_start_direct_io,
- __btrfs_submit_bio_done);
- if (ret)
- goto free_ordered;
+ ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
+ if (!ret)
return;
- } else if (!skip_sum)
- btrfs_lookup_bio_sums_dio(root, inode, bio,
- dip->logical_offset, dip->csums);
-
- ret = btrfs_map_bio(root, rw, bio, 0, 1);
- if (ret)
- goto free_ordered;
- return;
free_ordered:
/*
* If this is a write, we need to clean up the reserved space and kill
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.