The data repair function of direct read will be implemented later, and some code
in bio_readpage_error will be reused, so split bio_readpage_error into
several functions which will be used in direct read repair later.
Signed-off-by: Miao Xie <mi...@cn.fujitsu.com>
---
Changelog v1 -> v4:
- None
---
fs/btrfs/extent_io.c | 159 ++++++++++++++++++++++++++++++---------------------
fs/btrfs/extent_io.h | 28 +++++++++
2 files changed, 123 insertions(+), 64 deletions(-)
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 154cb8e..cf1de40 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -1962,25 +1962,6 @@ static void check_page_uptodate(struct extent_io_tree
*tree, struct page *page)
SetPageUptodate(page);
}
-/*
- * When IO fails, either with EIO or csum verification fails, we
- * try other mirrors that might have a good copy of the data. This
- * io_failure_record is used to record state as we go through all the
- * mirrors. If another mirror has good data, the page is set up to date
- * and things continue. If a good mirror can't be found, the original
- * bio end_io callback is called to indicate things have failed.
- */
-struct io_failure_record {
- struct page *page;
- u64 start;
- u64 len;
- u64 logical;
- unsigned long bio_flags;
- int this_mirror;
- int failed_mirror;
- int in_validation;
-};
-
static int free_io_failure(struct inode *inode, struct io_failure_record *rec)
{
int ret;
@@ -2156,40 +2137,24 @@ out:
return 0;
}
-/*
- * this is a generic handler for readpage errors (default
- * readpage_io_failed_hook). if other copies exist, read those and write back
- * good data to the failed position. does not investigate in remapping the
- * failed extent elsewhere, hoping the device will be smart enough to do this
as
- * needed
- */
-
-static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
- struct page *page, u64 start, u64 end,
- int failed_mirror)
+int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
+ struct io_failure_record **failrec_ret)
{
- struct io_failure_record *failrec = NULL;
+ struct io_failure_record *failrec;
u64 private;
struct extent_map *em;
- struct inode *inode = page->mapping->host;
struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
- struct bio *bio;
- struct btrfs_io_bio *btrfs_failed_bio;
- struct btrfs_io_bio *btrfs_bio;
- int num_copies;
int ret;
- int read_mode;
u64 logical;
- BUG_ON(failed_bio->bi_rw & REQ_WRITE);
-
ret = get_state_private(failure_tree, start, &private);
if (ret) {
failrec = kzalloc(sizeof(*failrec), GFP_NOFS);
if (!failrec)
return -ENOMEM;
+
failrec->start = start;
failrec->len = end - start + 1;
failrec->this_mirror = 0;
@@ -2209,11 +2174,11 @@ static int bio_readpage_error(struct bio *failed_bio,
u64 phy_offset,
em = NULL;
}
read_unlock(&em_tree->lock);
-
if (!em) {
kfree(failrec);
return -EIO;
}
+
logical = start - em->start;
logical = em->block_start + logical;
if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
@@ -2222,8 +2187,10 @@ static int bio_readpage_error(struct bio *failed_bio,
u64 phy_offset,
extent_set_compress_type(&failrec->bio_flags,
em->compress_type);
}
- pr_debug("bio_readpage_error: (new) logical=%llu, start=%llu, "
- "len=%llu\n", logical, start, failrec->len);
+
+ pr_debug("Get IO Failure Record: (new) logical=%llu,
start=%llu, len=%llu\n",
+ logical, start, failrec->len);
+
failrec->logical = logical;
free_extent_map(em);
@@ -2243,8 +2210,7 @@ static int bio_readpage_error(struct bio *failed_bio, u64
phy_offset,
}
} else {
failrec = (struct io_failure_record *)(unsigned long)private;
- pr_debug("bio_readpage_error: (found) logical=%llu, "
- "start=%llu, len=%llu, validation=%d\n",
+ pr_debug("Get IO Failure Record: (found) logical=%llu,
start=%llu, len=%llu, validation=%d\n",
failrec->logical, failrec->start, failrec->len,
failrec->in_validation);
/*
@@ -2253,6 +2219,17 @@ static int bio_readpage_error(struct bio *failed_bio,
u64 phy_offset,
* clean_io_failure() clean all those errors at once.
*/
}
+
+ *failrec_ret = failrec;
+
+ return 0;
+}
+
+int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
+ struct io_failure_record *failrec, int failed_mirror)
+{
+ int num_copies;
+
num_copies = btrfs_num_copies(BTRFS_I(inode)->root->fs_info,
failrec->logical, failrec->len);
if (num_copies == 1) {
@@ -2261,10 +2238,9 @@ static int bio_readpage_error(struct bio *failed_bio,
u64 phy_offset,
* all the retry and error correction code that follows. no
* matter what the error is, it is very likely to persist.
*/
- pr_debug("bio_readpage_error: cannot repair, num_copies=%d,
next_mirror %d, failed_mirror %d\n",
+ pr_debug("Check Repairable: cannot repair, num_copies=%d,
next_mirror %d, failed_mirror %d\n",
num_copies, failrec->this_mirror, failed_mirror);
- free_io_failure(inode, failrec);
- return -EIO;
+ return 0;
}
/*
@@ -2284,7 +2260,6 @@ static int bio_readpage_error(struct bio *failed_bio, u64
phy_offset,
BUG_ON(failrec->in_validation);
failrec->in_validation = 1;
failrec->this_mirror = failed_mirror;
- read_mode = READ_SYNC | REQ_FAILFAST_DEV;
} else {
/*
* we're ready to fulfill a) and b) alongside. get a good copy
@@ -2300,22 +2275,32 @@ static int bio_readpage_error(struct bio *failed_bio,
u64 phy_offset,
failrec->this_mirror++;
if (failrec->this_mirror == failed_mirror)
failrec->this_mirror++;
- read_mode = READ_SYNC;
}
if (failrec->this_mirror > num_copies) {
- pr_debug("bio_readpage_error: (fail) num_copies=%d, next_mirror
%d, failed_mirror %d\n",
+ pr_debug("Check Repairable: (fail) num_copies=%d, next_mirror
%d, failed_mirror %d\n",
num_copies, failrec->this_mirror, failed_mirror);
- free_io_failure(inode, failrec);
- return -EIO;
+ return 0;
}
+ return 1;
+}
+
+
+struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio
*failed_bio,
+ struct io_failure_record *failrec,
+ struct page *page, int pg_offset, int icsum,
+ bio_end_io_t *endio_func)
+{
+ struct bio *bio;
+ struct btrfs_io_bio *btrfs_failed_bio;
+ struct btrfs_io_bio *btrfs_bio;
+
bio = btrfs_io_bio_alloc(GFP_NOFS, 1);
- if (!bio) {
- free_io_failure(inode, failrec);
- return -EIO;
- }
- bio->bi_end_io = failed_bio->bi_end_io;
+ if (!bio)
+ return NULL;
+
+ bio->bi_end_io = endio_func;
bio->bi_iter.bi_sector = failrec->logical >> 9;
bio->bi_bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
bio->bi_iter.bi_size = 0;
@@ -2327,17 +2312,63 @@ static int bio_readpage_error(struct bio *failed_bio,
u64 phy_offset,
btrfs_bio = btrfs_io_bio(bio);
btrfs_bio->csum = btrfs_bio->csum_inline;
- phy_offset >>= inode->i_sb->s_blocksize_bits;
- phy_offset *= csum_size;
- memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + phy_offset,
+ icsum *= csum_size;
+ memcpy(btrfs_bio->csum, btrfs_failed_bio->csum + icsum,
csum_size);
}
- bio_add_page(bio, page, failrec->len, start - page_offset(page));
+ bio_add_page(bio, page, failrec->len, pg_offset);
+
+ return bio;
+}
+
+/*
+ * this is a generic handler for readpage errors (default
+ * readpage_io_failed_hook). if other copies exist, read those and write back
+ * good data to the failed position. does not investigate in remapping the
+ * failed extent elsewhere, hoping the device will be smart enough to do this
as
+ * needed
+ */
+
+static int bio_readpage_error(struct bio *failed_bio, u64 phy_offset,
+ struct page *page, u64 start, u64 end,
+ int failed_mirror)
+{
+ struct io_failure_record *failrec;
+ struct inode *inode = page->mapping->host;
+ struct extent_io_tree *tree = &BTRFS_I(inode)->io_tree;
+ struct bio *bio;
+ int read_mode;
+ int ret;
+
+ BUG_ON(failed_bio->bi_rw & REQ_WRITE);
+
+ ret = btrfs_get_io_failure_record(inode, start, end, &failrec);
+ if (ret)
+ return ret;
+
+ ret = btrfs_check_repairable(inode, failed_bio, failrec, failed_mirror);
+ if (!ret) {
+ free_io_failure(inode, failrec);
+ return -EIO;
+ }
+
+ if (failed_bio->bi_vcnt > 1)
+ read_mode = READ_SYNC | REQ_FAILFAST_DEV;
+ else
+ read_mode = READ_SYNC;
+
+ phy_offset >>= inode->i_sb->s_blocksize_bits;
+ bio = btrfs_create_repair_bio(inode, failed_bio, failrec, page,
+ start - page_offset(page),
+ (int)phy_offset, failed_bio->bi_end_io);
+ if (!bio) {
+ free_io_failure(inode, failrec);
+ return -EIO;
+ }
- pr_debug("bio_readpage_error: submitting new read[%#x] to "
- "this_mirror=%d, num_copies=%d, in_validation=%d\n", read_mode,
- failrec->this_mirror, num_copies, failrec->in_validation);
+ pr_debug("Repair Read Error: submitting new read[%#x] to
this_mirror=%d, in_validation=%d\n",
+ read_mode, failrec->this_mirror, failrec->in_validation);
ret = tree->ops->submit_bio_hook(inode, read_mode, bio,
failrec->this_mirror,
diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h
index 844b4c5..75b621b 100644
--- a/fs/btrfs/extent_io.h
+++ b/fs/btrfs/extent_io.h
@@ -344,6 +344,34 @@ int repair_io_failure(struct btrfs_fs_info *fs_info, u64
start,
int end_extent_writepage(struct page *page, int err, u64 start, u64 end);
int repair_eb_io_failure(struct btrfs_root *root, struct extent_buffer *eb,
int mirror_num);
+
+/*
+ * When IO fails, either with EIO or csum verification fails, we
+ * try other mirrors that might have a good copy of the data. This
+ * io_failure_record is used to record state as we go through all the
+ * mirrors. If another mirror has good data, the page is set up to date
+ * and things continue. If a good mirror can't be found, the original
+ * bio end_io callback is called to indicate things have failed.
+ */
+struct io_failure_record {
+ struct page *page;
+ u64 start;
+ u64 len;
+ u64 logical;
+ unsigned long bio_flags;
+ int this_mirror;
+ int failed_mirror;
+ int in_validation;
+};
+
+int btrfs_get_io_failure_record(struct inode *inode, u64 start, u64 end,
+ struct io_failure_record **failrec_ret);
+int btrfs_check_repairable(struct inode *inode, struct bio *failed_bio,
+ struct io_failure_record *failrec, int fail_mirror);
+struct bio *btrfs_create_repair_bio(struct inode *inode, struct bio
*failed_bio,
+ struct io_failure_record *failrec,
+ struct page *page, int pg_offset, int icsum,
+ bio_end_io_t *endio_func);
#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS
noinline u64 find_lock_delalloc_range(struct inode *inode,
struct extent_io_tree *tree,
--
1.9.3
--
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