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bcachefs: Fix bch2_inode_delete_keys() 

bch2_inode_delete_keys() was using BTREE_ITER_NOT_EXTENTS, on the
assumption that it would never need to split extents.

But that caused a race with extents being split by other threads -
specifically, the data move path. Extents iterators have the iterator
position pointing to the start of the extent, which avoids the race.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2023-09-27 14:44:56 -04:00
parent 7dcf62c06d
commit 4220666398
1 changed files with 8 additions and 2 deletions
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10
fs/bcachefs/inode.c
View File

@ -780,6 +780,7 @@ static int bch2_inode_delete_keys(struct btree_trans *trans,
struct btree_iter iter;
struct bkey_s_c k;
struct bkey_i delete;
struct bpos end = POS(inum.inum, U64_MAX);
u32 snapshot;
int ret = 0;
@ -788,7 +789,7 @@ static int bch2_inode_delete_keys(struct btree_trans *trans,
* extent iterator:
*/
bch2_trans_iter_init(trans, &iter, id, POS(inum.inum, 0),
BTREE_ITER_INTENT|BTREE_ITER_NOT_EXTENTS);
BTREE_ITER_INTENT);
while (1) {
bch2_trans_begin(trans);
@ -799,7 +800,7 @@ static int bch2_inode_delete_keys(struct btree_trans *trans,
bch2_btree_iter_set_snapshot(&iter, snapshot);
k = bch2_btree_iter_peek_upto(&iter, POS(inum.inum, U64_MAX));
k = bch2_btree_iter_peek_upto(&iter, end);
ret = bkey_err(k);
if (ret)
goto err;
@ -810,6 +811,11 @@ static int bch2_inode_delete_keys(struct btree_trans *trans,
bkey_init(&delete.k);
delete.k.p = iter.pos;
if (iter.flags & BTREE_ITER_IS_EXTENTS)
bch2_key_resize(&delete.k,
bpos_min(end, k.k->p).offset -
iter.pos.offset);
ret = bch2_trans_update(trans, &iter, &delete, 0) ?:
bch2_trans_commit(trans, NULL, NULL,
BTREE_INSERT_NOFAIL);