bcachefs: Fix an integer overflow

Fixes:

bcachefs (e7fdc10e-54a3-49d9-bd0c-390370889d84): disk usage increased 4294967296 more than 2823707312 sectors reserved)
transaction updates for __bchfs_fallocate journal seq 467859
  update: btree=extents cached=0 bch2_trans_update+0x4e8/0x540
    old u64s 5 type deleted 536925940:3559337304:4294967283 len 0 ver 0
    new u64s 6 type reservation 536925940:3559337304:4294967283 len 3559337304 ver 0: generation 0 replicas 2
  update: btree=inodes cached=1 bch2_extent_update_i_size_sectors+0x305/0x3b0
    old u64s 19 type inode_v3 0:536925940:4294967283 len 0 ver 0: mode 100600 flags 15300000 journal_seq 467859 bi_size 0 bi_sectors 0 bi_version 0 bi_atime 40905301656446 bi_ctime 40905301656446 bi_mtime 40905301656446 bi_otime 40905301656446 bi_uid 0 bi_gid 0 bi_nlink 0 bi_generation 0 bi_dev 0 bi_data_checksum 0 bi_compression 0 bi_project 0 bi_background_compression 0 bi_data_replicas 0 bi_promote_target 0 bi_foreground_target 0 bi_background_target 0 bi_erasure_code 0 bi_fields_set 0 bi_dir 1879048193 bi_dir_offset 3384856038735393365 bi_subvol 0 bi_parent_subvol 0 bi_nocow 0
    new u64s 19 type inode_v3 0:536925940:4294967283 len 0 ver 0: mode 100600 flags 15300000 journal_seq 467859 bi_size 0 bi_sectors 3559337304 bi_version 0 bi_atime 40905301656446 bi_ctime 40905301656446 bi_mtime 40905301656446 bi_otime 40905301656446 bi_uid 0 bi_gid 0 bi_nlink 0 bi_generation 0 bi_dev 0 bi_data_checksum 0 bi_compression 0 bi_project 0 bi_background_compression 0 bi_data_replicas 0 bi_promote_target 0 bi_foreground_target 0 bi_background_target 0 bi_erasure_code 0 bi_fields_set 0 bi_dir 1879048193 bi_dir_offset 3384856038735393365 bi_subvol 0 bi_parent_subvol 0 bi_nocow 0

Kernel panic - not syncing: bcachefs (e7fdc10e-54a3-49d9-bd0c-390370889d84): panic after error
CPU: 4 PID: 5154 Comm: rsync Not tainted 6.5.9-gateway-gca1614174cc0-dirty #1
Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./X570 Phantom Gaming 4, BIOS P4.20 08/02/2021
Call Trace:
 <TASK>
 dump_stack_lvl+0x5a/0x90
 panic+0x105/0x300
 ? console_unlock+0xf1/0x130
 ? bch2_printbuf_exit+0x16/0x30
 ? srso_return_thunk+0x5/0x10
 bch2_inconsistent_error+0x6f/0x80
 bch2_trans_fs_usage_apply+0x279/0x3d0
 __bch2_trans_commit+0x112a/0x1df0
 ? bch2_extent_update+0x13a/0x1d0
 bch2_extent_update+0x13a/0x1d0
 bch2_extent_fallocate+0x58e/0x740
 bch2_fallocate_dispatch+0xb7c/0x1030
 ? do_filp_open+0xa0/0x140
 vfs_fallocate+0x18e/0x1d0
 __x64_sys_fallocate+0x46/0x70
 do_syscall_64+0x48/0xa0
 ? exit_to_user_mode_prepare+0x4d/0xa0
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7fc85d91bbb3
Code: 64 89 02 b8 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 80 3d 31 da 0d 00 00 49 89 ca 74 14 b8 1d 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5d c3 0f 1f 40 00 48 83 ec 28 48 89 54 24 10

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/bcachefs/io_misc.c b/fs/bcachefs/io_misc.c
index 0979d5e05713..bebc11444ef5 100644
--- a/fs/bcachefs/io_misc.c
+++ b/fs/bcachefs/io_misc.c
@@ -23,7 +23,7 @@
 int bch2_extent_fallocate(struct btree_trans *trans,
 			  subvol_inum inum,
 			  struct btree_iter *iter,
-			  unsigned sectors,
+			  u64 sectors,
 			  struct bch_io_opts opts,
 			  s64 *i_sectors_delta,
 			  struct write_point_specifier write_point)
@@ -105,7 +105,7 @@ int bch2_extent_fallocate(struct btree_trans *trans,
 		if (ret)
 			goto err;
 
-		sectors = min(sectors, wp->sectors_free);
+		sectors = min_t(u64, sectors, wp->sectors_free);
 		sectors_allocated = sectors;
 
 		bch2_key_resize(&e->k, sectors);