Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-21 19:41:42 +00:00
Code Issues Packages Projects Releases Wiki Activity

bcachefs: On device add, prefer unused slots

Browse Source 
We can't strictly guarantee that no pointers refer to nonexistent
devices - we attempt to, but we need to be safe when the filesystem is
corrupt.

Therefore, change device_add to try to pick a slot that's never been
used, or the slot that's been unused the longest.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2024-04-30 04:24:58 -04:00
parent ffcbec6076
commit 3a718c0647
1 changed files with 22 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

25
fs/bcachefs/super.c
View File

@ -1764,9 +1764,28 @@ int bch2_dev_add(struct bch_fs *c, const char *path)
if (dynamic_fault("bcachefs:add:no_slot"))
goto no_slot;
for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++)
if (!bch2_member_exists(c->disk_sb.sb, dev_idx))
goto have_slot;
if (c->sb.nr_devices < BCH_SB_MEMBERS_MAX) {
dev_idx = c->sb.nr_devices;
goto have_slot;
}
int best = -1;
u64 best_last_mount = 0;
for (dev_idx = 0; dev_idx < BCH_SB_MEMBERS_MAX; dev_idx++) {
struct bch_member m = bch2_sb_member_get(c->disk_sb.sb, dev_idx);
if (bch2_member_alive(&m))
continue;
u64 last_mount = le64_to_cpu(m.last_mount);
if (best < 0 || last_mount < best_last_mount) {
best = dev_idx;
best_last_mount = last_mount;
}
}
if (best >= 0) {
dev_idx = best;
goto have_slot;
}
no_slot:
ret = -BCH_ERR_ENOSPC_sb_members;
bch_err_msg(c, ret, "setting up new superblock");