[PATCH] bcachefs: Return -ENOKEY/EINVAL when mount decryption fails
From: Chris Webb <hidden>
Date: 2021-11-04 21:03:21
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
bch2_fs_encryption_init() correctly passes back -ENOKEY from request_key()
when no unlock key is found, or -EINVAL if superblock decryption fails
because of an invalid key. However, these get absorbed into a generic NULL
return from bch2_fs_alloc() and later returned to user space as -ENOMEM,
leading to a misleading error from mount(1):
mount(2) system call failed: Out of memory.
Return explicit error pointers out of bch2_fs_alloc() and handle them in
both callers, so the user instead sees
mount(2) system call failed: Required key not available.
when attempting to mount a filesystem which is still locked.
Signed-off-by: Chris Webb <redacted>
---
Notes:
v1: Generated to apply against v5.13 bcachefs kernel (2021-10-14)
v2: Updated to apply against v5.15 bcachefs kernel (2021-11-04)
fs/bcachefs/super.c | 51 ++++++++++++++++++++++++++++++---------------
1 file changed, 34 insertions(+), 17 deletions(-)
diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c
index dc8f641504be..9cd296feb312 100644
--- a/fs/bcachefs/super.c
+++ b/fs/bcachefs/super.c@@ -638,12 +638,15 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts) struct bch_fs *c; unsigned i, iter_size; const char *err; + int ret = 0; pr_verbose_init(opts, ""); c = kvpmalloc(sizeof(struct bch_fs), GFP_KERNEL|__GFP_ZERO); - if (!c) + if (!c) { + c = ERR_PTR(-ENOMEM); goto out; + } __module_get(THIS_MODULE);
@@ -724,13 +727,16 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts) mutex_init(&c->sectors_available_lock); - if (percpu_init_rwsem(&c->mark_lock)) + if (percpu_init_rwsem(&c->mark_lock)) { + ret = -ENOMEM; goto err; + } mutex_lock(&c->sb_lock); if (bch2_sb_to_fs(c, sb)) { mutex_unlock(&c->sb_lock); + ret = -ENOMEM; goto err; }
@@ -745,8 +751,10 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts) c->block_bits = ilog2(c->opts.block_size); c->btree_foreground_merge_threshold = BTREE_FOREGROUND_MERGE_THRESHOLD(c); - if (bch2_fs_init_fault("fs_alloc")) + if (bch2_fs_init_fault("fs_alloc")) { + ret = -ENOMEM; goto err; + } iter_size = sizeof(struct sort_iter) + (btree_blocks(c) + 1) * 2 *
@@ -787,10 +795,15 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts) bch2_fs_btree_interior_update_init(c) || bch2_fs_subvolumes_init(c) || bch2_fs_io_init(c) || - bch2_fs_encryption_init(c) || bch2_fs_compress_init(c) || bch2_fs_ec_init(c) || - bch2_fs_fsio_init(c)) + bch2_fs_fsio_init(c)) { + ret = -ENOMEM; + goto err; + } + + ret = bch2_fs_encryption_init(c); + if (ret) goto err; if (c->opts.nochanges)
@@ -799,8 +812,10 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts) mi = bch2_sb_get_members(c->disk_sb.sb); for (i = 0; i < c->sb.nr_devices; i++) if (bch2_dev_exists(c->disk_sb.sb, mi, i) && - bch2_dev_alloc(c, i)) + bch2_dev_alloc(c, i)) { + ret = -ENOMEM; goto err; + } bch2_journal_entry_res_resize(&c->journal, &c->btree_root_journal_res,
@@ -815,14 +830,15 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts) mutex_unlock(&bch_fs_list_lock); if (err) { bch_err(c, "bch2_fs_online() error: %s", err); + ret = -ENOMEM; goto err; } out: - pr_verbose_init(opts, "ret %i", c ? 0 : -ENOMEM); + pr_verbose_init(opts, "ret %i", PTR_ERR_OR_ZERO(c)); return c; err: bch2_fs_free(c); - c = NULL; + c = ERR_PTR(ret); goto out; }
@@ -1939,10 +1955,11 @@ struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices, i++; } - ret = -ENOMEM; c = bch2_fs_alloc(sb[best_sb].sb, opts); - if (!c) + if (IS_ERR(c)) { + ret = PTR_ERR(c); goto err; + } err = "bch2_dev_online() error"; down_write(&c->state_lock);
@@ -1973,7 +1990,7 @@ struct bch_fs *bch2_fs_open(char * const *devices, unsigned nr_devices, devices[0], err); ret = -EINVAL; err: - if (c) + if (!IS_ERR_OR_NULL(c)) bch2_fs_stop(c); for (i = 0; i < nr_devices; i++) bch2_free_super(&sb[i]);
@@ -2002,12 +2019,12 @@ static const char *__bch2_fs_open_incremental(struct bch_sb_handle *sb, if (err) goto err; } else { - c = bch2_fs_alloc(sb->sb, opts); - err = "cannot allocate memory"; - if (!c) - goto err; - allocated_fs = true; + c = bch2_fs_alloc(sb->sb, opts); + + err = "bch2_fs_alloc() error"; + if (IS_ERR(c)) + goto err; } err = "bch2_dev_online() error";
@@ -2033,7 +2050,7 @@ static const char *__bch2_fs_open_incremental(struct bch_sb_handle *sb, err: mutex_unlock(&bch_fs_list_lock); - if (allocated_fs) + if (allocated_fs && !IS_ERR(c)) bch2_fs_stop(c); else if (c) closure_put(&c->cl);