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authorLinus Torvalds <torvalds@linux-foundation.org>2020-11-27 23:42:13 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2020-11-27 23:42:13 +0300
commita17a3ca55e96d20e25e8b1a7cd08192ce2bac3cc (patch)
treea690de46e6c2c6f67562e7a185a64d4fad67cb81 /fs
parentd41e9b22eb871a7a7060964db9ce1ceb1c6e5b57 (diff)
parenta855fbe69229078cd8aecd8974fb996a5ca651e6 (diff)
downloadlinux-a17a3ca55e96d20e25e8b1a7cd08192ce2bac3cc.tar.xz
Merge tag 'for-5.10-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba: "A few fixes for various warnings that accumulated over past two weeks: - tree-checker: add missing return values for some errors - lockdep fixes - when reading qgroup config and starting quota rescan - reverse order of quota ioctl lock and VFS freeze lock - avoid accessing potentially stale fs info during device scan, reported by syzbot - add scope NOFS protection around qgroup relation changes - check for running transaction before flushing qgroups - fix tracking of new delalloc ranges for some cases" * tag 'for-5.10-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix lockdep splat when enabling and disabling qgroups btrfs: do nofs allocations when adding and removing qgroup relations btrfs: fix lockdep splat when reading qgroup config on mount btrfs: tree-checker: add missing returns after data_ref alignment checks btrfs: don't access possibly stale fs_info data for printing duplicate device btrfs: tree-checker: add missing return after error in root_item btrfs: qgroup: don't commit transaction when we already hold the handle btrfs: fix missing delalloc new bit for new delalloc ranges
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/ctree.h5
-rw-r--r--fs/btrfs/file.c57
-rw-r--r--fs/btrfs/inode.c58
-rw-r--r--fs/btrfs/qgroup.c88
-rw-r--r--fs/btrfs/tests/inode-tests.c12
-rw-r--r--fs/btrfs/tree-checker.c3
-rw-r--r--fs/btrfs/volumes.c8
7 files changed, 158 insertions, 73 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 0378933d163c..0b29bdb25105 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -878,7 +878,10 @@ struct btrfs_fs_info {
*/
struct ulist *qgroup_ulist;
- /* protect user change for quota operations */
+ /*
+ * Protect user change for quota operations. If a transaction is needed,
+ * it must be started before locking this lock.
+ */
struct mutex qgroup_ioctl_lock;
/* list of dirty qgroups to be written at next commit */
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 87355a38a654..4373da7bcc0d 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -452,46 +452,6 @@ static void btrfs_drop_pages(struct page **pages, size_t num_pages)
}
}
-static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
- const u64 start,
- const u64 len,
- struct extent_state **cached_state)
-{
- u64 search_start = start;
- const u64 end = start + len - 1;
-
- while (search_start < end) {
- const u64 search_len = end - search_start + 1;
- struct extent_map *em;
- u64 em_len;
- int ret = 0;
-
- em = btrfs_get_extent(inode, NULL, 0, search_start, search_len);
- if (IS_ERR(em))
- return PTR_ERR(em);
-
- if (em->block_start != EXTENT_MAP_HOLE)
- goto next;
-
- em_len = em->len;
- if (em->start < search_start)
- em_len -= search_start - em->start;
- if (em_len > search_len)
- em_len = search_len;
-
- ret = set_extent_bit(&inode->io_tree, search_start,
- search_start + em_len - 1,
- EXTENT_DELALLOC_NEW,
- NULL, cached_state, GFP_NOFS);
-next:
- search_start = extent_map_end(em);
- free_extent_map(em);
- if (ret)
- return ret;
- }
- return 0;
-}
-
/*
* after copy_from_user, pages need to be dirtied and we need to make
* sure holes are created between the current EOF and the start of
@@ -528,23 +488,6 @@ int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages,
EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
0, 0, cached);
- if (!btrfs_is_free_space_inode(inode)) {
- if (start_pos >= isize &&
- !(inode->flags & BTRFS_INODE_PREALLOC)) {
- /*
- * There can't be any extents following eof in this case
- * so just set the delalloc new bit for the range
- * directly.
- */
- extra_bits |= EXTENT_DELALLOC_NEW;
- } else {
- err = btrfs_find_new_delalloc_bytes(inode, start_pos,
- num_bytes, cached);
- if (err)
- return err;
- }
- }
-
err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
extra_bits, cached);
if (err)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index da58c58ef9aa..7e8d8169779d 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2253,11 +2253,69 @@ static int add_pending_csums(struct btrfs_trans_handle *trans,
return 0;
}
+static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
+ const u64 start,
+ const u64 len,
+ struct extent_state **cached_state)
+{
+ u64 search_start = start;
+ const u64 end = start + len - 1;
+
+ while (search_start < end) {
+ const u64 search_len = end - search_start + 1;
+ struct extent_map *em;
+ u64 em_len;
+ int ret = 0;
+
+ em = btrfs_get_extent(inode, NULL, 0, search_start, search_len);
+ if (IS_ERR(em))
+ return PTR_ERR(em);
+
+ if (em->block_start != EXTENT_MAP_HOLE)
+ goto next;
+
+ em_len = em->len;
+ if (em->start < search_start)
+ em_len -= search_start - em->start;
+ if (em_len > search_len)
+ em_len = search_len;
+
+ ret = set_extent_bit(&inode->io_tree, search_start,
+ search_start + em_len - 1,
+ EXTENT_DELALLOC_NEW,
+ NULL, cached_state, GFP_NOFS);
+next:
+ search_start = extent_map_end(em);
+ free_extent_map(em);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
int btrfs_set_extent_delalloc(struct btrfs_inode *inode, u64 start, u64 end,
unsigned int extra_bits,
struct extent_state **cached_state)
{
WARN_ON(PAGE_ALIGNED(end));
+
+ if (start >= i_size_read(&inode->vfs_inode) &&
+ !(inode->flags & BTRFS_INODE_PREALLOC)) {
+ /*
+ * There can't be any extents following eof in this case so just
+ * set the delalloc new bit for the range directly.
+ */
+ extra_bits |= EXTENT_DELALLOC_NEW;
+ } else {
+ int ret;
+
+ ret = btrfs_find_new_delalloc_bytes(inode, start,
+ end + 1 - start,
+ cached_state);
+ if (ret)
+ return ret;
+ }
+
return set_extent_delalloc(&inode->io_tree, start, end, extra_bits,
cached_state);
}
diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 77c54749f432..87bd37b70738 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -11,6 +11,7 @@
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/btrfs.h>
+#include <linux/sched/mm.h>
#include "ctree.h"
#include "transaction.h"
@@ -497,13 +498,13 @@ next2:
break;
}
out:
+ btrfs_free_path(path);
fs_info->qgroup_flags |= flags;
if (!(fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_ON))
clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
else if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN &&
ret >= 0)
ret = qgroup_rescan_init(fs_info, rescan_progress, 0);
- btrfs_free_path(path);
if (ret < 0) {
ulist_free(fs_info->qgroup_ulist);
@@ -936,6 +937,7 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
struct btrfs_key found_key;
struct btrfs_qgroup *qgroup = NULL;
struct btrfs_trans_handle *trans = NULL;
+ struct ulist *ulist = NULL;
int ret = 0;
int slot;
@@ -943,8 +945,8 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
if (fs_info->quota_root)
goto out;
- fs_info->qgroup_ulist = ulist_alloc(GFP_KERNEL);
- if (!fs_info->qgroup_ulist) {
+ ulist = ulist_alloc(GFP_KERNEL);
+ if (!ulist) {
ret = -ENOMEM;
goto out;
}
@@ -952,6 +954,22 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
ret = btrfs_sysfs_add_qgroups(fs_info);
if (ret < 0)
goto out;
+
+ /*
+ * Unlock qgroup_ioctl_lock before starting the transaction. This is to
+ * avoid lock acquisition inversion problems (reported by lockdep) between
+ * qgroup_ioctl_lock and the vfs freeze semaphores, acquired when we
+ * start a transaction.
+ * After we started the transaction lock qgroup_ioctl_lock again and
+ * check if someone else created the quota root in the meanwhile. If so,
+ * just return success and release the transaction handle.
+ *
+ * Also we don't need to worry about someone else calling
+ * btrfs_sysfs_add_qgroups() after we unlock and getting an error because
+ * that function returns 0 (success) when the sysfs entries already exist.
+ */
+ mutex_unlock(&fs_info->qgroup_ioctl_lock);
+
/*
* 1 for quota root item
* 1 for BTRFS_QGROUP_STATUS item
@@ -961,12 +979,20 @@ int btrfs_quota_enable(struct btrfs_fs_info *fs_info)
* would be a lot of overkill.
*/
trans = btrfs_start_transaction(tree_root, 2);
+
+ mutex_lock(&fs_info->qgroup_ioctl_lock);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
trans = NULL;
goto out;
}
+ if (fs_info->quota_root)
+ goto out;
+
+ fs_info->qgroup_ulist = ulist;
+ ulist = NULL;
+
/*
* initially create the quota tree
*/
@@ -1124,11 +1150,14 @@ out:
if (ret) {
ulist_free(fs_info->qgroup_ulist);
fs_info->qgroup_ulist = NULL;
- if (trans)
- btrfs_end_transaction(trans);
btrfs_sysfs_del_qgroups(fs_info);
}
mutex_unlock(&fs_info->qgroup_ioctl_lock);
+ if (ret && trans)
+ btrfs_end_transaction(trans);
+ else if (trans)
+ ret = btrfs_end_transaction(trans);
+ ulist_free(ulist);
return ret;
}
@@ -1141,19 +1170,29 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
mutex_lock(&fs_info->qgroup_ioctl_lock);
if (!fs_info->quota_root)
goto out;
+ mutex_unlock(&fs_info->qgroup_ioctl_lock);
/*
* 1 For the root item
*
* We should also reserve enough items for the quota tree deletion in
* btrfs_clean_quota_tree but this is not done.
+ *
+ * Also, we must always start a transaction without holding the mutex
+ * qgroup_ioctl_lock, see btrfs_quota_enable().
*/
trans = btrfs_start_transaction(fs_info->tree_root, 1);
+
+ mutex_lock(&fs_info->qgroup_ioctl_lock);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
+ trans = NULL;
goto out;
}
+ if (!fs_info->quota_root)
+ goto out;
+
clear_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags);
btrfs_qgroup_wait_for_completion(fs_info, false);
spin_lock(&fs_info->qgroup_lock);
@@ -1167,13 +1206,13 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
ret = btrfs_clean_quota_tree(trans, quota_root);
if (ret) {
btrfs_abort_transaction(trans, ret);
- goto end_trans;
+ goto out;
}
ret = btrfs_del_root(trans, &quota_root->root_key);
if (ret) {
btrfs_abort_transaction(trans, ret);
- goto end_trans;
+ goto out;
}
list_del(&quota_root->dirty_list);
@@ -1185,10 +1224,13 @@ int btrfs_quota_disable(struct btrfs_fs_info *fs_info)
btrfs_put_root(quota_root);
-end_trans:
- ret = btrfs_end_transaction(trans);
out:
mutex_unlock(&fs_info->qgroup_ioctl_lock);
+ if (ret && trans)
+ btrfs_end_transaction(trans);
+ else if (trans)
+ ret = btrfs_end_transaction(trans);
+
return ret;
}
@@ -1324,13 +1366,17 @@ int btrfs_add_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
struct btrfs_qgroup *member;
struct btrfs_qgroup_list *list;
struct ulist *tmp;
+ unsigned int nofs_flag;
int ret = 0;
/* Check the level of src and dst first */
if (btrfs_qgroup_level(src) >= btrfs_qgroup_level(dst))
return -EINVAL;
+ /* We hold a transaction handle open, must do a NOFS allocation. */
+ nofs_flag = memalloc_nofs_save();
tmp = ulist_alloc(GFP_KERNEL);
+ memalloc_nofs_restore(nofs_flag);
if (!tmp)
return -ENOMEM;
@@ -1387,10 +1433,14 @@ static int __del_qgroup_relation(struct btrfs_trans_handle *trans, u64 src,
struct btrfs_qgroup_list *list;
struct ulist *tmp;
bool found = false;
+ unsigned int nofs_flag;
int ret = 0;
int ret2;
+ /* We hold a transaction handle open, must do a NOFS allocation. */
+ nofs_flag = memalloc_nofs_save();
tmp = ulist_alloc(GFP_KERNEL);
+ memalloc_nofs_restore(nofs_flag);
if (!tmp)
return -ENOMEM;
@@ -3512,6 +3562,7 @@ static int try_flush_qgroup(struct btrfs_root *root)
{
struct btrfs_trans_handle *trans;
int ret;
+ bool can_commit = true;
/*
* We don't want to run flush again and again, so if there is a running
@@ -3523,6 +3574,20 @@ static int try_flush_qgroup(struct btrfs_root *root)
return 0;
}
+ /*
+ * If current process holds a transaction, we shouldn't flush, as we
+ * assume all space reservation happens before a transaction handle is
+ * held.
+ *
+ * But there are cases like btrfs_delayed_item_reserve_metadata() where
+ * we try to reserve space with one transction handle already held.
+ * In that case we can't commit transaction, but at least try to end it
+ * and hope the started data writes can free some space.
+ */
+ if (current->journal_info &&
+ current->journal_info != BTRFS_SEND_TRANS_STUB)
+ can_commit = false;
+
ret = btrfs_start_delalloc_snapshot(root);
if (ret < 0)
goto out;
@@ -3534,7 +3599,10 @@ static int try_flush_qgroup(struct btrfs_root *root)
goto out;
}
- ret = btrfs_commit_transaction(trans);
+ if (can_commit)
+ ret = btrfs_commit_transaction(trans);
+ else
+ ret = btrfs_end_transaction(trans);
out:
clear_bit(BTRFS_ROOT_QGROUP_FLUSHING, &root->state);
wake_up(&root->qgroup_flush_wait);
diff --git a/fs/btrfs/tests/inode-tests.c b/fs/btrfs/tests/inode-tests.c
index e6719f7db386..04022069761d 100644
--- a/fs/btrfs/tests/inode-tests.c
+++ b/fs/btrfs/tests/inode-tests.c
@@ -983,7 +983,8 @@ static int test_extent_accounting(u32 sectorsize, u32 nodesize)
ret = clear_extent_bit(&BTRFS_I(inode)->io_tree,
BTRFS_MAX_EXTENT_SIZE >> 1,
(BTRFS_MAX_EXTENT_SIZE >> 1) + sectorsize - 1,
- EXTENT_DELALLOC | EXTENT_UPTODATE, 0, 0, NULL);
+ EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
+ EXTENT_UPTODATE, 0, 0, NULL);
if (ret) {
test_err("clear_extent_bit returned %d", ret);
goto out;
@@ -1050,7 +1051,8 @@ static int test_extent_accounting(u32 sectorsize, u32 nodesize)
ret = clear_extent_bit(&BTRFS_I(inode)->io_tree,
BTRFS_MAX_EXTENT_SIZE + sectorsize,
BTRFS_MAX_EXTENT_SIZE + 2 * sectorsize - 1,
- EXTENT_DELALLOC | EXTENT_UPTODATE, 0, 0, NULL);
+ EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
+ EXTENT_UPTODATE, 0, 0, NULL);
if (ret) {
test_err("clear_extent_bit returned %d", ret);
goto out;
@@ -1082,7 +1084,8 @@ static int test_extent_accounting(u32 sectorsize, u32 nodesize)
/* Empty */
ret = clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
- EXTENT_DELALLOC | EXTENT_UPTODATE, 0, 0, NULL);
+ EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
+ EXTENT_UPTODATE, 0, 0, NULL);
if (ret) {
test_err("clear_extent_bit returned %d", ret);
goto out;
@@ -1097,7 +1100,8 @@ static int test_extent_accounting(u32 sectorsize, u32 nodesize)
out:
if (ret)
clear_extent_bit(&BTRFS_I(inode)->io_tree, 0, (u64)-1,
- EXTENT_DELALLOC | EXTENT_UPTODATE, 0, 0, NULL);
+ EXTENT_DELALLOC | EXTENT_DELALLOC_NEW |
+ EXTENT_UPTODATE, 0, 0, NULL);
iput(inode);
btrfs_free_dummy_root(root);
btrfs_free_dummy_fs_info(fs_info);
diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
index 8784b74f5232..ea2bb4cb5890 100644
--- a/fs/btrfs/tree-checker.c
+++ b/fs/btrfs/tree-checker.c
@@ -1068,6 +1068,7 @@ static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key,
"invalid root item size, have %u expect %zu or %u",
btrfs_item_size_nr(leaf, slot), sizeof(ri),
btrfs_legacy_root_item_size());
+ return -EUCLEAN;
}
/*
@@ -1423,6 +1424,7 @@ static int check_extent_data_ref(struct extent_buffer *leaf,
"invalid item size, have %u expect aligned to %zu for key type %u",
btrfs_item_size_nr(leaf, slot),
sizeof(*dref), key->type);
+ return -EUCLEAN;
}
if (!IS_ALIGNED(key->objectid, leaf->fs_info->sectorsize)) {
generic_err(leaf, slot,
@@ -1451,6 +1453,7 @@ static int check_extent_data_ref(struct extent_buffer *leaf,
extent_err(leaf, slot,
"invalid extent data backref offset, have %llu expect aligned to %u",
offset, leaf->fs_info->sectorsize);
+ return -EUCLEAN;
}
}
return 0;
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index a6406b3b8c2b..78637665166e 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -940,7 +940,13 @@ static noinline struct btrfs_device *device_list_add(const char *path,
if (device->bdev != path_bdev) {
bdput(path_bdev);
mutex_unlock(&fs_devices->device_list_mutex);
- btrfs_warn_in_rcu(device->fs_info,
+ /*
+ * device->fs_info may not be reliable here, so
+ * pass in a NULL instead. This avoids a
+ * possible use-after-free when the fs_info and
+ * fs_info->sb are already torn down.
+ */
+ btrfs_warn_in_rcu(NULL,
"duplicate device %s devid %llu generation %llu scanned by %s (%d)",
path, devid, found_transid,
current->comm,