The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 7081929ab2572920e94d70be3d332e5c9f97095a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024012747-marshland-overcoat-1e01@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
7081929ab257 ("btrfs: don't abort filesystem when attempting to snapshot deleted subvolume")
813febdbe6c9 ("btrfs: disable snapshot creation/deletion for extent tree v2")
4467af880929 ("btrfs: remove root argument from btrfs_unlink_inode()")
bd54f381a12a ("btrfs: do not pin logs too early during renames")
9a56fcd15a9c ("btrfs: make btrfs_update_inode take btrfs_inode")
76aea5379678 ("btrfs: make btrfs_inode_safe_disk_i_size_write take btrfs_inode")
2766ff61762c ("btrfs: update the number of bytes used by an inode atomically")
5893dfb98f25 ("btrfs: refactor btrfs_drop_extents() to make it easier to extend")
ac5887c8e013 ("btrfs: locking: remove all the blocking helpers")
a14b78ad06ab ("btrfs: introduce btrfs_inode_lock()/unlock()")
b8d8e1fd570a ("btrfs: introduce btrfs_write_check()")
c86537a42f86 ("btrfs: check FS error state bit early during write")
5e8b9ef30392 ("btrfs: move pos increment and pagecache extension to btrfs_buffered_write")
4e4cabece9f9 ("btrfs: split btrfs_direct_IO to read and write")
196d59ab9ccc ("btrfs: switch extent buffer tree lock to rw_semaphore")
0425e7badbdc ("btrfs: don't fallback to buffered read if we don't need to")
3c38c877fcb9 ("btrfs: sink inode argument in insert_ordered_extent_file_extent")
fc0d82e103c7 ("btrfs: sink total_data parameter in setup_items_for_insert")
3dc9dc8969dc ("btrfs: eliminate total_size parameter from setup_items_for_insert")
0cbb5bdfea26 ("btrfs: rename btrfs_insert_clone_extent() to a more generic name")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 7081929ab2572920e94d70be3d332e5c9f97095a Mon Sep 17 00:00:00 2001
From: Omar Sandoval <osandov(a)fb.com>
Date: Thu, 4 Jan 2024 11:48:46 -0800
Subject: [PATCH] btrfs: don't abort filesystem when attempting to snapshot
deleted subvolume
If the source file descriptor to the snapshot ioctl refers to a deleted
subvolume, we get the following abort:
BTRFS: Transaction aborted (error -2)
WARNING: CPU: 0 PID: 833 at fs/btrfs/transaction.c:1875 create_pending_snapshot+0x1040/0x1190 [btrfs]
Modules linked in: pata_acpi btrfs ata_piix libata scsi_mod virtio_net blake2b_generic xor net_failover virtio_rng failover scsi_common rng_core raid6_pq libcrc32c
CPU: 0 PID: 833 Comm: t_snapshot_dele Not tainted 6.7.0-rc6 #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-1.fc39 04/01/2014
RIP: 0010:create_pending_snapshot+0x1040/0x1190 [btrfs]
RSP: 0018:ffffa09c01337af8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff9982053e7c78 RCX: 0000000000000027
RDX: ffff99827dc20848 RSI: 0000000000000001 RDI: ffff99827dc20840
RBP: ffffa09c01337c00 R08: 0000000000000000 R09: ffffa09c01337998
R10: 0000000000000003 R11: ffffffffb96da248 R12: fffffffffffffffe
R13: ffff99820535bb28 R14: ffff99820b7bd000 R15: ffff99820381ea80
FS: 00007fe20aadabc0(0000) GS:ffff99827dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000559a120b502f CR3: 00000000055b6000 CR4: 00000000000006f0
Call Trace:
<TASK>
? create_pending_snapshot+0x1040/0x1190 [btrfs]
? __warn+0x81/0x130
? create_pending_snapshot+0x1040/0x1190 [btrfs]
? report_bug+0x171/0x1a0
? handle_bug+0x3a/0x70
? exc_invalid_op+0x17/0x70
? asm_exc_invalid_op+0x1a/0x20
? create_pending_snapshot+0x1040/0x1190 [btrfs]
? create_pending_snapshot+0x1040/0x1190 [btrfs]
create_pending_snapshots+0x92/0xc0 [btrfs]
btrfs_commit_transaction+0x66b/0xf40 [btrfs]
btrfs_mksubvol+0x301/0x4d0 [btrfs]
btrfs_mksnapshot+0x80/0xb0 [btrfs]
__btrfs_ioctl_snap_create+0x1c2/0x1d0 [btrfs]
btrfs_ioctl_snap_create_v2+0xc4/0x150 [btrfs]
btrfs_ioctl+0x8a6/0x2650 [btrfs]
? kmem_cache_free+0x22/0x340
? do_sys_openat2+0x97/0xe0
__x64_sys_ioctl+0x97/0xd0
do_syscall_64+0x46/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
RIP: 0033:0x7fe20abe83af
RSP: 002b:00007ffe6eff1360 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fe20abe83af
RDX: 00007ffe6eff23c0 RSI: 0000000050009417 RDI: 0000000000000003
RBP: 0000000000000003 R08: 0000000000000000 R09: 00007fe20ad16cd0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe6eff13c0 R14: 00007fe20ad45000 R15: 0000559a120b6d58
</TASK>
---[ end trace 0000000000000000 ]---
BTRFS: error (device vdc: state A) in create_pending_snapshot:1875: errno=-2 No such entry
BTRFS info (device vdc: state EA): forced readonly
BTRFS warning (device vdc: state EA): Skipping commit of aborted transaction.
BTRFS: error (device vdc: state EA) in cleanup_transaction:2055: errno=-2 No such entry
This happens because create_pending_snapshot() initializes the new root
item as a copy of the source root item. This includes the refs field,
which is 0 for a deleted subvolume. The call to btrfs_insert_root()
therefore inserts a root with refs == 0. btrfs_get_new_fs_root() then
finds the root and returns -ENOENT if refs == 0, which causes
create_pending_snapshot() to abort.
Fix it by checking the source root's refs before attempting the
snapshot, but after locking subvol_sem to avoid racing with deletion.
CC: stable(a)vger.kernel.org # 4.14+
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Anand Jain <anand.jain(a)oracle.com>
Signed-off-by: Omar Sandoval <osandov(a)fb.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4e50b62db2a8..fea5d37528b8 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -790,6 +790,9 @@ static int create_snapshot(struct btrfs_root *root, struct inode *dir,
return -EOPNOTSUPP;
}
+ if (btrfs_root_refs(&root->root_item) == 0)
+ return -ENOENT;
+
if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))
return -EINVAL;
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-4.19.y
git checkout FETCH_HEAD
git cherry-pick -x 3324d0547861b16cf436d54abba7052e0c8aa9de
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024012738-abdomen-crimson-3018@gregkh' --subject-prefix 'PATCH 4.19.y' HEAD^..
Possible dependencies:
3324d0547861 ("btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot of subvolume being deleted")
60021bd754c6 ("btrfs: prevent subvol with swapfile from being deleted")
dd0734f2a866 ("btrfs: fix race between swap file activation and snapshot creation")
ee0d904fd9c5 ("btrfs: remove err variable from btrfs_delete_subvolume")
c3e1f96c37d0 ("btrfs: enumerate the type of exclusive operation in progress")
e85fde5162bf ("btrfs: qgroup: fix qgroup meta rsv leak for subvolume operations")
adca4d945c8d ("btrfs: qgroup: remove ASYNC_COMMIT mechanism in favor of reserve retry-after-EDQUOT")
c11fbb6ed0dd ("btrfs: reduce lock contention when creating snapshot")
63f018be577f ("btrfs: Remove __ prefix from btrfs_block_rsv_release")
dcc3eb9638c3 ("btrfs: convert snapshot/nocow exlcusion to drew lock")
0024652895e3 ("btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root")
bd647ce385ec ("btrfs: add a leak check for roots")
8260edba67a2 ("btrfs: make the init of static elements in fs_info separate")
ae18c37ad5a1 ("btrfs: move fs_info init work into it's own helper function")
141386e1a5d6 ("btrfs: free more things in btrfs_free_fs_info")
bc44d7c4b2b1 ("btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root")
81f096edf047 ("btrfs: use btrfs_put_fs_root to free roots always")
0d4b0463011d ("btrfs: export and rename free_fs_info")
fbb0ce40d606 ("btrfs: hold a ref on the root in btrfs_check_uuid_tree_entry")
ca2037fba6af ("btrfs: hold a ref on the root in btrfs_recover_log_trees")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3324d0547861b16cf436d54abba7052e0c8aa9de Mon Sep 17 00:00:00 2001
From: Omar Sandoval <osandov(a)fb.com>
Date: Thu, 4 Jan 2024 11:48:47 -0800
Subject: [PATCH] btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot
of subvolume being deleted
Sweet Tea spotted a race between subvolume deletion and snapshotting
that can result in the root item for the snapshot having the
BTRFS_ROOT_SUBVOL_DEAD flag set. The race is:
Thread 1 | Thread 2
----------------------------------------------|----------
btrfs_delete_subvolume |
btrfs_set_root_flags(BTRFS_ROOT_SUBVOL_DEAD)|
|btrfs_mksubvol
| down_read(subvol_sem)
| create_snapshot
| ...
| create_pending_snapshot
| copy root item from source
down_write(subvol_sem) |
This flag is only checked in send and swap activate, which this would
cause to fail mysteriously.
create_snapshot() now checks the root refs to reject a deleted
subvolume, so we can fix this by locking subvol_sem earlier so that the
BTRFS_ROOT_SUBVOL_DEAD flag and the root refs are updated atomically.
CC: stable(a)vger.kernel.org # 4.14+
Reported-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Anand Jain <anand.jain(a)oracle.com>
Signed-off-by: Omar Sandoval <osandov(a)fb.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b3e39610cc95..7bcc1c03437a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4458,6 +4458,8 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
u64 root_flags;
int ret;
+ down_write(&fs_info->subvol_sem);
+
/*
* Don't allow to delete a subvolume with send in progress. This is
* inside the inode lock so the error handling that has to drop the bit
@@ -4469,25 +4471,25 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
btrfs_warn(fs_info,
"attempt to delete subvolume %llu during send",
dest->root_key.objectid);
- return -EPERM;
+ ret = -EPERM;
+ goto out_up_write;
}
if (atomic_read(&dest->nr_swapfiles)) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu with active swapfile",
root->root_key.objectid);
- return -EPERM;
+ ret = -EPERM;
+ goto out_up_write;
}
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags | BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
- down_write(&fs_info->subvol_sem);
-
ret = may_destroy_subvol(dest);
if (ret)
- goto out_up_write;
+ goto out_undead;
btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
@@ -4497,7 +4499,7 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
*/
ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
if (ret)
- goto out_up_write;
+ goto out_undead;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
@@ -4563,15 +4565,17 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
inode->i_flags |= S_DEAD;
out_release:
btrfs_subvolume_release_metadata(root, &block_rsv);
-out_up_write:
- up_write(&fs_info->subvol_sem);
+out_undead:
if (ret) {
spin_lock(&dest->root_item_lock);
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
- } else {
+ }
+out_up_write:
+ up_write(&fs_info->subvol_sem);
+ if (!ret) {
d_invalidate(dentry);
btrfs_prune_dentries(dest);
ASSERT(dest->send_in_progress == 0);
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y
git checkout FETCH_HEAD
git cherry-pick -x 3324d0547861b16cf436d54abba7052e0c8aa9de
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024012736-narrow-thievish-cc02@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
3324d0547861 ("btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot of subvolume being deleted")
60021bd754c6 ("btrfs: prevent subvol with swapfile from being deleted")
dd0734f2a866 ("btrfs: fix race between swap file activation and snapshot creation")
ee0d904fd9c5 ("btrfs: remove err variable from btrfs_delete_subvolume")
c3e1f96c37d0 ("btrfs: enumerate the type of exclusive operation in progress")
e85fde5162bf ("btrfs: qgroup: fix qgroup meta rsv leak for subvolume operations")
adca4d945c8d ("btrfs: qgroup: remove ASYNC_COMMIT mechanism in favor of reserve retry-after-EDQUOT")
c11fbb6ed0dd ("btrfs: reduce lock contention when creating snapshot")
63f018be577f ("btrfs: Remove __ prefix from btrfs_block_rsv_release")
dcc3eb9638c3 ("btrfs: convert snapshot/nocow exlcusion to drew lock")
0024652895e3 ("btrfs: rename btrfs_put_fs_root and btrfs_grab_fs_root")
bd647ce385ec ("btrfs: add a leak check for roots")
8260edba67a2 ("btrfs: make the init of static elements in fs_info separate")
ae18c37ad5a1 ("btrfs: move fs_info init work into it's own helper function")
141386e1a5d6 ("btrfs: free more things in btrfs_free_fs_info")
bc44d7c4b2b1 ("btrfs: push btrfs_grab_fs_root into btrfs_get_fs_root")
81f096edf047 ("btrfs: use btrfs_put_fs_root to free roots always")
0d4b0463011d ("btrfs: export and rename free_fs_info")
fbb0ce40d606 ("btrfs: hold a ref on the root in btrfs_check_uuid_tree_entry")
ca2037fba6af ("btrfs: hold a ref on the root in btrfs_recover_log_trees")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3324d0547861b16cf436d54abba7052e0c8aa9de Mon Sep 17 00:00:00 2001
From: Omar Sandoval <osandov(a)fb.com>
Date: Thu, 4 Jan 2024 11:48:47 -0800
Subject: [PATCH] btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot
of subvolume being deleted
Sweet Tea spotted a race between subvolume deletion and snapshotting
that can result in the root item for the snapshot having the
BTRFS_ROOT_SUBVOL_DEAD flag set. The race is:
Thread 1 | Thread 2
----------------------------------------------|----------
btrfs_delete_subvolume |
btrfs_set_root_flags(BTRFS_ROOT_SUBVOL_DEAD)|
|btrfs_mksubvol
| down_read(subvol_sem)
| create_snapshot
| ...
| create_pending_snapshot
| copy root item from source
down_write(subvol_sem) |
This flag is only checked in send and swap activate, which this would
cause to fail mysteriously.
create_snapshot() now checks the root refs to reject a deleted
subvolume, so we can fix this by locking subvol_sem earlier so that the
BTRFS_ROOT_SUBVOL_DEAD flag and the root refs are updated atomically.
CC: stable(a)vger.kernel.org # 4.14+
Reported-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Anand Jain <anand.jain(a)oracle.com>
Signed-off-by: Omar Sandoval <osandov(a)fb.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b3e39610cc95..7bcc1c03437a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4458,6 +4458,8 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
u64 root_flags;
int ret;
+ down_write(&fs_info->subvol_sem);
+
/*
* Don't allow to delete a subvolume with send in progress. This is
* inside the inode lock so the error handling that has to drop the bit
@@ -4469,25 +4471,25 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
btrfs_warn(fs_info,
"attempt to delete subvolume %llu during send",
dest->root_key.objectid);
- return -EPERM;
+ ret = -EPERM;
+ goto out_up_write;
}
if (atomic_read(&dest->nr_swapfiles)) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu with active swapfile",
root->root_key.objectid);
- return -EPERM;
+ ret = -EPERM;
+ goto out_up_write;
}
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags | BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
- down_write(&fs_info->subvol_sem);
-
ret = may_destroy_subvol(dest);
if (ret)
- goto out_up_write;
+ goto out_undead;
btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
@@ -4497,7 +4499,7 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
*/
ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
if (ret)
- goto out_up_write;
+ goto out_undead;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
@@ -4563,15 +4565,17 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
inode->i_flags |= S_DEAD;
out_release:
btrfs_subvolume_release_metadata(root, &block_rsv);
-out_up_write:
- up_write(&fs_info->subvol_sem);
+out_undead:
if (ret) {
spin_lock(&dest->root_item_lock);
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
- } else {
+ }
+out_up_write:
+ up_write(&fs_info->subvol_sem);
+ if (!ret) {
d_invalidate(dentry);
btrfs_prune_dentries(dest);
ASSERT(dest->send_in_progress == 0);
The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x 3324d0547861b16cf436d54abba7052e0c8aa9de
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024012735-gentile-overture-2afa@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..
Possible dependencies:
3324d0547861 ("btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot of subvolume being deleted")
60021bd754c6 ("btrfs: prevent subvol with swapfile from being deleted")
dd0734f2a866 ("btrfs: fix race between swap file activation and snapshot creation")
ee0d904fd9c5 ("btrfs: remove err variable from btrfs_delete_subvolume")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3324d0547861b16cf436d54abba7052e0c8aa9de Mon Sep 17 00:00:00 2001
From: Omar Sandoval <osandov(a)fb.com>
Date: Thu, 4 Jan 2024 11:48:47 -0800
Subject: [PATCH] btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot
of subvolume being deleted
Sweet Tea spotted a race between subvolume deletion and snapshotting
that can result in the root item for the snapshot having the
BTRFS_ROOT_SUBVOL_DEAD flag set. The race is:
Thread 1 | Thread 2
----------------------------------------------|----------
btrfs_delete_subvolume |
btrfs_set_root_flags(BTRFS_ROOT_SUBVOL_DEAD)|
|btrfs_mksubvol
| down_read(subvol_sem)
| create_snapshot
| ...
| create_pending_snapshot
| copy root item from source
down_write(subvol_sem) |
This flag is only checked in send and swap activate, which this would
cause to fail mysteriously.
create_snapshot() now checks the root refs to reject a deleted
subvolume, so we can fix this by locking subvol_sem earlier so that the
BTRFS_ROOT_SUBVOL_DEAD flag and the root refs are updated atomically.
CC: stable(a)vger.kernel.org # 4.14+
Reported-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Anand Jain <anand.jain(a)oracle.com>
Signed-off-by: Omar Sandoval <osandov(a)fb.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b3e39610cc95..7bcc1c03437a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4458,6 +4458,8 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
u64 root_flags;
int ret;
+ down_write(&fs_info->subvol_sem);
+
/*
* Don't allow to delete a subvolume with send in progress. This is
* inside the inode lock so the error handling that has to drop the bit
@@ -4469,25 +4471,25 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
btrfs_warn(fs_info,
"attempt to delete subvolume %llu during send",
dest->root_key.objectid);
- return -EPERM;
+ ret = -EPERM;
+ goto out_up_write;
}
if (atomic_read(&dest->nr_swapfiles)) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu with active swapfile",
root->root_key.objectid);
- return -EPERM;
+ ret = -EPERM;
+ goto out_up_write;
}
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags | BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
- down_write(&fs_info->subvol_sem);
-
ret = may_destroy_subvol(dest);
if (ret)
- goto out_up_write;
+ goto out_undead;
btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
@@ -4497,7 +4499,7 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
*/
ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
if (ret)
- goto out_up_write;
+ goto out_undead;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
@@ -4563,15 +4565,17 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
inode->i_flags |= S_DEAD;
out_release:
btrfs_subvolume_release_metadata(root, &block_rsv);
-out_up_write:
- up_write(&fs_info->subvol_sem);
+out_undead:
if (ret) {
spin_lock(&dest->root_item_lock);
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
- } else {
+ }
+out_up_write:
+ up_write(&fs_info->subvol_sem);
+ if (!ret) {
d_invalidate(dentry);
btrfs_prune_dentries(dest);
ASSERT(dest->send_in_progress == 0);
The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 3324d0547861b16cf436d54abba7052e0c8aa9de
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024012733-expert-landlady-ce9c@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..
Possible dependencies:
3324d0547861 ("btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot of subvolume being deleted")
60021bd754c6 ("btrfs: prevent subvol with swapfile from being deleted")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3324d0547861b16cf436d54abba7052e0c8aa9de Mon Sep 17 00:00:00 2001
From: Omar Sandoval <osandov(a)fb.com>
Date: Thu, 4 Jan 2024 11:48:47 -0800
Subject: [PATCH] btrfs: avoid copying BTRFS_ROOT_SUBVOL_DEAD flag to snapshot
of subvolume being deleted
Sweet Tea spotted a race between subvolume deletion and snapshotting
that can result in the root item for the snapshot having the
BTRFS_ROOT_SUBVOL_DEAD flag set. The race is:
Thread 1 | Thread 2
----------------------------------------------|----------
btrfs_delete_subvolume |
btrfs_set_root_flags(BTRFS_ROOT_SUBVOL_DEAD)|
|btrfs_mksubvol
| down_read(subvol_sem)
| create_snapshot
| ...
| create_pending_snapshot
| copy root item from source
down_write(subvol_sem) |
This flag is only checked in send and swap activate, which this would
cause to fail mysteriously.
create_snapshot() now checks the root refs to reject a deleted
subvolume, so we can fix this by locking subvol_sem earlier so that the
BTRFS_ROOT_SUBVOL_DEAD flag and the root refs are updated atomically.
CC: stable(a)vger.kernel.org # 4.14+
Reported-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Sweet Tea Dorminy <sweettea-kernel(a)dorminy.me>
Reviewed-by: Anand Jain <anand.jain(a)oracle.com>
Signed-off-by: Omar Sandoval <osandov(a)fb.com>
Reviewed-by: David Sterba <dsterba(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index b3e39610cc95..7bcc1c03437a 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4458,6 +4458,8 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
u64 root_flags;
int ret;
+ down_write(&fs_info->subvol_sem);
+
/*
* Don't allow to delete a subvolume with send in progress. This is
* inside the inode lock so the error handling that has to drop the bit
@@ -4469,25 +4471,25 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
btrfs_warn(fs_info,
"attempt to delete subvolume %llu during send",
dest->root_key.objectid);
- return -EPERM;
+ ret = -EPERM;
+ goto out_up_write;
}
if (atomic_read(&dest->nr_swapfiles)) {
spin_unlock(&dest->root_item_lock);
btrfs_warn(fs_info,
"attempt to delete subvolume %llu with active swapfile",
root->root_key.objectid);
- return -EPERM;
+ ret = -EPERM;
+ goto out_up_write;
}
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags | BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
- down_write(&fs_info->subvol_sem);
-
ret = may_destroy_subvol(dest);
if (ret)
- goto out_up_write;
+ goto out_undead;
btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
/*
@@ -4497,7 +4499,7 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
*/
ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 5, true);
if (ret)
- goto out_up_write;
+ goto out_undead;
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
@@ -4563,15 +4565,17 @@ int btrfs_delete_subvolume(struct btrfs_inode *dir, struct dentry *dentry)
inode->i_flags |= S_DEAD;
out_release:
btrfs_subvolume_release_metadata(root, &block_rsv);
-out_up_write:
- up_write(&fs_info->subvol_sem);
+out_undead:
if (ret) {
spin_lock(&dest->root_item_lock);
root_flags = btrfs_root_flags(&dest->root_item);
btrfs_set_root_flags(&dest->root_item,
root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
spin_unlock(&dest->root_item_lock);
- } else {
+ }
+out_up_write:
+ up_write(&fs_info->subvol_sem);
+ if (!ret) {
d_invalidate(dentry);
btrfs_prune_dentries(dest);
ASSERT(dest->send_in_progress == 0);
The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x f546c4282673497a06ecb6190b50ae7f6c85b02f
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024012740-mating-boxing-dd93@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..
Possible dependencies:
f546c4282673 ("btrfs: scrub: avoid use-after-free when chunk length is not 64K aligned")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f546c4282673497a06ecb6190b50ae7f6c85b02f Mon Sep 17 00:00:00 2001
From: Qu Wenruo <wqu(a)suse.com>
Date: Wed, 17 Jan 2024 11:02:25 +1030
Subject: [PATCH] btrfs: scrub: avoid use-after-free when chunk length is not
64K aligned
[BUG]
There is a bug report that, on a ext4-converted btrfs, scrub leads to
various problems, including:
- "unable to find chunk map" errors
BTRFS info (device vdb): scrub: started on devid 1
BTRFS critical (device vdb): unable to find chunk map for logical 2214744064 length 4096
BTRFS critical (device vdb): unable to find chunk map for logical 2214744064 length 45056
This would lead to unrepariable errors.
- Use-after-free KASAN reports:
==================================================================
BUG: KASAN: slab-use-after-free in __blk_rq_map_sg+0x18f/0x7c0
Read of size 8 at addr ffff8881013c9040 by task btrfs/909
CPU: 0 PID: 909 Comm: btrfs Not tainted 6.7.0-x64v3-dbg #11 c50636e9419a8354555555245df535e380563b2b
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 2023.11-2 12/24/2023
Call Trace:
<TASK>
dump_stack_lvl+0x43/0x60
print_report+0xcf/0x640
kasan_report+0xa6/0xd0
__blk_rq_map_sg+0x18f/0x7c0
virtblk_prep_rq.isra.0+0x215/0x6a0 [virtio_blk 19a65eeee9ae6fcf02edfad39bb9ddee07dcdaff]
virtio_queue_rqs+0xc4/0x310 [virtio_blk 19a65eeee9ae6fcf02edfad39bb9ddee07dcdaff]
blk_mq_flush_plug_list.part.0+0x780/0x860
__blk_flush_plug+0x1ba/0x220
blk_finish_plug+0x3b/0x60
submit_initial_group_read+0x10a/0x290 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
flush_scrub_stripes+0x38e/0x430 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
scrub_stripe+0x82a/0xae0 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
scrub_chunk+0x178/0x200 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
scrub_enumerate_chunks+0x4bc/0xa30 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
btrfs_scrub_dev+0x398/0x810 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
btrfs_ioctl+0x4b9/0x3020 [btrfs e57987a360bed82fe8756dcd3e0de5406ccfe965]
__x64_sys_ioctl+0xbd/0x100
do_syscall_64+0x5d/0xe0
entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f47e5e0952b
- Crash, mostly due to above use-after-free
[CAUSE]
The converted fs has the following data chunk layout:
item 2 key (FIRST_CHUNK_TREE CHUNK_ITEM 2214658048) itemoff 16025 itemsize 80
length 86016 owner 2 stripe_len 65536 type DATA|single
For above logical bytenr 2214744064, it's at the chunk end
(2214658048 + 86016 = 2214744064).
This means btrfs_submit_bio() would split the bio, and trigger endio
function for both of the two halves.
However scrub_submit_initial_read() would only expect the endio function
to be called once, not any more.
This means the first endio function would already free the bbio::bio,
leaving the bvec freed, thus the 2nd endio call would lead to
use-after-free.
[FIX]
- Make sure scrub_read_endio() only updates bits in its range
Since we may read less than 64K at the end of the chunk, we should not
touch the bits beyond chunk boundary.
- Make sure scrub_submit_initial_read() only to read the chunk range
This is done by calculating the real number of sectors we need to
read, and add sector-by-sector to the bio.
Thankfully the scrub read repair path won't need extra fixes:
- scrub_stripe_submit_repair_read()
With above fixes, we won't update error bit for range beyond chunk,
thus scrub_stripe_submit_repair_read() should never submit any read
beyond the chunk.
Reported-by: Rongrong <i(a)rong.moe>
Fixes: e02ee89baa66 ("btrfs: scrub: switch scrub_simple_mirror() to scrub_stripe infrastructure")
Tested-by: Rongrong <i(a)rong.moe>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn(a)wdc.com>
Signed-off-by: Qu Wenruo <wqu(a)suse.com>
Signed-off-by: David Sterba <dsterba(a)suse.com>
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index a01807cbd4d4..2d81b1a18a04 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1098,12 +1098,22 @@ static void scrub_stripe_read_repair_worker(struct work_struct *work)
static void scrub_read_endio(struct btrfs_bio *bbio)
{
struct scrub_stripe *stripe = bbio->private;
+ struct bio_vec *bvec;
+ int sector_nr = calc_sector_number(stripe, bio_first_bvec_all(&bbio->bio));
+ int num_sectors;
+ u32 bio_size = 0;
+ int i;
+
+ ASSERT(sector_nr < stripe->nr_sectors);
+ bio_for_each_bvec_all(bvec, &bbio->bio, i)
+ bio_size += bvec->bv_len;
+ num_sectors = bio_size >> stripe->bg->fs_info->sectorsize_bits;
if (bbio->bio.bi_status) {
- bitmap_set(&stripe->io_error_bitmap, 0, stripe->nr_sectors);
- bitmap_set(&stripe->error_bitmap, 0, stripe->nr_sectors);
+ bitmap_set(&stripe->io_error_bitmap, sector_nr, num_sectors);
+ bitmap_set(&stripe->error_bitmap, sector_nr, num_sectors);
} else {
- bitmap_clear(&stripe->io_error_bitmap, 0, stripe->nr_sectors);
+ bitmap_clear(&stripe->io_error_bitmap, sector_nr, num_sectors);
}
bio_put(&bbio->bio);
if (atomic_dec_and_test(&stripe->pending_io)) {
@@ -1701,6 +1711,9 @@ static void scrub_submit_initial_read(struct scrub_ctx *sctx,
{
struct btrfs_fs_info *fs_info = sctx->fs_info;
struct btrfs_bio *bbio;
+ unsigned int nr_sectors = min(BTRFS_STRIPE_LEN, stripe->bg->start +
+ stripe->bg->length - stripe->logical) >>
+ fs_info->sectorsize_bits;
int mirror = stripe->mirror_num;
ASSERT(stripe->bg);
@@ -1715,14 +1728,16 @@ static void scrub_submit_initial_read(struct scrub_ctx *sctx,
bbio = btrfs_bio_alloc(SCRUB_STRIPE_PAGES, REQ_OP_READ, fs_info,
scrub_read_endio, stripe);
- /* Read the whole stripe. */
bbio->bio.bi_iter.bi_sector = stripe->logical >> SECTOR_SHIFT;
- for (int i = 0; i < BTRFS_STRIPE_LEN >> PAGE_SHIFT; i++) {
+ /* Read the whole range inside the chunk boundary. */
+ for (unsigned int cur = 0; cur < nr_sectors; cur++) {
+ struct page *page = scrub_stripe_get_page(stripe, cur);
+ unsigned int pgoff = scrub_stripe_get_page_offset(stripe, cur);
int ret;
- ret = bio_add_page(&bbio->bio, stripe->pages[i], PAGE_SIZE, 0);
+ ret = bio_add_page(&bbio->bio, page, fs_info->sectorsize, pgoff);
/* We should have allocated enough bio vectors. */
- ASSERT(ret == PAGE_SIZE);
+ ASSERT(ret == fs_info->sectorsize);
}
atomic_inc(&stripe->pending_io);
From: Filipe Manana <fdmanana(a)suse.com>
Here follows the backport of some directory related fixes for the stable
6.1 tree. I tested these on top of 6.1.75.
These were recently requested by a user for 5.15 stable:
https://lore.kernel.org/linux-btrfs/20240124225522.GA2614102@lxhi-087/
This request is to backport the same patches to 6.1, while the request
for 5.15 stabe is at:
https://lore.kernel.org/linux-btrfs/cover.1706183427.git.fdmanana@suse.com/
Filipe Manana (4):
btrfs: fix infinite directory reads
btrfs: set last dir index to the current last index when opening dir
btrfs: refresh dir last index during a rewinddir(3) call
btrfs: fix race between reading a directory and adding entries to it
fs/btrfs/ctree.h | 1 +
fs/btrfs/delayed-inode.c | 5 +-
fs/btrfs/delayed-inode.h | 1 +
fs/btrfs/inode.c | 150 +++++++++++++++++++++++++--------------
4 files changed, 102 insertions(+), 55 deletions(-)
--
2.40.1
Hi all,
This series resolves two independent but related issues that were
recently exposed by two LLVM changes.
https://github.com/llvm/llvm-project/commit/ec92d74a0ef89b9dd46aee6ec8aca6b…
exposes that '-no-pie' is not getting added to the linker flags with
clang, resulting in building objects with '-fno-PIE' that are linked
with '-pie', to which the linker rightfully errors with:
/usr/sbin/ld: init/main.o: relocation R_X86_64_32 against symbol `saved_command_line' can not be used when making a PIE object; recompile with -fPIE
/usr/sbin/ld: failed to set dynamic section sizes: bad value
https://github.com/llvm/llvm-project/commit/4bf8a688956a759b7b6b8d94f42d25c…
adds '.ltext' (and '.ltext.*' with '-ffunction-sections') when using
'-mcmodel=large' (which UML does), which causes a segmentation fault
with modpost.
I have tested these patches with all supported versions of clang,
noticing no regressions.
---
Nathan Chancellor (2):
um: Fix adding '-no-pie' for clang
modpost: Add '.ltext' and '.ltext.*' to TEXT_SECTIONS
arch/um/Makefile | 4 +++-
scripts/mod/modpost.c | 3 ++-
2 files changed, 5 insertions(+), 2 deletions(-)
---
base-commit: 0dd3ee31125508cd67f7e7172247f05b7fd1753a
change-id: 20240118-fix-uml-clang-18-e365b0503a29
Best regards,
--
Nathan Chancellor <nathan(a)kernel.org>
The cleanup can be dispatched while the atomic update is still active,
which means that the memory acquired in the atomic update needs to
not be invalidated by the cleanup. The buffer objects in vmw_plane_state
instead of using the builtin map_and_cache were trying to handle
the lifetime of the mapped memory themselves, leading to crashes.
Use the map_and_cache instead of trying to manage the lifetime of the
buffer objects held by the vmw_plane_state.
Fixes kernel oops'es in IGT's kms_cursor_legacy forked-bo.
Signed-off-by: Zack Rusin <zack.rusin(a)broadcom.com>
Fixes: bb6780aa5a1d ("drm/vmwgfx: Diff cursors when using cmds")
Cc: <stable(a)vger.kernel.org> # v6.2+
---
drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 13 +------------
1 file changed, 1 insertion(+), 12 deletions(-)
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
index e2bfaf4522a6..cd4925346ed4 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -185,13 +185,12 @@ static u32 vmw_du_cursor_mob_size(u32 w, u32 h)
*/
static u32 *vmw_du_cursor_plane_acquire_image(struct vmw_plane_state *vps)
{
- bool is_iomem;
if (vps->surf) {
if (vps->surf_mapped)
return vmw_bo_map_and_cache(vps->surf->res.guest_memory_bo);
return vps->surf->snooper.image;
} else if (vps->bo)
- return ttm_kmap_obj_virtual(&vps->bo->map, &is_iomem);
+ return vmw_bo_map_and_cache(vps->bo);
return NULL;
}
@@ -653,22 +652,12 @@ vmw_du_cursor_plane_cleanup_fb(struct drm_plane *plane,
{
struct vmw_cursor_plane *vcp = vmw_plane_to_vcp(plane);
struct vmw_plane_state *vps = vmw_plane_state_to_vps(old_state);
- bool is_iomem;
if (vps->surf_mapped) {
vmw_bo_unmap(vps->surf->res.guest_memory_bo);
vps->surf_mapped = false;
}
- if (vps->bo && ttm_kmap_obj_virtual(&vps->bo->map, &is_iomem)) {
- const int ret = ttm_bo_reserve(&vps->bo->tbo, true, false, NULL);
-
- if (likely(ret == 0)) {
- ttm_bo_kunmap(&vps->bo->map);
- ttm_bo_unreserve(&vps->bo->tbo);
- }
- }
-
vmw_du_cursor_plane_unmap_cm(vps);
vmw_du_put_cursor_mob(vcp, vps);
--
2.40.1