btrfs: fix relocation crash due to premature return from btrfs_commit_transaction()

In the Linux kernel, the following vulnerability has been resolved:

btrfs: fix relocation crash due to premature return from btrfs_commit_transaction()

We are seeing crashes similar to the following trace:

[38.969182] WARNING: CPU: 20 PID: 2105 at fs/btrfs/relocation.c:4070 btrfs_relocate_block_group+0x2dc/0x340 [btrfs]

[38.973556] CPU: 20 PID: 2105 Comm: btrfs Not tainted 5.17.0-rc4 #54

[38.974580] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014

[38.976539] RIP: 0010:btrfs_relocate_block_group+0x2dc/0x340 [btrfs]

[38.980336] RSP: 0000:ffffb0dd42e03c20 EFLAGS: 00010206

[38.981218] RAX: ffff96cfc4ede800 RBX: ffff96cfc3ce0000 RCX: 000000000002ca14

[38.982560] RDX: 0000000000000000 RSI: 4cfd109a0bcb5d7f RDI: ffff96cfc3ce0360

[38.983619] RBP: ffff96cfc309c000 R08: 0000000000000000 R09: 0000000000000000

[38.984678] R10: ffff96cec0000001 R11: ffffe84c80000000 R12: ffff96cfc4ede800

[38.985735] R13: 0000000000000000 R14: 0000000000000000 R15: ffff96cfc3ce0360

[38.987146] FS: 00007f11c15218c0(0000) GS:ffff96d6dfb00000(0000) knlGS:0000000000000000

[38.988662] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

[38.989398] CR2: 00007ffc922c8e60 CR3: 00000001147a6001 CR4: 0000000000370ee0

[38.990279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000

[38.991219] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

[38.992528] Call Trace:

[38.992854] <TASK>

[38.993148] btrfs_relocate_chunk+0x27/0xe0 [btrfs]

[38.993941] btrfs_balance+0x78e/0xea0 [btrfs]

[38.994801] ? vsnprintf+0x33c/0x520

[38.995368] ? __kmalloc_track_caller+0x351/0x440

[38.996198] btrfs_ioctl_balance+0x2b9/0x3a0 [btrfs]

[38.997084] btrfs_ioctl+0x11b0/0x2da0 [btrfs]

[38.997867] ? mod_objcg_state+0xee/0x340

[38.998552] ? seq_release+0x24/0x30

[38.999184] ? proc_nr_files+0x30/0x30

[38.999654] ? call_rcu+0xc8/0x2f0

[39.000228] ? __x64_sys_ioctl+0x84/0xc0

[39.000872] ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]

[39.001973] __x64_sys_ioctl+0x84/0xc0

[39.002566] do_syscall_64+0x3a/0x80

[39.003011] entry_SYSCALL_64_after_hwframe+0x44/0xae

[39.003735] RIP: 0033:0x7f11c166959b

[39.007324] RSP: 002b:00007fff2543e998 EFLAGS: 00000246 ORIG_RAX: 0000000000000010

[39.008521] RAX: ffffffffffffffda RBX: 00007f11c1521698 RCX: 00007f11c166959b

[39.009833] RDX: 00007fff2543ea40 RSI: 00000000c4009420 RDI: 0000000000000003

[39.011270] RBP: 0000000000000003 R08: 0000000000000013 R09: 00007f11c16f94e0

[39.012581] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff25440df3

[39.014046] R13: 0000000000000000 R14: 00007fff2543ea40 R15: 0000000000000001

[39.015040] </TASK>

[39.015418] ---[ end trace 0000000000000000 ]---

[43.131559] ------------[ cut here ]------------

[43.132234] kernel BUG at fs/btrfs/extent-tree.c:2717!

[43.133031] invalid opcode: 0000 [#1] PREEMPT SMP PTI

[43.133702] CPU: 1 PID: 1839 Comm: btrfs Tainted: G W 5.17.0-rc4 #54

[43.134863] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014

[43.136426] RIP: 0010:unpin_extent_range+0x37a/0x4f0 [btrfs]

[43.139913] RSP: 0000:ffffb0dd4216bc70 EFLAGS: 00010246

[43.140629] RAX: 0000000000000000 RBX: ffff96cfc34490f8 RCX: 0000000000000001

[43.141604] RDX: 0000000080000001 RSI: 0000000051d00000 RDI: 00000000ffffffff

[43.142645] RBP: 0000000000000000 R08: 0000000000000000 R09: ffff96cfd07dca50

[43.143669] R10: ffff96cfc46e8a00 R11: fffffffffffec000 R12: 0000000041d00000

[43.144657] R13: ffff96cfc3ce0000 R14: ffffb0dd4216bd08 R15: 0000000000000000

[43.145686] FS: 00007f7657dd68c0(0000) GS:ffff96d6df640000(0000) knlGS:0000000000000000

[43.146808] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

[43.147584] CR2: 00007f7fe81bf5b0 CR3: 00000001093ee004 CR4: 0000000000370ee0

[43.148589] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000

[43.149581] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 00000000000

---truncated---