6.12-stable review patch. If anyone has any objections, please let me know.
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From: Filipe Manana fdmanana@suse.com
[ Upstream commit 9a45022a0efadd99bcc58f7f1cc2b6fb3b808c40 ]
During swap activation we iterate over the extents of a file, then do several checks for each extent, some of which may take some significant time such as checking if an extent is shared. Since a file can have many thousands of extents, this can be a very slow operation and it's currently not interruptible. I had a bug during development of a previous patch that resulted in an infinite loop when iterating the extents, so a core was busy looping and I couldn't cancel the operation, which is very annoying and requires a reboot. So make the loop interruptible by checking for fatal signals at the end of each iteration and stopping immediately if there is one.
CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Qu Wenruo wqu@suse.com Signed-off-by: Filipe Manana fdmanana@suse.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/inode.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 4b3e256e0d0b..b5cfb85af937 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -10056,6 +10056,11 @@ static int btrfs_swap_activate(struct swap_info_struct *sis, struct file *file, bsi.block_start = physical_block_start; bsi.block_len = len; } + + if (fatal_signal_pending(current)) { + ret = -EINTR; + goto out; + } }
if (bsi.block_len)