locking problems: Btrfs: be more selective in the defrag ioctl
From: Dan Carpenter
Date: Sat Mar 20 2010 - 07:39:09 EST
Hi Chris,
There is a locking problem in
940100a4a7b78 "Btrfs: be more selective in the defrag ioctl"
There are two places where we break out of the while loop under the
lock.
fs/btrfs/ioctl.c +708 btrfs_defrag_file(159) error: double lock 'mutex:&inode->i_mutex'
600 mutex_lock(&inode->i_mutex);
601 if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)
602 BTRFS_I(inode)->force_compress = 1;
603
604 ret = btrfs_check_data_free_space(root, inode, PAGE_CACHE_SIZE);
605 if (ret) {
606 ret = -ENOSPC;
607 break;
Here.
608 }
609
610 ret = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
611 if (ret) {
612 btrfs_free_reserved_data_space(root, inode,
613 PAGE_CACHE_SIZE);
614 ret = -ENOSPC;
615 break;
And here.
616 }
Maybe we should have "goto err_reservations;" instead of break? I
don't know the code well enough to say.
regards,
dan carpenter
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