| Message ID | 20180625170341.101319-1-clm@fb.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Jun 25, 2018 at 10:03:41AM -0700, Chris Mason wrote: > The vm_fault_t conversion commit introduced a ret2 variable for tracking > the integer return values from internal btrfs functions. It was > sometimes returning VM_FAULT_LOCKED for pages that were actually invalid > and had been removed from the radix. Something like this: > > ret2 = btrfs_delalloc_reserve_space() // returns zero on success > > lock_page(page) > if (page->mapping != inode->i_mapping) > goto out_unlock; > > ... > > out_unlock: > if (!ret2) { > ... > return VM_FAULT_LOCKED; > } > > This ends up triggering this WARNING in btrfs_destroy_inode() > WARN_ON(BTRFS_I(inode)->block_rsv.size); > > xfstests generic/095 was able to reliably reproduce the errors. > > Since out_unlock: is only used for errors, this fix moves it below the > if (!ret2) check we use to return VM_FAULT_LOCKED for success. > > Fixes: a528a2415087 (btrfs: change return type of btrfs_page_mkwrite to vm_fault_t) > Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> also passed the tests here standalone and with the fixup worker fixes. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 193f933..63f713a 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9036,13 +9036,14 @@ vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) unlock_extent_cached(io_tree, page_start, page_end, &cached_state); -out_unlock: if (!ret2) { btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, true); sb_end_pagefault(inode->i_sb); extent_changeset_free(data_reserved); return VM_FAULT_LOCKED; } + +out_unlock: unlock_page(page); out: btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE, (ret != 0));
The vm_fault_t conversion commit introduced a ret2 variable for tracking the integer return values from internal btrfs functions. It was sometimes returning VM_FAULT_LOCKED for pages that were actually invalid and had been removed from the radix. Something like this: ret2 = btrfs_delalloc_reserve_space() // returns zero on success lock_page(page) if (page->mapping != inode->i_mapping) goto out_unlock; ... out_unlock: if (!ret2) { ... return VM_FAULT_LOCKED; } This ends up triggering this WARNING in btrfs_destroy_inode() WARN_ON(BTRFS_I(inode)->block_rsv.size); xfstests generic/095 was able to reliably reproduce the errors. Since out_unlock: is only used for errors, this fix moves it below the if (!ret2) check we use to return VM_FAULT_LOCKED for success. Fixes: a528a2415087 (btrfs: change return type of btrfs_page_mkwrite to vm_fault_t) Signed-off-by: Chris Mason <clm@fb.com> --- Changes since v1: don't set the vmfault_t 'ret' to zero, just move our goto taret around around instead. fs/btrfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)