Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
XArray: Do not return sibling entries from xa_load()
commit cbc0285 upstream. It is possible for xa_load() to observe a sibling entry pointing to another sibling entry. An example: Thread A: Thread B: xa_store_range(xa, entry, 188, 191, gfp); xa_load(xa, 191); entry = xa_entry(xa, node, 63); [entry is a sibling of 188] xa_store_range(xa, entry, 184, 191, gfp); if (xa_is_sibling(entry)) offset = xa_to_sibling(entry); entry = xa_entry(xas->xa, node, offset); [entry is now a sibling of 184] It is sufficient to go around this loop until we hit a non-sibling entry. Sibling entries always point earlier in the node, so we are guaranteed to terminate this search. Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Fixes: 6b24ca4 ("mm: Use multi-index entries in the page cache") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
- Loading branch information
Showing
2 changed files
with
67 additions
and
3 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters