The patch titled
writeback: skip new or to-be-freed inodes
has been added to the -mm tree. Its filename is
writeback-skip-new-or-to-be-freed-inodes.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: writeback: skip new or to-be-freed inodes
From: Wu Fengguang <fengguang.wu@xxxxxxxxx>
1) I_FREEING tests should be coupled with I_CLEAR
The two I_FREEING tests are racy because clear_inode() can set i_state to
I_CLEAR between the clear of I_SYNC and the test of I_FREEING.
2) skip I_WILL_FREE inodes in generic_sync_sb_inodes() to avoid possible
races with generic_forget_inode()
generic_forget_inode() sets I_WILL_FREE call writeback on its own, so
generic_sync_sb_inodes() shall not try to step in and create possible races:
generic_forget_inode
inode->i_state |= I_WILL_FREE;
spin_unlock(&inode_lock);
generic_sync_sb_inodes()
spin_lock(&inode_lock);
__iget(inode);
__writeback_single_inode
// see non zero i_count
may WARN here ==> WARN_ON(inode->i_state & I_WILL_FREE);
spin_unlock(&inode_lock);
may call generic_forget_inode again ==> iput(inode);
The above race and warning didn't turn up because writeback_inodes() holds
the s_umount lock, so generic_forget_inode() finds MS_ACTIVE and returns
early. But we are not sure the UBIFS calls and future callers will
guarantee that. So skip I_WILL_FREE inodes for the sake of safety.
Cc: Eric Sandeen <sandeen@xxxxxxxxxxx>
Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: Masayoshi MIZUMA <m.mizuma@xxxxxxxxxxxxxx>
Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Cc: Artem Bityutskiy <dedekind1@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Acked-by: Jan Kara <jack@xxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/fs-writeback.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff -puN fs/fs-writeback.c~writeback-skip-new-or-to-be-freed-inodes fs/fs-writeback.c
--- a/fs/fs-writeback.c~writeback-skip-new-or-to-be-freed-inodes
+++ a/fs/fs-writeback.c
@@ -321,7 +321,7 @@ __sync_single_inode(struct inode *inode,
spin_lock(&inode_lock);
inode->i_state &= ~I_SYNC;
- if (!(inode->i_state & I_FREEING)) {
+ if (!(inode->i_state & (I_FREEING | I_CLEAR))) {
if (!(inode->i_state & I_DIRTY) &&
mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
/*
@@ -492,7 +492,7 @@ void generic_sync_sb_inodes(struct super
break;
}
- if (inode->i_state & I_NEW) {
+ if (inode->i_state & (I_NEW | I_WILL_FREE)) {
requeue_io(inode);
continue;
}
@@ -523,7 +523,7 @@ void generic_sync_sb_inodes(struct super
if (current_is_pdflush() && !writeback_acquire(bdi))
break;
- BUG_ON(inode->i_state & I_FREEING);
+ BUG_ON(inode->i_state & (I_FREEING | I_CLEAR));
__iget(inode);
pages_skipped = wbc->pages_skipped;
__writeback_single_inode(inode, wbc);
_
Patches currently in -mm which might be from fengguang.wu@xxxxxxxxx are
linux-next.patch
readahead-make-mmap_miss-an-unsigned-int.patch
readahead-move-max_sane_readahead-calls-into-force_page_cache_readahead.patch
readahead-apply-max_sane_readahead-limit-in-ondemand_readahead.patch
readahead-remove-one-unnecessary-radix-tree-lookup.patch
readahead-increase-interleaved-readahead-size.patch
readahead-remove-sync-async-readahead-call-dependency.patch
readahead-clean-up-and-simplify-the-code-for-filemap-page-fault-readahead.patch
readahead-sequential-mmap-readahead.patch
readahead-enforce-full-readahead-size-on-async-mmap-readahead.patch
readahead-record-mmap-read-around-states-in-file_ra_state.patch
radix-tree-add-radix_tree_prev_hole.patch
readahead-move-the-random-read-case-to-bottom.patch
readahead-introduce-context-readahead-algorithm.patch
readahead-introduce-context-readahead-algorithm-update.patch
readahead-remove-redundant-test-in-shrink_readahead_size_eio.patch
readahead-enforce-full-sync-mmap-readahead-size.patch
mm-introduce-pagehuge-for-testing-huge-gigantic-pages.patch
mm-introduce-pagehuge-for-testing-huge-gigantic-pages-update.patch
proc-kpagecount-kpageflags-code-cleanup.patch
proc-export-more-page-flags-in-proc-kpageflags.patch
pagemap-document-clarifications.patch
pagemap-document-9-more-exported-page-flags.patch
pagemap-add-page-types-tool.patch
pagemap-add-page-types-tool-fix.patch
pagemap-export-pg_hwpoison.patch
pagemap-export-pg_hwpoison-fix.patch
vmscan-cleanup-the-scan-batching-code.patch
vmscan-dont-export-nr_saved_scan-in-proc-zoneinfo.patch
vmscan-zvc-updates-in-shrink_active_list-can-be-done-once.patch
readahead-add-blk_run_backing_dev.patch
readahead-add-blk_run_backing_dev-fix.patch
readahead-add-blk_run_backing_dev-fix-fix-2.patch
mm-remove-__invalidate_mapping_pages-variant.patch
vmscan-report-vm_flags-in-page_referenced.patch
vmscan-make-mapped-executable-pages-the-first-class-citizen.patch
vmscan-merge-duplicate-code-in-shrink_active_list.patch
writeback-skip-new-or-to-be-freed-inodes.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
