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