Messages in this thread | | | Date | Thu, 27 Nov 2014 14:53:47 +1100 | From | Stephen Rothwell <> | Subject | linux-next: manual merge of the block tree with the ext4 tree |
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Hi Jens,
Today's linux-next merge of the block tree got a conflict in fs/fs-writeback.c between commit ef7fdf5e8c87 ("vfs: add support for a lazytime mount option") from the ext4 tree and commit 9c6ac78eb352 ("writeback: fix a subtle race condition in I_DIRTY clearing") from the block tree.
I fixed it up (I took a guess, plese check - see below) and can carry the fix as necessary (no action is required).
-- Cheers, Stephen Rothwell sfr@canb.auug.org.au
diff --cc fs/fs-writeback.c index 3d87174408ae,2d609a5fbfea..000000000000 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@@ -482,14 -479,30 +482,30 @@@ __writeback_single_inode(struct inode * * write_inode() */ spin_lock(&inode->i_lock); - /* Clear I_DIRTY_PAGES if we've written out all dirty pages */ - if (!mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) - inode->i_state &= ~I_DIRTY_PAGES; + - dirty = inode->i_state & I_DIRTY; - inode->i_state &= ~I_DIRTY; + dirty = inode->i_state & I_DIRTY_INODE; + inode->i_state &= ~I_DIRTY_INODE; + + /* + * Paired with smp_mb() in __mark_inode_dirty(). This allows + * __mark_inode_dirty() to test i_state without grabbing i_lock - + * either they see the I_DIRTY bits cleared or we see the dirtied + * inode. + * + * I_DIRTY_PAGES is always cleared together above even if @mapping + * still has dirty pages. The flag is reinstated after smp_mb() if + * necessary. This guarantees that either __mark_inode_dirty() + * sees clear I_DIRTY_PAGES or we see PAGECACHE_TAG_DIRTY. + */ + smp_mb(); + + if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) + inode->i_state |= I_DIRTY_PAGES; + spin_unlock(&inode->i_lock); + /* Don't write the inode if only I_DIRTY_PAGES was set */ - if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) { + if (dirty) { int err = write_inode(inode, wbc); if (ret == 0) ret = err; [unhandled content-type:application/pgp-signature] | |