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author | Scott Wood <scottwood@freescale.com> | 2015-02-13 22:12:06 (GMT) |
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committer | Scott Wood <scottwood@freescale.com> | 2015-02-13 22:19:22 (GMT) |
commit | 6faa2909871d8937cb2f79a10e1b21ffe193fac1 (patch) | |
tree | f558a94f1553814cc122ab8d9e04c0ebad5262a5 /fs/fs-writeback.c | |
parent | fcb2fb84301c673ee15ca04e7a2fc965712d49a0 (diff) | |
download | linux-fsl-qoriq-6faa2909871d8937cb2f79a10e1b21ffe193fac1.tar.xz |
Reset to 3.12.37
Diffstat (limited to 'fs/fs-writeback.c')
-rw-r--r-- | fs/fs-writeback.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index 5bbec31..a1b2062 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -475,12 +475,28 @@ __writeback_single_inode(struct inode *inode, struct writeback_control *wbc) * 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_SYNC | I_DIRTY_DATASYNC); + inode->i_state &= ~I_DIRTY; + + /* + * 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)) { int err = write_inode(inode, wbc); @@ -1144,12 +1160,11 @@ void __mark_inode_dirty(struct inode *inode, int flags) } /* - * make sure that changes are seen by all cpus before we test i_state - * -- mikulas + * Paired with smp_mb() in __writeback_single_inode() for the + * following lockless i_state test. See there for details. */ smp_mb(); - /* avoid the locking if we can */ if ((inode->i_state & flags) == flags) return; |