[Devel] [PATCH rh7] fs/cleancache: fix data invalidation in the cleancache during direct_io
Andrey Ryabinin
aryabinin at virtuozzo.com
Tue Apr 11 08:43:33 PDT 2017
Currently some direct_io fs hooks call invalidate_inode_pages2_range()
conditionally iff mapping->nrpages is not zero. So if nrpages is zero,
data in cleancache wouldn't be invalidated. So the next buffered read
may get stale data from the cleancache.
Fix this by calling invalidate_inode_pages2_range() regardless of nrpages
value. And if nrpages is zero, bail out from invalidate_inode_pages2_range()
only after cleancache_invalidate_inode(), so that we invalidate cleancache
but still avoid pointless page cache lookups.
https://jira.sw.ru/browse/PSBM-63908
Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
fs/9p/vfs_file.c | 4 ++--
fs/nfs/direct.c | 16 ++++++----------
fs/nfs/inode.c | 7 ++++---
fs/xfs/xfs_file.c | 16 ++++++++--------
mm/filemap.c | 28 ++++++++++++----------------
mm/truncate.c | 4 ++++
6 files changed, 36 insertions(+), 39 deletions(-)
diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 7da03f8..afe0036 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -482,7 +482,7 @@ v9fs_file_write_internal(struct inode *inode, struct p9_fid *fid,
if (invalidate && (total > 0)) {
pg_start = origin >> PAGE_CACHE_SHIFT;
pg_end = (origin + total - 1) >> PAGE_CACHE_SHIFT;
- if (inode->i_mapping && inode->i_mapping->nrpages)
+ if (inode->i_mapping)
invalidate_inode_pages2_range(inode->i_mapping,
pg_start, pg_end);
*offset += total;
@@ -688,7 +688,7 @@ v9fs_direct_write(struct file *filp, const char __user * data,
* about to write. We do this *before* the write so that if we fail
* here we fall back to buffered write
*/
- if (mapping->nrpages) {
+ {
pgoff_t pg_start = offset >> PAGE_CACHE_SHIFT;
pgoff_t pg_end = (offset + count - 1) >> PAGE_CACHE_SHIFT;
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index ab96f01..9bbbb63 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -1132,12 +1132,10 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
if (result)
goto out_unlock;
- if (mapping->nrpages) {
- result = invalidate_inode_pages2_range(mapping,
- pos >> PAGE_CACHE_SHIFT, end);
- if (result)
- goto out_unlock;
- }
+ result = invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT, end);
+ if (result)
+ goto out_unlock;
task_io_account_write(count);
@@ -1161,10 +1159,8 @@ ssize_t nfs_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
result = nfs_direct_write_schedule_iovec(dreq, iov, nr_segs, pos, uio);
- if (mapping->nrpages) {
- invalidate_inode_pages2_range(mapping,
- pos >> PAGE_CACHE_SHIFT, end);
- }
+ invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT, end);
mutex_unlock(&inode->i_mutex);
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index 8c06aed..779b05c 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -1065,10 +1065,11 @@ static int nfs_invalidate_mapping(struct inode *inode, struct address_space *map
if (ret < 0)
return ret;
}
- ret = invalidate_inode_pages2(mapping);
- if (ret < 0)
- return ret;
}
+ ret = invalidate_inode_pages2(mapping);
+ if (ret < 0)
+ return ret;
+
if (S_ISDIR(inode->i_mode)) {
spin_lock(&inode->i_lock);
memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 9a2193b..d758443 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -368,15 +368,15 @@ xfs_file_aio_read(
return ret;
}
- /*
- * Invalidate whole pages. This can return an error if
- * we fail to invalidate a page, but this should never
- * happen on XFS. Warn if it does fail.
- */
- ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping);
- WARN_ON_ONCE(ret);
- ret = 0;
}
+ /*
+ * Invalidate whole pages. This can return an error if
+ * we fail to invalidate a page, but this should never
+ * happen on XFS. Warn if it does fail.
+ */
+ ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping);
+ WARN_ON_ONCE(ret);
+ ret = 0;
xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
}
diff --git a/mm/filemap.c b/mm/filemap.c
index 16517c6..8e608fc 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2598,18 +2598,16 @@ generic_file_direct_write_iter(struct kiocb *iocb, struct iov_iter *iter,
* about to write. We do this *before* the write so that we can return
* without clobbering -EIOCBQUEUED from ->direct_IO().
*/
- if (mapping->nrpages) {
- written = invalidate_inode_pages2_range(mapping,
- pos >> PAGE_CACHE_SHIFT, end);
- /*
- * If a page can not be invalidated, return 0 to fall back
- * to buffered write.
- */
- if (written) {
- if (written == -EBUSY)
- return 0;
- goto out;
- }
+ written = invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT, end);
+ /*
+ * If a page can not be invalidated, return 0 to fall back
+ * to buffered write.
+ */
+ if (written) {
+ if (written == -EBUSY)
+ return 0;
+ goto out;
}
written = mapping_direct_IO(mapping, WRITE, iocb, iter, pos);
@@ -2622,10 +2620,8 @@ generic_file_direct_write_iter(struct kiocb *iocb, struct iov_iter *iter,
* so we don't support it 100%. If this invalidation
* fails, tough, the write still worked...
*/
- if (mapping->nrpages) {
- invalidate_inode_pages2_range(mapping,
- pos >> PAGE_CACHE_SHIFT, end);
- }
+ invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT, end);
if (written > 0) {
pos += written;
diff --git a/mm/truncate.c b/mm/truncate.c
index f460e67..f015a86 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -628,6 +628,10 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
int did_range_unmap = 0;
cleancache_invalidate_inode(mapping);
+
+ if (mapping->nrpages == 0)
+ return 0;
+
pagevec_init(&pvec, 0);
index = start;
while (index <= end && __pagevec_lookup(&pvec, mapping, index,
--
2.10.2
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