The patch titled
mm: pagecache write deadlocks EFAULT fix
has been removed from the -mm tree. Its filename was
mm-fix-pagecache-write-deadlocks-mm-pagecache-write-deadlocks-efault-fix.patch
This patch was dropped because it is obsolete
------------------------------------------------------
Subject: mm: pagecache write deadlocks EFAULT fix
From: Nick Piggin <npiggin@xxxxxxx>
Fix buffered writes to handle -EFAULT properly.
Also, pass 'seglen' rather than 'bytes' to fault_in_pages_readable in the
DEBUG_VM case, which matches !DEBUG_VM and is the correct thing to do.
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
Acked-by: Badari Pulavarty <pbadari@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
include/linux/pagemap.h | 5 +++--
mm/filemap.c | 12 ++++++++++--
2 files changed, 13 insertions(+), 4 deletions(-)
diff -puN include/linux/pagemap.h~mm-fix-pagecache-write-deadlocks-mm-pagecache-write-deadlocks-efault-fix include/linux/pagemap.h
--- a/include/linux/pagemap.h~mm-fix-pagecache-write-deadlocks-mm-pagecache-write-deadlocks-efault-fix
+++ a/include/linux/pagemap.h
@@ -217,7 +217,7 @@ static inline int fault_in_pages_writeab
return ret;
}
-static inline void fault_in_pages_readable(const char __user *uaddr, int size)
+static inline int fault_in_pages_readable(const char __user *uaddr, int size)
{
volatile char c;
int ret;
@@ -228,8 +228,9 @@ static inline void fault_in_pages_readab
if (((unsigned long)uaddr & PAGE_MASK) !=
((unsigned long)end & PAGE_MASK))
- __get_user(c, end);
+ ret = __get_user(c, end);
}
+ return ret;
}
#endif /* _LINUX_PAGEMAP_H */
diff -puN mm/filemap.c~mm-fix-pagecache-write-deadlocks-mm-pagecache-write-deadlocks-efault-fix mm/filemap.c
--- a/mm/filemap.c~mm-fix-pagecache-write-deadlocks-mm-pagecache-write-deadlocks-efault-fix
+++ a/mm/filemap.c
@@ -2110,8 +2110,14 @@ retry_noprogress:
* Bring in the user page that we will copy from _first_, this
* minimises the chance we have to break into the slowpath
* below.
+ *
+ * Must check for -EFAULT here, because an unhandled pagefault
+ * from the atomic copy below may not actually be due to an
+ * unmapped user region.
*/
- fault_in_pages_readable(buf, seglen);
+ status = fault_in_pages_readable(buf, seglen);
+ if (unlikely(status))
+ break;
#endif
page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
@@ -2202,7 +2208,9 @@ retry_noprogress:
}
} else {
#ifdef CONFIG_DEBUG_VM
- fault_in_pages_readable(buf, bytes);
+ status = fault_in_pages_readable(buf, seglen);
+ if (unlikely(status))
+ break;
#endif
/*
* OK, we took a fault without making progress. Fall
_
Patches currently in -mm which might be from npiggin@xxxxxxx are
mm-only-mm-debug-write-deadlocks.patch
mm-fix-pagecache-write-deadlocks.patch
mm-fix-pagecache-write-deadlocks-mm-pagecache-write-deadlocks-efault-fix.patch
mm-fix-pagecache-write-deadlocks-zerolength-fix.patch
mm-fix-pagecache-write-deadlocks-stale-holes-fix.patch
fs-prepare_write-fixes.patch
fs-prepare_write-fixes-fuse-fix.patch
fs-prepare_write-fixes-jffs-fix.patch
fs-prepare_write-fixes-fat-fix.patch
fs-fix-cont-vs-deadlock-patches.patch
git-block.patch
buffer-memorder-fix.patch
sched-avoid-div-in-rebalance_tick.patch
fs-libfs-buffered-write-leak-fix.patch
mm-revert-generic_file_buffered_write-handle-zero-length-iovec-segments.patch
mm-revert-generic_file_buffered_write-deadlock-on-vectored-write.patch
mm-generic_file_buffered_write-cleanup.patch
mm-debug-write-deadlocks.patch
mm-be-sure-to-trim-blocks.patch
mm-cleanup-pagecache-insertion-operations.patch
mm-generic_file_buffered_write-iovec-cleanup.patch
-
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