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-rw-r--r--Documentation/ABI/testing/sysfs-class-bdi8
-rw-r--r--Documentation/filesystems/vfat.txt10
-rw-r--r--Documentation/vm/remap_file_pages.txt7
3 files changed, 21 insertions, 4 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-bdi b/Documentation/ABI/testing/sysfs-class-bdi
index d773d5697cf5..3187a18af6da 100644
--- a/Documentation/ABI/testing/sysfs-class-bdi
+++ b/Documentation/ABI/testing/sysfs-class-bdi
@@ -53,3 +53,11 @@ stable_pages_required (read-only)
If set, the backing device requires that all pages comprising a write
request must not be changed until writeout is complete.
+
+strictlimit (read-write)
+
+ Forces per-BDI checks for the share of given device in the write-back
+ cache even before the global background dirty limit is reached. This
+ is useful in situations where the global limit is much higher than
+ affordable for given relatively slow (or untrusted) device. Turning
+ strictlimit on has no visible effect if max_ratio is equal to 100%.
diff --git a/Documentation/filesystems/vfat.txt b/Documentation/filesystems/vfat.txt
index ce1126aceed8..223c32171dcc 100644
--- a/Documentation/filesystems/vfat.txt
+++ b/Documentation/filesystems/vfat.txt
@@ -180,6 +180,16 @@ dos1xfloppy -- If set, use a fallback default BIOS Parameter Block
<bool>: 0,1,yes,no,true,false
+LIMITATION
+---------------------------------------------------------------------
+* The fallocated region of file is discarded at umount/evict time
+ when using fallocate with FALLOC_FL_KEEP_SIZE.
+ So, User should assume that fallocated region can be discarded at
+ last close if there is memory pressure resulting in eviction of
+ the inode from the memory. As a result, for any dependency on
+ the fallocated region, user should make sure to recheck fallocate
+ after reopening the file.
+
TODO
----------------------------------------------------------------------
* Need to get rid of the raw scanning stuff. Instead, always use
diff --git a/Documentation/vm/remap_file_pages.txt b/Documentation/vm/remap_file_pages.txt
index 560e4363a55d..f609142f406a 100644
--- a/Documentation/vm/remap_file_pages.txt
+++ b/Documentation/vm/remap_file_pages.txt
@@ -18,10 +18,9 @@ on 32-bit systems to map files bigger than can linearly fit into 32-bit
virtual address space. This use-case is not critical anymore since 64-bit
systems are widely available.
-The plan is to deprecate the syscall and replace it with an emulation.
-The emulation will create new VMAs instead of nonlinear mappings. It's
-going to work slower for rare users of remap_file_pages() but ABI is
-preserved.
+The syscall is deprecated and replaced it with an emulation now. The
+emulation creates new VMAs instead of nonlinear mappings. It's going to
+work slower for rare users of remap_file_pages() but ABI is preserved.
One side effect of emulation (apart from performance) is that user can hit
vm.max_map_count limit more easily due to additional VMAs. See comment for