Merge pull request #605 from trapexit/man

add reference to 32bit mmap kernel bug

README.md

@@ -1,6 +1,6 @@
 % mergerfs(1) mergerfs user manual
 % Antonio SJ Musumeci <trapexit@spawn.link>
-% 2019-03-21
+% 2019-04-23
 
 # NAME
 
@@ -674,6 +674,13 @@ Try enabling the `use_ino` option. Some have reported that it fixes the issue.
 Be sure to turn off `direct_io`. rtorrent and some other applications use [mmap](http://linux.die.net/man/2/mmap) to read and write to files and offer no failback to traditional methods. FUSE does not currently support mmap while using `direct_io`. There may be a performance penalty on writes with `direct_io` off as well as the problem of double caching but it's the only way to get such applications to work. If the performance loss is too high for other apps you can mount mergerfs twice. Once with `direct_io` enabled and one without it. Be sure to set `dropcacheonclose=true` if not using `direct_io`.
 
 
+#### rtorrent fails with files >= 4GiB
+
+This is a kernel bug with mmap and FUSE on 32bit platforms. A fix should become available for all LTS releases.
+
+https://marc.info/?l=linux-fsdevel&m=155550785230874&w=2
+
+
 #### Plex doesn't work with mergerfs
 
 It does. If you're trying to put Plex's config / metadata on mergerfs you have to leave `direct_io` off because Plex is using sqlite which apparently needs mmap. mmap doesn't work with `direct_io`. To fix this place the data elsewhere or disable `direct_io` (with `dropcacheonclose=true`).

man/mergerfs.1

@@ -1,7 +1,7 @@
 .\"t
 .\" Automatically generated by Pandoc 1.19.2.4
 .\"
-.TH "mergerfs" "1" "2019\-03\-21" "mergerfs user manual" ""
+.TH "mergerfs" "1" "2019\-04\-23" "mergerfs user manual" ""
 .hy
 .SH NAME
 .PP
@@ -1386,6 +1386,12 @@ mergerfs twice.
 Once with \f[C]direct_io\f[] enabled and one without it.
 Be sure to set \f[C]dropcacheonclose=true\f[] if not using
 \f[C]direct_io\f[].
+.SS rtorrent fails with files >= 4GiB
+.PP
+This is a kernel bug with mmap and FUSE on 32bit platforms.
+A fix should become available for all LTS releases.
+.PP
+https://marc.info/?l=linux\-fsdevel&m=155550785230874&w=2
 .SS Plex doesn\[aq]t work with mergerfs
 .PP
 It does.