https://github.com/torvalds/linux
Revision 914ee295af418e936ec20a08c1663eaabe4cd07a authored by Xin Zhong on 09 December 2010, 09:30:14 UTC, committed by Chris Mason on 10 December 2010, 21:29:10 UTC
This problem is found in meego testing: http://bugs.meego.com/show_bug.cgi?id=6672 A file in btrfs is mmaped and the mmaped buffer is passed to pwrite to write to the same page of the same file. In btrfs_file_aio_write(), the pages is locked by prepare_pages(). So when btrfs_copy_from_user() is called, page fault happens and the same page needs to be locked again in filemap_fault(). The fix is to move iov_iter_fault_in_readable() before prepage_pages() to make page fault happen before pages are locked. And also disable page fault in critical region in btrfs_copy_from_user(). Reviewed-by: Yan, Zheng<zheng.z.yan@intel.com> Signed-off-by: Zhong, Xin <xin.zhong@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
1 parent f106e82
Tip revision: 914ee295af418e936ec20a08c1663eaabe4cd07a authored by Xin Zhong on 09 December 2010, 09:30:14 UTC
Btrfs: pwrite blocked when writing from the mmaped buffer of the same page
Btrfs: pwrite blocked when writing from the mmaped buffer of the same page
Tip revision: 914ee29
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coccinelle | ||
dtc | ||
genksyms | ||
kconfig | ||
ksymoops | ||
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selinux | ||
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Lindent | -rwxr-xr-x | 460 bytes |
Makefile | -rw-r--r-- | 934 bytes |
Makefile.build | -rw-r--r-- | 12.1 KB |
Makefile.clean | -rw-r--r-- | 3.2 KB |
Makefile.fwinst | -rw-r--r-- | 2.0 KB |
Makefile.headersinst | -rw-r--r-- | 3.2 KB |
Makefile.help | -rw-r--r-- | 68 bytes |
Makefile.host | -rw-r--r-- | 6.5 KB |
Makefile.lib | -rw-r--r-- | 9.1 KB |
Makefile.modbuiltin | -rw-r--r-- | 1.8 KB |
Makefile.modinst | -rw-r--r-- | 1.0 KB |
Makefile.modpost | -rw-r--r-- | 5.1 KB |
bin2c.c | -rw-r--r-- | 702 bytes |
bloat-o-meter | -rwxr-xr-x | 1.7 KB |
bootgraph.pl | -rw-r--r-- | 5.6 KB |
checkincludes.pl | -rwxr-xr-x | 1.8 KB |
checkkconfigsymbols.sh | -rwxr-xr-x | 1.8 KB |
checkpatch.pl | -rwxr-xr-x | 75.5 KB |
checkstack.pl | -rwxr-xr-x | 5.2 KB |
checksyscalls.sh | -rwxr-xr-x | 5.5 KB |
checkversion.pl | -rwxr-xr-x | 1.8 KB |
cleanfile | -rwxr-xr-x | 3.4 KB |
cleanpatch | -rwxr-xr-x | 5.0 KB |
coccicheck | -rwxr-xr-x | 2.0 KB |
config | -rwxr-xr-x | 2.6 KB |
conmakehash.c | -rw-r--r-- | 6.0 KB |
decodecode | -rwxr-xr-x | 1.9 KB |
diffconfig | -rwxr-xr-x | 3.6 KB |
export_report.pl | -rw-r--r-- | 4.2 KB |
extract-ikconfig | -rwxr-xr-x | 1.3 KB |
gcc-version.sh | -rw-r--r-- | 819 bytes |
gcc-x86_32-has-stack-protector.sh | -rw-r--r-- | 183 bytes |
gcc-x86_64-has-stack-protector.sh | -rw-r--r-- | 199 bytes |
gen_initramfs_list.sh | -rw-r--r-- | 7.1 KB |
get_maintainer.pl | -rwxr-xr-x | 34.3 KB |
gfp-translate | -rw-r--r-- | 1.5 KB |
headerdep.pl | -rwxr-xr-x | 3.5 KB |
headers.sh | -rwxr-xr-x | 512 bytes |
headers_check.pl | -rw-r--r-- | 2.7 KB |
headers_install.pl | -rw-r--r-- | 1.5 KB |
kallsyms.c | -rw-r--r-- | 15.2 KB |
kernel-doc | -rwxr-xr-x | 62.1 KB |
makelst | -rwxr-xr-x | 773 bytes |
markup_oops.pl | -rw-r--r-- | 8.1 KB |
mkcompile_h | -rwxr-xr-x | 2.5 KB |
mkmakefile | -rw-r--r-- | 1.1 KB |
mksysmap | -rw-r--r-- | 1.3 KB |
mkuboot.sh | -rwxr-xr-x | 379 bytes |
mkversion | -rw-r--r-- | 74 bytes |
module-common.lds | -rw-r--r-- | 210 bytes |
namespace.pl | -rwxr-xr-x | 13.0 KB |
patch-kernel | -rwxr-xr-x | 9.8 KB |
pnmtologo.c | -rw-r--r-- | 11.7 KB |
profile2linkerlist.pl | -rw-r--r-- | 375 bytes |
recordmcount.pl | -rwxr-xr-x | 17.2 KB |
setlocalversion | -rwxr-xr-x | 3.7 KB |
show_delta | -rwxr-xr-x | 3.0 KB |
tags.sh | -rwxr-xr-x | 4.6 KB |
unifdef.c | -rw-r--r-- | 31.6 KB |
ver_linux | -rwxr-xr-x | 3.1 KB |
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