Andreas Gruenbacher 20f829999c gfs2: Rework read and page fault locking ... So far, gfs2 has taken the inode glocks inside the ->readpage and ->readahead address space operations. Since commit d4388340ae ("fs: convert mpage_readpages to mpage_readahead"), gfs2_readahead is passed the pages to read ahead locked. With that, the current holder of the inode glock may be trying to lock one of those pages while gfs2_readahead is trying to take the inode glock, resulting in a deadlock. Fix that by moving the lock taking to the higher-level ->read_iter file and ->fault vm operations. This also gets rid of an ugly lock inversion workaround in gfs2_readpage. The cache consistency model of filesystems like gfs2 is such that if data is found in the page cache, the data is up to date and can be used without taking any filesystem locks. If a page is not cached, filesystem locks must be taken before populating the page cache. To avoid taking the inode glock when the data is already cached, gfs2_file_read_iter first tries to read the data with the IOCB_NOIO flag set. If that fails, the inode glock is taken and the operation is retried with the IOCB_NOIO flag cleared. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>		2020-07-07 23:40:12 +02:00
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acl.c
acl.h
aops.c
aops.h
bmap.c
bmap.h
dentry.c
dir.c
dir.h
export.c
file.c
gfs2.h
glock.c
glock.h
glops.c
glops.h
incore.h
inode.c
inode.h
Kconfig
lock_dlm.c
log.c
log.h
lops.c
lops.h
main.c
Makefile
meta_io.c
meta_io.h
ops_fstype.c
quota.c
quota.h
recovery.c
recovery.h
rgrp.c
rgrp.h
super.c
super.h
sys.c
sys.h
trace_gfs2.h
trans.c
trans.h
util.c
util.h
xattr.c
xattr.h