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| author | Andreas Gruenbacher <agruenba@redhat.com> | 2021-06-01 22:53:27 +0200 |
|---|---|---|
| committer | Andreas Gruenbacher <agruenba@redhat.com> | 2021-06-01 23:16:42 +0200 |
| commit | d5b8145455c629e7f157d2da46a9b2fba483f235 (patch) | |
| tree | a940ad03fdaffc9b7914cfb6e466d01f37861713 | |
| parent | c2131f7e73c9e9365613e323d65c7b9e5b910f56 (diff) | |
| download | linux-d5b8145455c629e7f157d2da46a9b2fba483f235.tar.bz2 | |
Revert "gfs2: Fix mmap locking for write faults"
This reverts commit b7f55d928e75557295c1ac280c291b738905b6fb.
As explained by Linus in [*], write faults on a mmap region are reads
from a filesysten point of view, so taking the inode glock exclusively
on write faults is incorrect.
Instead, when a page is marked writable, the .page_mkwrite vm operation
will be called, which is where the exclusive lock taking needs to
happen. I got this wrong because of a broken test case that made me
believe .page_mkwrite isn't getting called when it actually is.
[*] https://lore.kernel.org/lkml/CAHk-=wj8EWr_D65i4oRSj2FTbrc6RdNydNNCGxeabRnwtoU=3Q@mail.gmail.com/
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
| -rw-r--r-- | fs/gfs2/file.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 8a35a0196b6d..493a83e3f590 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -540,11 +540,9 @@ static vm_fault_t gfs2_fault(struct vm_fault *vmf) struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder gh; vm_fault_t ret; - u16 state; int err; - state = (vmf->flags & FAULT_FLAG_WRITE) ? LM_ST_EXCLUSIVE : LM_ST_SHARED; - gfs2_holder_init(ip->i_gl, state, 0, &gh); + gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh); err = gfs2_glock_nq(&gh); if (err) { ret = block_page_mkwrite_return(err); |