From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Andreas Gruenbacher <agruenba@redhat.com>,
Anand Jain <anand.jain@oracle.com>
Subject: [PATCH 5.15 21/33] gfs2: Move the inode glock locking to gfs2_file_buffered_write
Date: Fri, 29 Apr 2022 12:42:08 +0200 [thread overview]
Message-ID: <20220429104052.953769075@linuxfoundation.org> (raw)
In-Reply-To: <20220429104052.345760505@linuxfoundation.org>
From: Andreas Gruenbacher <agruenba@redhat.com>
commit b924bdab7445946e2ed364a0e6e249d36f1f1158 upstream
So far, for buffered writes, we were taking the inode glock in
gfs2_iomap_begin and dropping it in gfs2_iomap_end with the intention of
not holding the inode glock while iomap_write_actor faults in user
pages. It turns out that iomap_write_actor is called inside iomap_begin
... iomap_end, so the user pages were still faulted in while holding the
inode glock and the locking code in iomap_begin / iomap_end was
completely pointless.
Move the locking into gfs2_file_buffered_write instead. We'll take care
of the potential deadlocks due to faulting in user pages while holding a
glock in a subsequent patch.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/gfs2/bmap.c | 60 ---------------------------------------------------------
fs/gfs2/file.c | 27 +++++++++++++++++++++++++
2 files changed, 28 insertions(+), 59 deletions(-)
--- a/fs/gfs2/bmap.c
+++ b/fs/gfs2/bmap.c
@@ -961,46 +961,6 @@ hole_found:
goto out;
}
-static int gfs2_write_lock(struct inode *inode)
-{
- struct gfs2_inode *ip = GFS2_I(inode);
- struct gfs2_sbd *sdp = GFS2_SB(inode);
- int error;
-
- gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
- error = gfs2_glock_nq(&ip->i_gh);
- if (error)
- goto out_uninit;
- if (&ip->i_inode == sdp->sd_rindex) {
- struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
-
- error = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
- GL_NOCACHE, &m_ip->i_gh);
- if (error)
- goto out_unlock;
- }
- return 0;
-
-out_unlock:
- gfs2_glock_dq(&ip->i_gh);
-out_uninit:
- gfs2_holder_uninit(&ip->i_gh);
- return error;
-}
-
-static void gfs2_write_unlock(struct inode *inode)
-{
- struct gfs2_inode *ip = GFS2_I(inode);
- struct gfs2_sbd *sdp = GFS2_SB(inode);
-
- if (&ip->i_inode == sdp->sd_rindex) {
- struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
-
- gfs2_glock_dq_uninit(&m_ip->i_gh);
- }
- gfs2_glock_dq_uninit(&ip->i_gh);
-}
-
static int gfs2_iomap_page_prepare(struct inode *inode, loff_t pos,
unsigned len)
{
@@ -1118,11 +1078,6 @@ out_qunlock:
return ret;
}
-static inline bool gfs2_iomap_need_write_lock(unsigned flags)
-{
- return (flags & IOMAP_WRITE) && !(flags & IOMAP_DIRECT);
-}
-
static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
unsigned flags, struct iomap *iomap,
struct iomap *srcmap)
@@ -1135,12 +1090,6 @@ static int gfs2_iomap_begin(struct inode
iomap->flags |= IOMAP_F_BUFFER_HEAD;
trace_gfs2_iomap_start(ip, pos, length, flags);
- if (gfs2_iomap_need_write_lock(flags)) {
- ret = gfs2_write_lock(inode);
- if (ret)
- goto out;
- }
-
ret = __gfs2_iomap_get(inode, pos, length, flags, iomap, &mp);
if (ret)
goto out_unlock;
@@ -1168,10 +1117,7 @@ static int gfs2_iomap_begin(struct inode
ret = gfs2_iomap_begin_write(inode, pos, length, flags, iomap, &mp);
out_unlock:
- if (ret && gfs2_iomap_need_write_lock(flags))
- gfs2_write_unlock(inode);
release_metapath(&mp);
-out:
trace_gfs2_iomap_end(ip, iomap, ret);
return ret;
}
@@ -1219,15 +1165,11 @@ static int gfs2_iomap_end(struct inode *
}
if (unlikely(!written))
- goto out_unlock;
+ return 0;
if (iomap->flags & IOMAP_F_SIZE_CHANGED)
mark_inode_dirty(inode);
set_bit(GLF_DIRTY, &ip->i_gl->gl_flags);
-
-out_unlock:
- if (gfs2_iomap_need_write_lock(flags))
- gfs2_write_unlock(inode);
return 0;
}
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -881,13 +881,40 @@ static ssize_t gfs2_file_buffered_write(
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
ssize_t ret;
+ gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &ip->i_gh);
+ ret = gfs2_glock_nq(&ip->i_gh);
+ if (ret)
+ goto out_uninit;
+
+ if (inode == sdp->sd_rindex) {
+ struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
+
+ ret = gfs2_glock_nq_init(m_ip->i_gl, LM_ST_EXCLUSIVE,
+ GL_NOCACHE, &m_ip->i_gh);
+ if (ret)
+ goto out_unlock;
+ }
+
current->backing_dev_info = inode_to_bdi(inode);
ret = iomap_file_buffered_write(iocb, from, &gfs2_iomap_ops);
current->backing_dev_info = NULL;
if (ret > 0)
iocb->ki_pos += ret;
+
+ if (inode == sdp->sd_rindex) {
+ struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode);
+
+ gfs2_glock_dq_uninit(&m_ip->i_gh);
+ }
+
+out_unlock:
+ gfs2_glock_dq(&ip->i_gh);
+out_uninit:
+ gfs2_holder_uninit(&ip->i_gh);
return ret;
}
next prev parent reply other threads:[~2022-04-29 10:45 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-29 10:41 [PATCH 5.15 00/33] 5.15.37-rc1 review Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 01/33] floppy: disable FDRAWCMD by default Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 02/33] bpf: Introduce composable reg, ret and arg types Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 03/33] bpf: Replace ARG_XXX_OR_NULL with ARG_XXX | PTR_MAYBE_NULL Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 04/33] bpf: Replace RET_XXX_OR_NULL with RET_XXX " Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 05/33] bpf: Replace PTR_TO_XXX_OR_NULL with PTR_TO_XXX " Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 06/33] bpf: Introduce MEM_RDONLY flag Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 07/33] bpf: Convert PTR_TO_MEM_OR_NULL to composable types Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 08/33] bpf: Make per_cpu_ptr return rdonly PTR_TO_MEM Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 09/33] bpf: Add MEM_RDONLY for helper args that are pointers to rdonly mem Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 10/33] bpf/selftests: Test PTR_TO_RDONLY_MEM Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 11/33] bpf: Fix crash due to out of bounds access into reg2btf_ids Greg Kroah-Hartman
2022-04-29 10:41 ` [PATCH 5.15 12/33] spi: cadence-quadspi: fix write completion support Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 13/33] ARM: dts: socfpga: change qspi to "intel,socfpga-qspi" Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 14/33] mm: kfence: fix objcgs vector allocation Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 15/33] gup: Turn fault_in_pages_{readable,writeable} into fault_in_{readable,writeable} Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 16/33] iov_iter: Turn iov_iter_fault_in_readable into fault_in_iov_iter_readable Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 17/33] iov_iter: Introduce fault_in_iov_iter_writeable Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 18/33] gfs2: Add wrapper for iomap_file_buffered_write Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 19/33] gfs2: Clean up function may_grant Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 20/33] gfs2: Introduce flag for glock holder auto-demotion Greg Kroah-Hartman
2022-04-29 10:42 ` Greg Kroah-Hartman [this message]
2022-04-29 10:42 ` [PATCH 5.15 22/33] gfs2: Eliminate ip->i_gh Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 23/33] gfs2: Fix mmap + page fault deadlocks for buffered I/O Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 24/33] iomap: Fix iomap_dio_rw return value for user copies Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 25/33] iomap: Support partial direct I/O on user copy failures Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 26/33] iomap: Add done_before argument to iomap_dio_rw Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 27/33] gup: Introduce FOLL_NOFAULT flag to disable page faults Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 28/33] iov_iter: Introduce nofault " Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 29/33] gfs2: Fix mmap + page fault deadlocks for direct I/O Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 30/33] btrfs: fix deadlock due to page faults during direct IO reads and writes Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 31/33] btrfs: fallback to blocking mode when doing async dio over multiple extents Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 32/33] mm: gup: make fault_in_safe_writeable() use fixup_user_fault() Greg Kroah-Hartman
2022-04-29 10:42 ` [PATCH 5.15 33/33] selftests/bpf: Add test for reg2btf_ids out of bounds access Greg Kroah-Hartman
2022-06-24 10:33 ` Po-Hsu Lin
2022-06-24 11:09 ` Greg Kroah-Hartman
2022-07-01 12:51 ` Po-Hsu Lin
2022-04-29 16:39 ` [PATCH 5.15 00/33] 5.15.37-rc1 review Florian Fainelli
2022-04-29 18:36 ` Shuah Khan
2022-04-29 21:14 ` Naresh Kamboju
2022-04-29 23:47 ` Guenter Roeck
2022-04-29 23:54 ` Ron Economos
2022-04-30 10:17 ` Sudip Mukherjee
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