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authorShuning Zhang <sunny.s.zhang@oracle.com>2019-11-05 21:16:34 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-11-06 08:47:08 -0800
commite74540b285569d2b1e14fe7aee92297078f235ce (patch)
treed0c7128a3c2d5baf0e9904938b77a97eabb22f74
parent169226f7e0d275c1879551f37484ef6683579a5c (diff)
downloadlinux-e74540b285569d2b1e14fe7aee92297078f235ce.tar.bz2
ocfs2: protect extent tree in ocfs2_prepare_inode_for_write()
When the extent tree is modified, it should be protected by inode cluster lock and ip_alloc_sem. The extent tree is accessed and modified in the ocfs2_prepare_inode_for_write, but isn't protected by ip_alloc_sem. The following is a case. The function ocfs2_fiemap is accessing the extent tree, which is modified at the same time. kernel BUG at fs/ocfs2/extent_map.c:475! invalid opcode: 0000 [#1] SMP Modules linked in: tun ocfs2 ocfs2_nodemanager configfs ocfs2_stackglue [...] CPU: 16 PID: 14047 Comm: o2info Not tainted 4.1.12-124.23.1.el6uek.x86_64 #2 Hardware name: Oracle Corporation ORACLE SERVER X7-2L/ASM, MB MECH, X7-2L, BIOS 42040600 10/19/2018 task: ffff88019487e200 ti: ffff88003daa4000 task.ti: ffff88003daa4000 RIP: ocfs2_get_clusters_nocache.isra.11+0x390/0x550 [ocfs2] Call Trace: ocfs2_fiemap+0x1e3/0x430 [ocfs2] do_vfs_ioctl+0x155/0x510 SyS_ioctl+0x81/0xa0 system_call_fastpath+0x18/0xd8 Code: 18 48 c7 c6 60 7f 65 a0 31 c0 bb e2 ff ff ff 48 8b 4a 40 48 8b 7a 28 48 c7 c2 78 2d 66 a0 e8 38 4f 05 00 e9 28 fe ff ff 0f 1f 00 <0f> 0b 66 0f 1f 44 00 00 bb 86 ff ff ff e9 13 fe ff ff 66 0f 1f RIP ocfs2_get_clusters_nocache.isra.11+0x390/0x550 [ocfs2] ---[ end trace c8aa0c8180e869dc ]--- Kernel panic - not syncing: Fatal exception Kernel Offset: disabled This issue can be reproduced every week in a production environment. This issue is related to the usage mode. If others use ocfs2 in this mode, the kernel will panic frequently. [akpm@linux-foundation.org: coding style fixes] [Fix new warning due to unused function by removing said function - Linus ] Link: http://lkml.kernel.org/r/1568772175-2906-2-git-send-email-sunny.s.zhang@oracle.com Signed-off-by: Shuning Zhang <sunny.s.zhang@oracle.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Gang He <ghe@suse.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <jiangqi903@gmail.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Jun Piao <piaojun@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/ocfs2/file.c134
1 files changed, 90 insertions, 44 deletions
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 53939bf9d7d2..9876db52913a 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2098,53 +2098,89 @@ static int ocfs2_is_io_unaligned(struct inode *inode, size_t count, loff_t pos)
return 0;
}
-static int ocfs2_prepare_inode_for_refcount(struct inode *inode,
- struct file *file,
- loff_t pos, size_t count,
- int *meta_level)
+static int ocfs2_inode_lock_for_extent_tree(struct inode *inode,
+ struct buffer_head **di_bh,
+ int meta_level,
+ int overwrite_io,
+ int write_sem,
+ int wait)
{
- int ret;
- struct buffer_head *di_bh = NULL;
- u32 cpos = pos >> OCFS2_SB(inode->i_sb)->s_clustersize_bits;
- u32 clusters =
- ocfs2_clusters_for_bytes(inode->i_sb, pos + count) - cpos;
+ int ret = 0;
- ret = ocfs2_inode_lock(inode, &di_bh, 1);
- if (ret) {
- mlog_errno(ret);
+ if (wait)
+ ret = ocfs2_inode_lock(inode, NULL, meta_level);
+ else
+ ret = ocfs2_try_inode_lock(inode,
+ overwrite_io ? NULL : di_bh, meta_level);
+ if (ret < 0)
goto out;
+
+ if (wait) {
+ if (write_sem)
+ down_write(&OCFS2_I(inode)->ip_alloc_sem);
+ else
+ down_read(&OCFS2_I(inode)->ip_alloc_sem);
+ } else {
+ if (write_sem)
+ ret = down_write_trylock(&OCFS2_I(inode)->ip_alloc_sem);
+ else
+ ret = down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem);
+
+ if (!ret) {
+ ret = -EAGAIN;
+ goto out_unlock;
+ }
}
- *meta_level = 1;
+ return ret;
- ret = ocfs2_refcount_cow(inode, di_bh, cpos, clusters, UINT_MAX);
- if (ret)
- mlog_errno(ret);
+out_unlock:
+ brelse(*di_bh);
+ ocfs2_inode_unlock(inode, meta_level);
out:
- brelse(di_bh);
return ret;
}
+static void ocfs2_inode_unlock_for_extent_tree(struct inode *inode,
+ struct buffer_head **di_bh,
+ int meta_level,
+ int write_sem)
+{
+ if (write_sem)
+ up_write(&OCFS2_I(inode)->ip_alloc_sem);
+ else
+ up_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+ brelse(*di_bh);
+ *di_bh = NULL;
+
+ if (meta_level >= 0)
+ ocfs2_inode_unlock(inode, meta_level);
+}
+
static int ocfs2_prepare_inode_for_write(struct file *file,
loff_t pos, size_t count, int wait)
{
int ret = 0, meta_level = 0, overwrite_io = 0;
+ int write_sem = 0;
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = d_inode(dentry);
struct buffer_head *di_bh = NULL;
+ u32 cpos;
+ u32 clusters;
/*
* We start with a read level meta lock and only jump to an ex
* if we need to make modifications here.
*/
for(;;) {
- if (wait)
- ret = ocfs2_inode_lock(inode, NULL, meta_level);
- else
- ret = ocfs2_try_inode_lock(inode,
- overwrite_io ? NULL : &di_bh, meta_level);
+ ret = ocfs2_inode_lock_for_extent_tree(inode,
+ &di_bh,
+ meta_level,
+ overwrite_io,
+ write_sem,
+ wait);
if (ret < 0) {
- meta_level = -1;
if (ret != -EAGAIN)
mlog_errno(ret);
goto out;
@@ -2156,15 +2192,8 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
*/
if (!wait && !overwrite_io) {
overwrite_io = 1;
- if (!down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem)) {
- ret = -EAGAIN;
- goto out_unlock;
- }
ret = ocfs2_overwrite_io(inode, di_bh, pos, count);
- brelse(di_bh);
- di_bh = NULL;
- up_read(&OCFS2_I(inode)->ip_alloc_sem);
if (ret < 0) {
if (ret != -EAGAIN)
mlog_errno(ret);
@@ -2183,7 +2212,10 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
* set inode->i_size at the end of a write. */
if (should_remove_suid(dentry)) {
if (meta_level == 0) {
- ocfs2_inode_unlock(inode, meta_level);
+ ocfs2_inode_unlock_for_extent_tree(inode,
+ &di_bh,
+ meta_level,
+ write_sem);
meta_level = 1;
continue;
}
@@ -2197,18 +2229,32 @@ static int ocfs2_prepare_inode_for_write(struct file *file,
ret = ocfs2_check_range_for_refcount(inode, pos, count);
if (ret == 1) {
- ocfs2_inode_unlock(inode, meta_level);
- meta_level = -1;
-
- ret = ocfs2_prepare_inode_for_refcount(inode,
- file,
- pos,
- count,
- &meta_level);
+ ocfs2_inode_unlock_for_extent_tree(inode,
+ &di_bh,
+ meta_level,
+ write_sem);
+ ret = ocfs2_inode_lock_for_extent_tree(inode,
+ &di_bh,
+ meta_level,
+ overwrite_io,
+ 1,
+ wait);
+ write_sem = 1;
+ if (ret < 0) {
+ if (ret != -EAGAIN)
+ mlog_errno(ret);
+ goto out;
+ }
+
+ cpos = pos >> OCFS2_SB(inode->i_sb)->s_clustersize_bits;
+ clusters =
+ ocfs2_clusters_for_bytes(inode->i_sb, pos + count) - cpos;
+ ret = ocfs2_refcount_cow(inode, di_bh, cpos, clusters, UINT_MAX);
}
if (ret < 0) {
- mlog_errno(ret);
+ if (ret != -EAGAIN)
+ mlog_errno(ret);
goto out_unlock;
}
@@ -2219,10 +2265,10 @@ out_unlock:
trace_ocfs2_prepare_inode_for_write(OCFS2_I(inode)->ip_blkno,
pos, count, wait);
- brelse(di_bh);
-
- if (meta_level >= 0)
- ocfs2_inode_unlock(inode, meta_level);
+ ocfs2_inode_unlock_for_extent_tree(inode,
+ &di_bh,
+ meta_level,
+ write_sem);
out:
return ret;