Skip to content

Commit

Permalink
Linux 4.7 compat: use iterate_shared for concurrent readdir
Browse files Browse the repository at this point in the history
Register iterate_shared if it exists so the kernel will used shared
lock and allowing concurrent readdir.

Also, use shared lock when doing llseek with SEEK_DATA or SEEK_HOLE
to allow concurrent seeking.

Signed-off-by: Chunwei Chen <[email protected]>
Signed-off-by: Brian Behlendorf <[email protected]>
Closes openzfs#4664
Closes openzfs#4665
  • Loading branch information
Chunwei Chen committed Sep 7, 2016
1 parent 2e8df2c commit b732379
Show file tree
Hide file tree
Showing 4 changed files with 54 additions and 25 deletions.
49 changes: 35 additions & 14 deletions config/kernel-vfs-iterate.m4
Original file line number Diff line number Diff line change
@@ -1,43 +1,64 @@
dnl #
dnl # 3.11 API change
dnl #
AC_DEFUN([ZFS_AC_KERNEL_VFS_ITERATE], [
AC_MSG_CHECKING([whether fops->iterate() is available])
dnl #
dnl # 4.7 API change
dnl #
AC_MSG_CHECKING([whether fops->iterate_shared() is available])
ZFS_LINUX_TRY_COMPILE([
#include <linux/fs.h>
int iterate(struct file *filp, struct dir_context * context)
{ return 0; }
static const struct file_operations fops
__attribute__ ((unused)) = {
.iterate = iterate,
.iterate_shared = iterate,
};
],[
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_VFS_ITERATE, 1,
[fops->iterate() is available])
AC_DEFINE(HAVE_VFS_ITERATE_SHARED, 1,
[fops->iterate_shared() is available])
],[
AC_MSG_RESULT(no)
AC_MSG_CHECKING([whether fops->readdir() is available])
dnl #
dnl # 3.11 API change
dnl #
AC_MSG_CHECKING([whether fops->iterate() is available])
ZFS_LINUX_TRY_COMPILE([
#include <linux/fs.h>
int readdir(struct file *filp, void *entry, filldir_t func)
int iterate(struct file *filp, struct dir_context * context)
{ return 0; }
static const struct file_operations fops
__attribute__ ((unused)) = {
.readdir = readdir,
.iterate = iterate,
};
],[
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_VFS_READDIR, 1,
[fops->readdir() is available])
AC_DEFINE(HAVE_VFS_ITERATE, 1,
[fops->iterate() is available])
],[
AC_MSG_ERROR(no; file a bug report with ZFSOnLinux)
])
AC_MSG_RESULT(no)
AC_MSG_CHECKING([whether fops->readdir() is available])
ZFS_LINUX_TRY_COMPILE([
#include <linux/fs.h>
int readdir(struct file *filp, void *entry, filldir_t func)
{ return 0; }
static const struct file_operations fops
__attribute__ ((unused)) = {
.readdir = readdir,
};
],[
],[
AC_MSG_RESULT(yes)
AC_DEFINE(HAVE_VFS_READDIR, 1,
[fops->readdir() is available])
],[
AC_MSG_ERROR(no; file a bug report with ZFSOnLinux)
])
])
])
])
2 changes: 1 addition & 1 deletion include/sys/zpl.h
Original file line number Diff line number Diff line change
Expand Up @@ -123,7 +123,7 @@ extern const struct inode_operations zpl_ops_snapdirs;
extern const struct file_operations zpl_fops_shares;
extern const struct inode_operations zpl_ops_shares;

#ifdef HAVE_VFS_ITERATE
#if defined(HAVE_VFS_ITERATE) || defined(HAVE_VFS_ITERATE_SHARED)

#define DIR_CONTEXT_INIT(_dirent, _actor, _pos) { \
.actor = _actor, \
Expand Down
18 changes: 12 additions & 6 deletions module/zfs/zpl_ctldir.c
Original file line number Diff line number Diff line change
Expand Up @@ -81,7 +81,7 @@ zpl_root_iterate(struct file *filp, struct dir_context *ctx)
return (error);
}

#if !defined(HAVE_VFS_ITERATE)
#if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED)
static int
zpl_root_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
Expand Down Expand Up @@ -144,7 +144,9 @@ const struct file_operations zpl_fops_root = {
.open = zpl_common_open,
.llseek = generic_file_llseek,
.read = generic_read_dir,
#ifdef HAVE_VFS_ITERATE
#ifdef HAVE_VFS_ITERATE_SHARED
.iterate_shared = zpl_root_iterate,
#elif defined(HAVE_VFS_ITERATE)
.iterate = zpl_root_iterate,
#else
.readdir = zpl_root_readdir,
Expand Down Expand Up @@ -285,7 +287,7 @@ zpl_snapdir_iterate(struct file *filp, struct dir_context *ctx)
return (error);
}

#if !defined(HAVE_VFS_ITERATE)
#if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED)
static int
zpl_snapdir_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
Expand Down Expand Up @@ -385,7 +387,9 @@ const struct file_operations zpl_fops_snapdir = {
.open = zpl_common_open,
.llseek = generic_file_llseek,
.read = generic_read_dir,
#ifdef HAVE_VFS_ITERATE
#ifdef HAVE_VFS_ITERATE_SHARED
.iterate_shared = zpl_snapdir_iterate,
#elif defined(HAVE_VFS_ITERATE)
.iterate = zpl_snapdir_iterate,
#else
.readdir = zpl_snapdir_readdir,
Expand Down Expand Up @@ -472,7 +476,7 @@ zpl_shares_iterate(struct file *filp, struct dir_context *ctx)
return (error);
}

#if !defined(HAVE_VFS_ITERATE)
#if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED)
static int
zpl_shares_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
Expand Down Expand Up @@ -525,7 +529,9 @@ const struct file_operations zpl_fops_shares = {
.open = zpl_common_open,
.llseek = generic_file_llseek,
.read = generic_read_dir,
#ifdef HAVE_VFS_ITERATE
#ifdef HAVE_VFS_ITERATE_SHARED
.iterate_shared = zpl_shares_iterate,
#elif defined(HAVE_VFS_ITERATE)
.iterate = zpl_shares_iterate,
#else
.readdir = zpl_shares_readdir,
Expand Down
10 changes: 6 additions & 4 deletions module/zfs/zpl_file.c
Original file line number Diff line number Diff line change
Expand Up @@ -93,7 +93,7 @@ zpl_iterate(struct file *filp, struct dir_context *ctx)
return (error);
}

#if !defined(HAVE_VFS_ITERATE)
#if !defined(HAVE_VFS_ITERATE) && !defined(HAVE_VFS_ITERATE_SHARED)
static int
zpl_readdir(struct file *filp, void *dirent, filldir_t filldir)
{
Expand Down Expand Up @@ -419,13 +419,13 @@ zpl_llseek(struct file *filp, loff_t offset, int whence)
loff_t maxbytes = ip->i_sb->s_maxbytes;
loff_t error;

spl_inode_lock(ip);
spl_inode_lock_shared(ip);
cookie = spl_fstrans_mark();
error = -zfs_holey(ip, whence, &offset);
spl_fstrans_unmark(cookie);
if (error == 0)
error = lseek_execute(filp, ip, offset, maxbytes);
spl_inode_unlock(ip);
spl_inode_unlock_shared(ip);

return (error);
}
Expand Down Expand Up @@ -851,7 +851,9 @@ const struct file_operations zpl_file_operations = {
const struct file_operations zpl_dir_file_operations = {
.llseek = generic_file_llseek,
.read = generic_read_dir,
#ifdef HAVE_VFS_ITERATE
#ifdef HAVE_VFS_ITERATE_SHARED
.iterate_shared = zpl_iterate,
#elif defined(HAVE_VFS_ITERATE)
.iterate = zpl_iterate,
#else
.readdir = zpl_readdir,
Expand Down

0 comments on commit b732379

Please sign in to comment.