[PATCH 3/5] xfs: always hold the iolock when calling xfs_change_file_space

Christoph Hellwig
2013-10-12T07:56:43Z

[-- Attachment #1: xfs-kill-XFS_ATTR_NOLOCK --]
[-- Type: text/plain, Size: 8022 bytes --]

Currently fallocate always holds the iolock when calling into
xfs_change_file_space, while the ioctl path lets some of the lower level
functions take it, but leave it out in others.

This patch makes sure the ioctl path also always holds the iolock and
thus introduces consistent locking for the preallocation operations while
simplifying the code and allowing to kill the now unused XFS_ATTR_NOLOCK
flag.

Signed-off-by: Christoph Hellwig <hch@lst.de>

---
fs/xfs/xfs_bmap_util.c | 71 ++++++++++++++++---------------------------------
fs/xfs/xfs_file.c | 2 -
fs/xfs/xfs_ioctl.c | 2 +
fs/xfs/xfs_iops.h | 1
4 files changed, 27 insertions(+), 49 deletions(-)

Index: xfs/fs/xfs/xfs_file.c
===================================================================
--- xfs.orig/fs/xfs/xfs_file.c 2013-10-01 20:19:12.000000000 +0200
+++ xfs/fs/xfs/xfs_file.c 2013-10-01 20:21:00.720144850 +0200
@@ -816,7 +816,7 @@ xfs_file_fallocate(
xfs_flock64_t bf;
xfs_inode_t *ip = XFS_I(inode);
int cmd = XFS_IOC_RESVSP;
- int attr_flags = XFS_ATTR_NOLOCK;
+ int attr_flags = 0;

if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
return -EOPNOTSUPP;
Index: xfs/fs/xfs/xfs_ioctl.c
===================================================================
--- xfs.orig/fs/xfs/xfs_ioctl.c 2013-10-01 20:16:53.000000000 +0200
+++ xfs/fs/xfs/xfs_ioctl.c 2013-10-01 20:21:00.724144850 +0200
@@ -670,7 +670,9 @@ xfs_ioc_space(
error = mnt_want_write_file(filp);
if (error)
return error;
+ xfs_ilock(ip, XFS_IOLOCK_EXCL);
error = xfs_change_file_space(ip, cmd, bf, filp->f_pos, attr_flags);
+ xfs_iunlock(ip, XFS_IOLOCK_EXCL);
mnt_drop_write_file(filp);
return -error;
}
Index: xfs/fs/xfs/xfs_bmap_util.c
===================================================================
--- xfs.orig/fs/xfs/xfs_bmap_util.c 2013-10-01 20:19:12.404142276 +0200
+++ xfs/fs/xfs/xfs_bmap_util.c 2013-10-01 20:22:25.328146861 +0200
@@ -989,8 +989,7 @@ xfs_alloc_file_space(
xfs_inode_t *ip,
xfs_off_t offset,
xfs_off_t len,
- int alloc_type,
- int attr_flags)
+ int alloc_type)
{
xfs_mount_t *mp = ip->i_mount;
xfs_off_t count;
@@ -1248,8 +1247,7 @@ STATIC int
xfs_free_file_space(
xfs_inode_t *ip,
xfs_off_t offset,
- xfs_off_t len,
- int attr_flags)
+ xfs_off_t len)
{
int committed;
int done;
@@ -1267,7 +1265,6 @@ xfs_free_file_space(
int rt;
xfs_fileoff_t startoffset_fsb;
xfs_trans_t *tp;
- int need_iolock = 1;

mp = ip->i_mount;

@@ -1284,20 +1281,15 @@ xfs_free_file_space(
startoffset_fsb = XFS_B_TO_FSB(mp, offset);
endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);

- if (attr_flags & XFS_ATTR_NOLOCK)
- need_iolock = 0;
- if (need_iolock) {
- xfs_ilock(ip, XFS_IOLOCK_EXCL);
- /* wait for the completion of any pending DIOs */
- inode_dio_wait(VFS_I(ip));
- }
+ /* wait for the completion of any pending DIOs */
+ inode_dio_wait(VFS_I(ip));

rounding = max_t(xfs_off_t, 1 << mp->m_sb.sb_blocklog, PAGE_CACHE_SIZE);
ioffset = offset & ~(rounding - 1);
error = -filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
ioffset, -1);
if (error)
- goto out_unlock_iolock;
+ goto out;
truncate_pagecache_range(VFS_I(ip), ioffset, -1);

/*
@@ -1311,7 +1303,7 @@ xfs_free_file_space(
error = xfs_bmapi_read(ip, startoffset_fsb, 1,
&imap, &nimap, 0);
if (error)
- goto out_unlock_iolock;
+ goto out;
ASSERT(nimap == 0 || nimap == 1);
if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
xfs_daddr_t block;
@@ -1326,7 +1318,7 @@ xfs_free_file_space(
error = xfs_bmapi_read(ip, endoffset_fsb - 1, 1,
&imap, &nimap, 0);
if (error)
- goto out_unlock_iolock;
+ goto out;
ASSERT(nimap == 0 || nimap == 1);
if (nimap && imap.br_startblock != HOLESTARTBLOCK) {
ASSERT(imap.br_startblock != DELAYSTARTBLOCK);
@@ -1412,18 +1404,15 @@ xfs_free_file_space(
xfs_iunlock(ip, XFS_ILOCK_EXCL);
}

- out_unlock_iolock:
- if (need_iolock)
- xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+ out:
return error;

error0:
xfs_bmap_cancel(&free_list);
error1:
xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | XFS_TRANS_ABORT);
- xfs_iunlock(ip, need_iolock ? (XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL) :
- XFS_ILOCK_EXCL);
- return error;
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ goto out;
}

@@ -1431,8 +1420,7 @@ STATIC int
xfs_zero_file_space(
struct xfs_inode *ip,
xfs_off_t offset,
- xfs_off_t len,
- int attr_flags)
+ xfs_off_t len)
{
struct xfs_mount *mp = ip->i_mount;
uint granularity;
@@ -1453,9 +1441,6 @@ xfs_zero_file_space(
ASSERT(start_boundary >= offset);
ASSERT(end_boundary <= offset + len);

- if (!(attr_flags & XFS_ATTR_NOLOCK))
- xfs_ilock(ip, XFS_IOLOCK_EXCL);
-
if (start_boundary < end_boundary - 1) {
/* punch out the page cache over the conversion range */
truncate_pagecache_range(VFS_I(ip), start_boundary,
@@ -1463,16 +1448,16 @@ xfs_zero_file_space(
/* convert the blocks */
error = xfs_alloc_file_space(ip, start_boundary,
end_boundary - start_boundary - 1,
- XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT,
- attr_flags);
+ XFS_BMAPI_PREALLOC | XFS_BMAPI_CONVERT);
if (error)
- goto out_unlock;
+ goto out;

/* We've handled the interior of the range, now for the edges */
- if (start_boundary != offset)
+ if (start_boundary != offset) {
error = xfs_iozero(ip, offset, start_boundary - offset);
- if (error)
- goto out_unlock;
+ if (error)
+ goto out;
+ }

if (end_boundary != offset + len)
error = xfs_iozero(ip, end_boundary,
@@ -1486,9 +1471,7 @@ xfs_zero_file_space(
error = xfs_iozero(ip, offset, len);
}

-out_unlock:
- if (!(attr_flags & XFS_ATTR_NOLOCK))
- xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+out:
return error;

}
@@ -1571,8 +1554,7 @@ xfs_change_file_space(
setprealloc = clrprealloc = 0;
switch (cmd) {
case XFS_IOC_ZERO_RANGE:
- error = xfs_zero_file_space(ip, startoffset, bf->l_len,
- attr_flags);
+ error = xfs_zero_file_space(ip, startoffset, bf->l_len);
if (error)
return error;
setprealloc = 1;
@@ -1581,7 +1563,7 @@ xfs_change_file_space(
case XFS_IOC_RESVSP:
case XFS_IOC_RESVSP64:
error = xfs_alloc_file_space(ip, startoffset, bf->l_len,
- XFS_BMAPI_PREALLOC, attr_flags);
+ XFS_BMAPI_PREALLOC);
if (error)
return error;
setprealloc = 1;
@@ -1589,8 +1571,8 @@ xfs_change_file_space(

case XFS_IOC_UNRESVSP:
case XFS_IOC_UNRESVSP64:
- if ((error = xfs_free_file_space(ip, startoffset, bf->l_len,
- attr_flags)))
+ error = xfs_free_file_space(ip, startoffset, bf->l_len);
+ if (error)
return error;
break;

@@ -1608,22 +1590,17 @@ xfs_change_file_space(
* truncate, direct IO) from racing against the transient
* allocated but not written state we can have here.
*/
- xfs_ilock(ip, XFS_IOLOCK_EXCL);
if (startoffset > fsize) {
error = xfs_alloc_file_space(ip, fsize,
- startoffset - fsize, 0,
- attr_flags | XFS_ATTR_NOLOCK);
- if (error) {
- xfs_iunlock(ip, XFS_IOLOCK_EXCL);
+ startoffset - fsize, 0);
+ if (error)
break;
- }
}

iattr.ia_valid = ATTR_SIZE;
iattr.ia_size = startoffset;

error = xfs_setattr_size(ip, &iattr);
- xfs_iunlock(ip, XFS_IOLOCK_EXCL);

if (error)
return error;
Index: xfs/fs/xfs/xfs_iops.h
===================================================================
--- xfs.orig/fs/xfs/xfs_iops.h 2013-10-01 20:19:51.160143197 +0200
+++ xfs/fs/xfs/xfs_iops.h 2013-10-01 20:21:19.416145295 +0200
@@ -31,7 +31,6 @@ extern void xfs_setup_inode(struct xfs_i
* Internal setattr interfaces.
*/
#define XFS_ATTR_DMI 0x01 /* invocation from a DMI function */
-#define XFS_ATTR_NOLOCK 0x04 /* Don't grab any conflicting locks */
#define XFS_ATTR_NOACL 0x08 /* Don't call xfs_acl_chmod */
#define XFS_ATTR_SYNC 0x10 /* synchronous operation required */