Generic code now blocks all writers from standard write paths. So we block all
writers coming from ioctl and replace blocking of transactions on frozen
filesystem with a debugging check. As a bonus, we get a protection of ioctl
against racing remount read-only. We also convert xfs_file_aio_write() to a
non-racy freeze protection.
CC: Ben Myers <bpm@xxxxxxx>
CC: Alex Elder <elder@xxxxxxxxxx>
CC: xfs@xxxxxxxxxxx
Signed-off-by: Jan Kara <jack@xxxxxxx>
---
fs/xfs/xfs_file.c | 10 ++++++--
fs/xfs/xfs_ioctl.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++--
fs/xfs/xfs_ioctl32.c | 12 ++++++++++
fs/xfs/xfs_iomap.c | 1 -
fs/xfs/xfs_mount.c | 2 +-
fs/xfs/xfs_mount.h | 3 --
fs/xfs/xfs_sync.c | 2 +-
fs/xfs/xfs_trans.c | 2 +-
8 files changed, 74 insertions(+), 13 deletions(-)
diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 7e5bc87..57dd20e 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -874,10 +874,12 @@ xfs_file_aio_write(
if (ocount == 0)
return 0;
- xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE);
+ sb_start_write(inode->i_sb);
- if (XFS_FORCED_SHUTDOWN(ip->i_mount))
- return -EIO;
+ if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
+ ret = -EIO;
+ goto out;
+ }
if (unlikely(file->f_flags & O_DIRECT))
ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
@@ -896,6 +898,8 @@ xfs_file_aio_write(
ret = err;
}
+out:
+ sb_end_write(inode->i_sb);
return ret;
}
diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 76f3ca5..7890105 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -367,9 +367,15 @@ xfs_fssetdm_by_handle(
if (copy_from_user(&dmhreq, arg, sizeof(xfs_fsop_setdm_handlereq_t)))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(parfilp);
+ if (error)
+ return error;
+
dentry = xfs_handlereq_to_dentry(parfilp, &dmhreq.hreq);
- if (IS_ERR(dentry))
+ if (IS_ERR(dentry)) {
+ mnt_drop_write_file(parfilp);
return PTR_ERR(dentry);
+ }
if (IS_IMMUTABLE(dentry->d_inode) || IS_APPEND(dentry->d_inode)) {
error = -XFS_ERROR(EPERM);
@@ -385,6 +391,7 @@ xfs_fssetdm_by_handle(
fsd.fsd_dmstate);
out:
+ mnt_drop_write_file(parfilp);
dput(dentry);
return error;
}
@@ -631,7 +638,11 @@ xfs_ioc_space(
if (ioflags & IO_INVIS)
attr_flags |= XFS_ATTR_DMI;
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
error = xfs_change_file_space(ip, cmd, bf, filp->f_pos, attr_flags);
+ mnt_drop_write_file(filp);
return -error;
}
@@ -1160,6 +1171,7 @@ xfs_ioc_fssetxattr(
{
struct fsxattr fa;
unsigned int mask;
+ int error;
if (copy_from_user(&fa, arg, sizeof(fa)))
return -EFAULT;
@@ -1168,7 +1180,12 @@ xfs_ioc_fssetxattr(
if (filp->f_flags & (O_NDELAY|O_NONBLOCK))
mask |= FSX_NONBLOCK;
- return -xfs_ioctl_setattr(ip, &fa, mask);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
+ error = xfs_ioctl_setattr(ip, &fa, mask);
+ mnt_drop_write_file(filp);
+ return -error;
}
STATIC int
@@ -1193,6 +1210,7 @@ xfs_ioc_setxflags(
struct fsxattr fa;
unsigned int flags;
unsigned int mask;
+ int error;
if (copy_from_user(&flags, arg, sizeof(flags)))
return -EFAULT;
@@ -1207,7 +1225,12 @@ xfs_ioc_setxflags(
mask |= FSX_NONBLOCK;
fa.fsx_xflags = xfs_merge_ioc_xflags(flags, xfs_ip2xflags(ip));
- return -xfs_ioctl_setattr(ip, &fa, mask);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
+ error = xfs_ioctl_setattr(ip, &fa, mask);
+ mnt_drop_write_file(filp);
+ return -error;
}
STATIC int
@@ -1382,8 +1405,13 @@ xfs_file_ioctl(
if (copy_from_user(&dmi, arg, sizeof(dmi)))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
+
error = xfs_set_dmattrs(ip, dmi.fsd_dmevmask,
dmi.fsd_dmstate);
+ mnt_drop_write_file(filp);
return -error;
}
@@ -1431,7 +1459,11 @@ xfs_file_ioctl(
if (copy_from_user(&sxp, arg, sizeof(xfs_swapext_t)))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
error = xfs_swapext(&sxp);
+ mnt_drop_write_file(filp);
return -error;
}
@@ -1460,9 +1492,14 @@ xfs_file_ioctl(
if (copy_from_user(&inout, arg, sizeof(inout)))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
+
/* input parameter is passed in resblks field of structure */
in = inout.resblks;
error = xfs_reserve_blocks(mp, &in, &inout);
+ mnt_drop_write_file(filp);
if (error)
return -error;
@@ -1493,7 +1530,11 @@ xfs_file_ioctl(
if (copy_from_user(&in, arg, sizeof(in)))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
error = xfs_growfs_data(mp, &in);
+ mnt_drop_write_file(filp);
return -error;
}
@@ -1503,7 +1544,11 @@ xfs_file_ioctl(
if (copy_from_user(&in, arg, sizeof(in)))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
error = xfs_growfs_log(mp, &in);
+ mnt_drop_write_file(filp);
return -error;
}
@@ -1513,7 +1558,11 @@ xfs_file_ioctl(
if (copy_from_user(&in, arg, sizeof(in)))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
error = xfs_growfs_rt(mp, &in);
+ mnt_drop_write_file(filp);
return -error;
}
diff --git a/fs/xfs/xfs_ioctl32.c b/fs/xfs/xfs_ioctl32.c
index f9ccb7b..2012369 100644
--- a/fs/xfs/xfs_ioctl32.c
+++ b/fs/xfs/xfs_ioctl32.c
@@ -602,7 +602,11 @@ xfs_file_compat_ioctl(
if (xfs_compat_growfs_data_copyin(&in, arg))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
error = xfs_growfs_data(mp, &in);
+ mnt_drop_write_file(filp);
return -error;
}
case XFS_IOC_FSGROWFSRT_32: {
@@ -610,7 +614,11 @@ xfs_file_compat_ioctl(
if (xfs_compat_growfs_rt_copyin(&in, arg))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
error = xfs_growfs_rt(mp, &in);
+ mnt_drop_write_file(filp);
return -error;
}
#endif
@@ -629,7 +637,11 @@ xfs_file_compat_ioctl(
offsetof(struct xfs_swapext, sx_stat)) ||
xfs_ioctl32_bstat_copyin(&sxp.sx_stat, &sxu->sx_stat))
return -XFS_ERROR(EFAULT);
+ error = mnt_want_write_file(filp);
+ if (error)
+ return error;
error = xfs_swapext(&sxp);
+ mnt_drop_write_file(filp);
return -error;
}
case XFS_IOC_FSBULKSTAT_32:
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 246c7d5..7ab98d9 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -679,7 +679,6 @@ xfs_iomap_write_unwritten(
* the same inode that we complete here and might deadlock
* on the iolock.
*/
- xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
tp = _xfs_trans_alloc(mp, XFS_TRANS_STRAT_WRITE, KM_NOFS);
tp->t_flags |= XFS_TRANS_RESERVE;
error = xfs_trans_reserve(tp, resblks,
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index d06afbc..bead529 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -1541,7 +1541,7 @@ xfs_unmountfs(
int
xfs_fs_writable(xfs_mount_t *mp)
{
- return !(xfs_test_for_freeze(mp) || XFS_FORCED_SHUTDOWN(mp) ||
+ return !(mp->m_super->s_writers.frozen || XFS_FORCED_SHUTDOWN(mp) ||
(mp->m_flags & XFS_MOUNT_RDONLY));
}
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 19f69e2..f0afeb9 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -310,9 +310,6 @@ void xfs_do_force_shutdown(struct xfs_mount *mp, int flags, char *fname,
#define SHUTDOWN_REMOTE_REQ 0x0010 /* shutdown came from remote cell */
#define SHUTDOWN_DEVICE_REQ 0x0020 /* failed all paths to the device */
-#define xfs_test_for_freeze(mp) ((mp)->m_super->s_frozen)
-#define xfs_wait_for_freeze(mp,l) vfs_check_frozen((mp)->m_super, (l))
-
/*
* Flags for xfs_mountfs
*/
diff --git a/fs/xfs/xfs_sync.c b/fs/xfs/xfs_sync.c
index 40b75ee..c44d687 100644
--- a/fs/xfs/xfs_sync.c
+++ b/fs/xfs/xfs_sync.c
@@ -498,7 +498,7 @@ xfs_sync_worker(
if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {
/* dgc: errors ignored here */
- if (mp->m_super->s_frozen == SB_UNFROZEN &&
+ if (mp->m_super->s_writers.frozen == SB_UNFROZEN &&
xfs_log_need_covered(mp))
error = xfs_fs_log_dummy(mp);
else
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index 329b06a..6468a2a 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -577,7 +577,6 @@ xfs_trans_alloc(
xfs_mount_t *mp,
uint type)
{
- xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
return _xfs_trans_alloc(mp, type, KM_SLEEP);
}
@@ -589,6 +588,7 @@ _xfs_trans_alloc(
{
xfs_trans_t *tp;
+ WARN_ON(mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
atomic_inc(&mp->m_active_trans);
tp = kmem_zone_zalloc(xfs_trans_zone, memflags);
--
1.7.1
--
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