xfs: Convert to new freezing code

Generic code now blocks all writers from standard write paths. So we add
blocking of all writers coming from ioctl (we get a protection of ioctl against
racing remount read-only as a bonus) and convert xfs_file_aio_write() to a
non-racy freeze protection. We also keep freeze protection on transaction
start to block internal filesystem writes such as removal of preallocated
blocks.

CC: Ben Myers <bpm@sgi.com>
CC: Alex Elder <elder@kernel.org>
CC: xfs@oss.sgi.com
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 52 insertions, 3 deletions

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index 1f1535d25a9b..0e0232c3b6d9 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -364,9 +364,15 @@ 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);
@@ -382,6 +388,7 @@ xfs_fssetdm_by_handle(
                                  fsd.fsd_dmstate);
 
  out:
+        mnt_drop_write_file(parfilp);
         dput(dentry);
         return error;
 }
@@ -634,7 +641,11 @@ 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;
 }
 
@@ -1163,6 +1174,7 @@ xfs_ioc_fssetxattr(
 {
         struct fsxattr          fa;
         unsigned int            mask;
+        int error;
 
         if (copy_from_user(&fa, arg, sizeof(fa)))
                 return -EFAULT;
@@ -1171,7 +1183,12 @@ 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
@@ -1196,6 +1213,7 @@ xfs_ioc_setxflags(
         struct fsxattr          fa;
         unsigned int            flags;
         unsigned int            mask;
+        int error;
 
         if (copy_from_user(&flags, arg, sizeof(flags)))
                 return -EFAULT;
@@ -1210,7 +1228,12 @@ 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
@@ -1385,8 +1408,13 @@ 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;
         }
 
@@ -1434,7 +1462,11 @@ 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;
         }
 
@@ -1463,9 +1495,14 @@ 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;
 
@@ -1496,7 +1533,11 @@ 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;
         }
 
@@ -1506,7 +1547,11 @@ 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;
         }
 
@@ -1516,7 +1561,11 @@ 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;
         }