Commit d5db0f97 authored by Eric Sandeen's avatar Eric Sandeen Committed by Alex Elder
Browse files

xfs: more reserved blocks fixups 



This mangles the reserved blocks counts a little more.

1) add a helper function for the default reserved count
2) add helper functions to save/restore counts on ro/rw
3) save/restore reserved blocks on freeze/thaw
4) disallow changing reserved count while readonly

V2: changed field name to match Dave's changes

Signed-off-by: default avatarEric Sandeen <sandeen@sandeen.net>
Signed-off-by: default avatarAlex Elder <aelder@sgi.com>
parent 388f1f0c

fs/xfs/linux-2.6/xfs_ioctl.c

+3 −0
Original line number Diff line number Diff line
@@ -1431,6 +1431,9 @@ xfs_file_ioctl( 
		if (!capable(CAP_SYS_ADMIN))

			return -EPERM;



		if (mp->m_flags & XFS_MOUNT_RDONLY)

			return -XFS_ERROR(EROFS);



		if (copy_from_user(&inout, arg, sizeof(inout)))

			return -XFS_ERROR(EFAULT);

fs/xfs/linux-2.6/xfs_super.c

+37 −14
Original line number Diff line number Diff line
@@ -1256,6 +1256,29 @@ xfs_fs_statfs( 
	return 0;

}



STATIC void

xfs_save_resvblks(struct xfs_mount *mp)

{

	__uint64_t resblks = 0;



	mp->m_resblks_save = mp->m_resblks;

	xfs_reserve_blocks(mp, &resblks, NULL);

}



STATIC void

xfs_restore_resvblks(struct xfs_mount *mp)

{

	__uint64_t resblks;



	if (mp->m_resblks_save) {

		resblks = mp->m_resblks_save;

		mp->m_resblks_save = 0;

	} else

		resblks = xfs_default_resblks(mp);



	xfs_reserve_blocks(mp, &resblks, NULL);

}



STATIC int

xfs_fs_remount(

	struct super_block	*sb,
@@ -1318,8 +1341,6 @@ xfs_fs_remount( 


	/* ro -> rw */

	if ((mp->m_flags & XFS_MOUNT_RDONLY) && !(*flags & MS_RDONLY)) {

		__uint64_t resblks;



		mp->m_flags &= ~XFS_MOUNT_RDONLY;

		if (mp->m_flags & XFS_MOUNT_BARRIER)

			xfs_mountfs_check_barriers(mp);
@@ -1342,15 +1363,7 @@ xfs_fs_remount( 
		 * Fill out the reserve pool if it is empty. Use the stashed

		 * value if it is non-zero, otherwise go with the default.

		 */

		if (mp->m_resblks_save) {

			resblks = mp->m_resblks_save;

			mp->m_resblks_save = 0;

		} else {

			resblks = mp->m_sb.sb_dblocks;

			do_div(resblks, 20);

			resblks = min_t(__uint64_t, resblks, 1024);

		}

		xfs_reserve_blocks(mp, &resblks, NULL);

		xfs_restore_resvblks(mp);

	}



	/* rw -> ro */
@@ -1363,11 +1376,9 @@ xfs_fs_remount( 
		 * so that if we get remounted rw, we can return it to the same

		 * size.

		 */

		__uint64_t resblks = 0;



		xfs_quiesce_data(mp);

		mp->m_resblks_save = mp->m_resblks;

		xfs_reserve_blocks(mp, &resblks, NULL);

		xfs_save_resvblks(mp);

		xfs_quiesce_attr(mp);

		mp->m_flags |= XFS_MOUNT_RDONLY;

	}
@@ -1386,10 +1397,21 @@ xfs_fs_freeze( 
{

	struct xfs_mount	*mp = XFS_M(sb);



	xfs_save_resvblks(mp);

	xfs_quiesce_attr(mp);

	return -xfs_fs_log_dummy(mp);

}



STATIC int

xfs_fs_unfreeze(

	struct super_block	*sb)

{

	struct xfs_mount	*mp = XFS_M(sb);



	xfs_restore_resvblks(mp);

	return 0;

}



STATIC int

xfs_fs_show_options(

	struct seq_file		*m,
@@ -1612,6 +1634,7 @@ static const struct super_operations xfs_super_operations = { 
	.put_super		= xfs_fs_put_super,

	.sync_fs		= xfs_fs_sync_fs,

	.freeze_fs		= xfs_fs_freeze,

	.unfreeze_fs		= xfs_fs_unfreeze,

	.statfs			= xfs_fs_statfs,

	.remount_fs		= xfs_fs_remount,

	.show_options		= xfs_fs_show_options,

fs/xfs/xfs_mount.c

+23 −11
Original line number Diff line number Diff line
@@ -1091,6 +1091,22 @@ xfs_mount_reset_sbqflags( 
	return xfs_trans_commit(tp, 0);

}



__uint64_t

xfs_default_resblks(xfs_mount_t *mp)

{

	__uint64_t resblks;



	/*

	 * We default to 5% or 1024 fsbs of space reserved, whichever is smaller.

	 * This may drive us straight to ENOSPC on mount, but that implies

	 * we were already there on the last unmount. Warn if this occurs.

	 */

	resblks = mp->m_sb.sb_dblocks;

	do_div(resblks, 20);

	resblks = min_t(__uint64_t, resblks, 1024);

	return resblks;

}



/*

 * This function does the following on an initial mount of a file system:

 *	- reads the superblock from disk and init the mount struct
@@ -1401,18 +1417,14 @@ xfs_mountfs( 
	 * when at ENOSPC. This is needed for operations like create with

	 * attr, unwritten extent conversion at ENOSPC, etc. Data allocations

	 * are not allowed to use this reserved space.

	 *

	 * We default to 5% or 1024 fsbs of space reserved, whichever is smaller.

	 * This may drive us straight to ENOSPC on mount, but that implies

	 * we were already there on the last unmount. Warn if this occurs.

	 */

	resblks = mp->m_sb.sb_dblocks;

	do_div(resblks, 20);

	resblks = min_t(__uint64_t, resblks, 1024);

	if (!(mp->m_flags & XFS_MOUNT_RDONLY)) {

		resblks = xfs_default_resblks(mp);

		error = xfs_reserve_blocks(mp, &resblks, NULL);

		if (error)

		cmn_err(CE_WARN, "XFS: Unable to allocate reserve blocks. "

				"Continuing without a reserve pool.");

			cmn_err(CE_WARN, "XFS: Unable to allocate reserve "

				"blocks. Continuing without a reserve pool.");

	}



	return 0;

fs/xfs/xfs_mount.h

+1 −0
Original line number Diff line number Diff line
@@ -421,6 +421,7 @@ typedef struct xfs_mod_sb { 
} xfs_mod_sb_t;



extern int	xfs_log_sbcount(xfs_mount_t *, uint);

extern __uint64_t xfs_default_resblks(xfs_mount_t *mp);

extern int	xfs_mountfs(xfs_mount_t *mp);



extern void	xfs_unmountfs(xfs_mount_t *);

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