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: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Alex Elder <aelder@sgi.com>
This commit is contained in:
Eric Sandeen 2010-02-05 22:59:53 +00:00 committed by Alex Elder
parent 388f1f0c34
commit d5db0f97fb
4 changed files with 64 additions and 25 deletions

View File

@ -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);

View File

@ -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,

View File

@ -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);
error = xfs_reserve_blocks(mp, &resblks, NULL);
if (error)
cmn_err(CE_WARN, "XFS: Unable to allocate reserve blocks. "
"Continuing without a reserve pool.");
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.");
}
return 0;

View File

@ -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 *);