diff options
Diffstat (limited to 'fs/xfs/xfs_fsops.c')
| -rw-r--r-- | fs/xfs/xfs_fsops.c | 60 |
1 files changed, 27 insertions, 33 deletions
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index 33e26690a8c4..68f74549fa22 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -17,6 +17,7 @@ #include "xfs_fsops.h" #include "xfs_trans_space.h" #include "xfs_log.h" +#include "xfs_log_priv.h" #include "xfs_ag.h" #include "xfs_ag_resv.h" #include "xfs_trace.h" @@ -347,7 +348,7 @@ xfs_fs_counts( cnt->allocino = percpu_counter_read_positive(&mp->m_icount); cnt->freeino = percpu_counter_read_positive(&mp->m_ifree); cnt->freedata = percpu_counter_read_positive(&mp->m_fdblocks) - - mp->m_alloc_set_aside; + xfs_fdblocks_unavailable(mp); spin_lock(&mp->m_sb_lock); cnt->freertx = mp->m_sb.sb_frextents; @@ -430,46 +431,36 @@ xfs_reserve_blocks( * If the request is larger than the current reservation, reserve the * blocks before we update the reserve counters. Sample m_fdblocks and * perform a partial reservation if the request exceeds free space. + * + * The code below estimates how many blocks it can request from + * fdblocks to stash in the reserve pool. This is a classic TOCTOU + * race since fdblocks updates are not always coordinated via + * m_sb_lock. Set the reserve size even if there's not enough free + * space to fill it because mod_fdblocks will refill an undersized + * reserve when it can. */ - error = -ENOSPC; - do { - free = percpu_counter_sum(&mp->m_fdblocks) - - mp->m_alloc_set_aside; - if (free <= 0) - break; - - delta = request - mp->m_resblks; - lcounter = free - delta; - if (lcounter < 0) - /* We can't satisfy the request, just get what we can */ - fdblks_delta = free; - else - fdblks_delta = delta; - + free = percpu_counter_sum(&mp->m_fdblocks) - + xfs_fdblocks_unavailable(mp); + delta = request - mp->m_resblks; + mp->m_resblks = request; + if (delta > 0 && free > 0) { /* * We'll either succeed in getting space from the free block - * count or we'll get an ENOSPC. If we get a ENOSPC, it means - * things changed while we were calculating fdblks_delta and so - * we should try again to see if there is anything left to - * reserve. + * count or we'll get an ENOSPC. Don't set the reserved flag + * here - we don't want to reserve the extra reserve blocks + * from the reserve. * - * Don't set the reserved flag here - we don't want to reserve - * the extra reserve blocks from the reserve..... + * The desired reserve size can change after we drop the lock. + * Use mod_fdblocks to put the space into the reserve or into + * fdblocks as appropriate. */ + fdblks_delta = min(free, delta); spin_unlock(&mp->m_sb_lock); error = xfs_mod_fdblocks(mp, -fdblks_delta, 0); + if (!error) + xfs_mod_fdblocks(mp, fdblks_delta, 0); spin_lock(&mp->m_sb_lock); - } while (error == -ENOSPC); - - /* - * Update the reserve counters if blocks have been successfully - * allocated. - */ - if (!error && fdblks_delta) { - mp->m_resblks += fdblks_delta; - mp->m_resblks_avail += fdblks_delta; } - out: if (outval) { outval->resblks = mp->m_resblks; @@ -528,8 +519,11 @@ xfs_do_force_shutdown( int tag; const char *why; - if (test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &mp->m_opstate)) + + if (test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &mp->m_opstate)) { + xlog_shutdown_wait(mp->m_log); return; + } if (mp->m_sb_bp) mp->m_sb_bp->b_flags |= XBF_DONE; |