diff options
| -rw-r--r-- | fs/xfs/xfs_trans.c | 77 |
1 files changed, 40 insertions, 37 deletions
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index 2caa0783049..356d6627f58 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -638,11 +638,23 @@ xfs_trans_apply_sb_deltas( } /* - * xfs_trans_unreserve_and_mod_sb() is called to release unused - * reservations and apply superblock counter changes to the in-core - * superblock. + * xfs_trans_unreserve_and_mod_sb() is called to release unused reservations + * and apply superblock counter changes to the in-core superblock. The + * t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT + * applied to the in-core superblock. The idea is that that has already been + * done. * * This is done efficiently with a single call to xfs_mod_incore_sb_batch(). + * However, we have to ensure that we only modify each superblock field only + * once because the application of the delta values may not be atomic. That can + * lead to ENOSPC races occurring if we have two separate modifcations of the + * free space counter to put back the entire reservation and then take away + * what we used. + * + * If we are not logging superblock counters, then the inode allocated/free and + * used block counts are not updated in the on disk superblock. In this case, + * XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we + * still need to update the incore superblock with the changes. */ STATIC void xfs_trans_unreserve_and_mod_sb( @@ -654,42 +666,43 @@ xfs_trans_unreserve_and_mod_sb( /* REFERENCED */ int error; int rsvd; + int64_t blkdelta = 0; + int64_t rtxdelta = 0; msbp = msb; rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0; - /* - * Release any reserved blocks. Any that were allocated - * will be taken back again by fdblocks_delta below. - */ - if (tp->t_blk_res > 0) { + /* calculate free blocks delta */ + if (tp->t_blk_res > 0) + blkdelta = tp->t_blk_res; + + if ((tp->t_fdblocks_delta != 0) && + (xfs_sb_version_haslazysbcount(&mp->m_sb) || + (tp->t_flags & XFS_TRANS_SB_DIRTY))) + blkdelta += tp->t_fdblocks_delta; + + if (blkdelta != 0) { msbp->msb_field = XFS_SBS_FDBLOCKS; - msbp->msb_delta = tp->t_blk_res; + msbp->msb_delta = blkdelta; msbp++; } - /* - * Release any reserved real time extents . Any that were - * allocated will be taken back again by frextents_delta below. - */ - if (tp->t_rtx_res > 0) { + /* calculate free realtime extents delta */ + if (tp->t_rtx_res > 0) + rtxdelta = tp->t_rtx_res; + + if ((tp->t_frextents_delta != 0) && + (tp->t_flags & XFS_TRANS_SB_DIRTY)) + rtxdelta += tp->t_frextents_delta; + + if (rtxdelta != 0) { msbp->msb_field = XFS_SBS_FREXTENTS; - msbp->msb_delta = tp->t_rtx_res; + msbp->msb_delta = rtxdelta; msbp++; } - /* - * Apply any superblock modifications to the in-core version. - * The t_res_fdblocks_delta and t_res_frextents_delta fields are - * explicitly NOT applied to the in-core superblock. - * The idea is that that has already been done. - * - * If we are not logging superblock counters, then the inode - * allocated/free and used block counts are not updated in the - * on disk superblock. In this case, XFS_TRANS_SB_DIRTY will - * not be set when the transaction is updated but we still need - * to update the incore superblock with the changes. - */ + /* apply remaining deltas */ + if (xfs_sb_version_haslazysbcount(&mp->m_sb) || (tp->t_flags & XFS_TRANS_SB_DIRTY)) { if (tp->t_icount_delta != 0) { @@ -702,19 +715,9 @@ xfs_trans_unreserve_and_mod_sb( msbp->msb_delta = tp->t_ifree_delta; msbp++; } - if (tp->t_fdblocks_delta != 0) { - msbp->msb_field = XFS_SBS_FDBLOCKS; - msbp->msb_delta = tp->t_fdblocks_delta; - msbp++; - } } if (tp->t_flags & XFS_TRANS_SB_DIRTY) { - if (tp->t_frextents_delta != 0) { - msbp->msb_field = XFS_SBS_FREXTENTS; - msbp->msb_delta = tp->t_frextents_delta; - msbp++; - } if (tp->t_dblocks_delta != 0) { msbp->msb_field = XFS_SBS_DBLOCKS; msbp->msb_delta = tp->t_dblocks_delta; |