diff options
Diffstat (limited to 'fs/xfs/xfs_trans.c')
-rw-r--r-- | fs/xfs/xfs_trans.c | 51 |
1 files changed, 30 insertions, 21 deletions
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c index 70f42ea..2011620 100644 --- a/fs/xfs/xfs_trans.c +++ b/fs/xfs/xfs_trans.c @@ -134,7 +134,7 @@ xfs_trans_reserve( bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0; /* Mark this thread as being in a transaction */ - current_set_flags_nested(&tp->t_pflags, PF_FSTRANS); + current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); /* * Attempt to reserve the needed disk blocks by decrementing @@ -144,7 +144,7 @@ xfs_trans_reserve( if (blocks > 0) { error = xfs_mod_fdblocks(tp->t_mountp, -((int64_t)blocks), rsvd); if (error != 0) { - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); return -ENOSPC; } tp->t_blk_res += blocks; @@ -221,7 +221,7 @@ undo_blocks: tp->t_blk_res = 0; } - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); return error; } @@ -263,6 +263,28 @@ xfs_trans_alloc( } /* + * Create an empty transaction with no reservation. This is a defensive + * mechanism for routines that query metadata without actually modifying + * them -- if the metadata being queried is somehow cross-linked (think a + * btree block pointer that points higher in the tree), we risk deadlock. + * However, blocks grabbed as part of a transaction can be re-grabbed. + * The verifiers will notice the corrupt block and the operation will fail + * back to userspace without deadlocking. + * + * Note the zero-length reservation; this transaction MUST be cancelled + * without any dirty data. + */ +int +xfs_trans_alloc_empty( + struct xfs_mount *mp, + struct xfs_trans **tpp) +{ + struct xfs_trans_res resv = {0}; + + return xfs_trans_alloc(mp, &resv, 0, 0, XFS_TRANS_NO_WRITECOUNT, tpp); +} + +/* * Record the indicated change to the given field for application * to the file system's superblock when the transaction commits. * For now, just store the change in the transaction structure. @@ -914,7 +936,7 @@ __xfs_trans_commit( xfs_log_commit_cil(mp, tp, &commit_lsn, regrant); - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); xfs_trans_free(tp); /* @@ -944,7 +966,7 @@ out_unreserve: if (commit_lsn == -1 && !error) error = -EIO; } - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); xfs_trans_free_items(tp, NULLCOMMITLSN, !!error); xfs_trans_free(tp); @@ -998,7 +1020,7 @@ xfs_trans_cancel( xfs_log_done(mp, tp->t_ticket, NULL, false); /* mark this thread as no longer being in a transaction */ - current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS); + current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS); xfs_trans_free_items(tp, NULLCOMMITLSN, dirty); xfs_trans_free(tp); @@ -1012,17 +1034,14 @@ xfs_trans_cancel( * chunk we've been working on and get a new transaction to continue. */ int -__xfs_trans_roll( +xfs_trans_roll( struct xfs_trans **tpp, - struct xfs_inode *dp, - int *committed) + struct xfs_inode *dp) { struct xfs_trans *trans; struct xfs_trans_res tres; int error; - *committed = 0; - /* * Ensure that the inode is always logged. */ @@ -1048,7 +1067,6 @@ __xfs_trans_roll( if (error) return error; - *committed = 1; trans = *tpp; /* @@ -1071,12 +1089,3 @@ __xfs_trans_roll( xfs_trans_ijoin(trans, dp, 0); return 0; } - -int -xfs_trans_roll( - struct xfs_trans **tpp, - struct xfs_inode *dp) -{ - int committed; - return __xfs_trans_roll(tpp, dp, &committed); -} |