diff options
| -rw-r--r-- | fs/xfs/xfs_bmap_util.c | 138 |
1 files changed, 73 insertions, 65 deletions
diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index e7d68318e6a5..d4ceba5370c7 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -597,8 +597,17 @@ out_unlock: * regular files that are marked preallocated or append-only. */ bool -xfs_can_free_eofblocks(struct xfs_inode *ip, bool force) +xfs_can_free_eofblocks( + struct xfs_inode *ip, + bool force) { + struct xfs_bmbt_irec imap; + struct xfs_mount *mp = ip->i_mount; + xfs_fileoff_t end_fsb; + xfs_fileoff_t last_fsb; + int nimaps = 1; + int error; + /* prealloc/delalloc exists only on regular files */ if (!S_ISREG(VFS_I(ip)->i_mode)) return false; @@ -624,7 +633,32 @@ xfs_can_free_eofblocks(struct xfs_inode *ip, bool force) if (!force || ip->i_delayed_blks == 0) return false; - return true; + /* + * Do not try to free post-EOF blocks if EOF is beyond the end of the + * range supported by the page cache, because the truncation will loop + * forever. + */ + end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip)); + last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); + if (last_fsb <= end_fsb) + return false; + + /* + * Look up the mapping for the first block past EOF. If we can't find + * it, there's nothing to free. + */ + xfs_ilock(ip, XFS_ILOCK_SHARED); + error = xfs_bmapi_read(ip, end_fsb, last_fsb - end_fsb, &imap, &nimaps, + 0); + xfs_iunlock(ip, XFS_ILOCK_SHARED); + if (error || nimaps == 0) + return false; + + /* + * If there's a real mapping there or there are delayed allocation + * reservations, then we have post-EOF blocks to try to free. + */ + return imap.br_startblock != HOLESTARTBLOCK || ip->i_delayed_blks; } /* @@ -637,78 +671,52 @@ xfs_free_eofblocks( struct xfs_inode *ip) { struct xfs_trans *tp; - int error; - xfs_fileoff_t end_fsb; - xfs_fileoff_t last_fsb; - xfs_filblks_t map_len; - int nimaps; - struct xfs_bmbt_irec imap; struct xfs_mount *mp = ip->i_mount; + int error; - /* - * Figure out if there are any blocks beyond the end - * of the file. If not, then there is nothing to do. - */ - end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip)); - last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes); - if (last_fsb <= end_fsb) - return 0; - map_len = last_fsb - end_fsb; + /* Attach the dquots to the inode up front. */ + error = xfs_qm_dqattach(ip); + if (error) + return error; - nimaps = 1; - xfs_ilock(ip, XFS_ILOCK_SHARED); - error = xfs_bmapi_read(ip, end_fsb, map_len, &imap, &nimaps, 0); - xfs_iunlock(ip, XFS_ILOCK_SHARED); + /* Wait on dio to ensure i_size has settled. */ + inode_dio_wait(VFS_I(ip)); - /* - * If there are blocks after the end of file, truncate the file to its - * current size to free them up. - */ - if (!error && (nimaps != 0) && - (imap.br_startblock != HOLESTARTBLOCK || - ip->i_delayed_blks)) { - /* - * Attach the dquots to the inode up front. - */ - error = xfs_qm_dqattach(ip); - if (error) - return error; + error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp); + if (error) { + ASSERT(XFS_FORCED_SHUTDOWN(mp)); + return error; + } - /* wait on dio to ensure i_size has settled */ - inode_dio_wait(VFS_I(ip)); + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, 0); - error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, - &tp); - if (error) { - ASSERT(XFS_FORCED_SHUTDOWN(mp)); - return error; - } + /* + * Do not update the on-disk file size. If we update the on-disk file + * size and then the system crashes before the contents of the file are + * flushed to disk then the files may be full of holes (ie NULL files + * bug). + */ + error = xfs_itruncate_extents_flags(&tp, ip, XFS_DATA_FORK, + XFS_ISIZE(ip), XFS_BMAPI_NODISCARD); + if (error) + goto err_cancel; - xfs_ilock(ip, XFS_ILOCK_EXCL); - xfs_trans_ijoin(tp, ip, 0); + error = xfs_trans_commit(tp); + if (error) + goto out_unlock; - /* - * Do not update the on-disk file size. If we update the - * on-disk file size and then the system crashes before the - * contents of the file are flushed to disk then the files - * may be full of holes (ie NULL files bug). - */ - error = xfs_itruncate_extents_flags(&tp, ip, XFS_DATA_FORK, - XFS_ISIZE(ip), XFS_BMAPI_NODISCARD); - if (error) { - /* - * If we get an error at this point we simply don't - * bother truncating the file. - */ - xfs_trans_cancel(tp); - } else { - error = xfs_trans_commit(tp); - if (!error) - xfs_inode_clear_eofblocks_tag(ip); - } + xfs_inode_clear_eofblocks_tag(ip); + goto out_unlock; - xfs_iunlock(ip, XFS_ILOCK_EXCL); - } +err_cancel: + /* + * If we get an error at this point we simply don't + * bother truncating the file. + */ + xfs_trans_cancel(tp); +out_unlock: + xfs_iunlock(ip, XFS_ILOCK_EXCL); return error; } |