diff options
| -rw-r--r-- | Documentation/filesystems/ext4.txt | 25 | ||||
| -rw-r--r-- | fs/ext4/super.c | 30 |
2 files changed, 45 insertions, 10 deletions
diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt index 5c484aec2ba..97882df0486 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -183,8 +183,8 @@ commit=nrsec (*) Ext4 can be told to sync all its data and metadata performance. barrier=<0|1(*)> This enables/disables the use of write barriers in - the jbd code. barrier=0 disables, barrier=1 enables. - This also requires an IO stack which can support +barrier(*) the jbd code. barrier=0 disables, barrier=1 enables. +nobarrier This also requires an IO stack which can support barriers, and if jbd gets an error on a barrier write, it will disable again with a warning. Write barriers enforce proper on-disk ordering @@ -192,6 +192,9 @@ barrier=<0|1(*)> This enables/disables the use of write barriers in safe to use, at some performance penalty. If your disks are battery-backed in one way or another, disabling barriers may safely improve performance. + The mount options "barrier" and "nobarrier" can + also be used to enable or disable barriers, for + consistency with other ext4 mount options. inode_readahead=n This tuning parameter controls the maximum number of inode table blocks that ext4's inode @@ -313,6 +316,24 @@ journal_ioprio=prio The I/O priority (from 0 to 7, where 0 is the a slightly higher priority than the default I/O priority. +auto_da_alloc(*) Many broken applications don't use fsync() when +noauto_da_alloc replacing existing files via patterns such as + fd = open("foo.new")/write(fd,..)/close(fd)/ + rename("foo.new", "foo"), or worse yet, + fd = open("foo", O_TRUNC)/write(fd,..)/close(fd). + If auto_da_alloc is enabled, ext4 will detect + the replace-via-rename and replace-via-truncate + patterns and force that any delayed allocation + blocks are allocated such that at the next + journal commit, in the default data=ordered + mode, the data blocks of the new file are forced + to disk before the rename() operation is + commited. This provides roughly the same level + of guarantees as ext3, and avoids the + "zero-length" problem that can happen when a + system crashes before the delayed allocation + blocks are forced to disk. + Data Mode ========= There are 3 different data modes: diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 45d07cf9df3..9987bba99db 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -867,7 +867,7 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs) seq_puts(seq, ",data_err=abort"); if (test_opt(sb, NO_AUTO_DA_ALLOC)) - seq_puts(seq, ",auto_da_alloc=0"); + seq_puts(seq, ",noauto_da_alloc"); ext4_show_quota_options(seq, sb); return 0; @@ -1018,7 +1018,7 @@ enum { Opt_resgid, Opt_resuid, Opt_sb, Opt_err_cont, Opt_err_panic, Opt_err_ro, Opt_nouid32, Opt_debug, Opt_oldalloc, Opt_orlov, Opt_user_xattr, Opt_nouser_xattr, Opt_acl, Opt_noacl, - Opt_auto_da_alloc, Opt_noload, Opt_nobh, Opt_bh, + Opt_auto_da_alloc, Opt_noauto_da_alloc, Opt_noload, Opt_nobh, Opt_bh, Opt_commit, Opt_min_batch_time, Opt_max_batch_time, Opt_journal_update, Opt_journal_dev, Opt_journal_checksum, Opt_journal_async_commit, @@ -1026,8 +1026,8 @@ enum { Opt_data_err_abort, Opt_data_err_ignore, Opt_usrjquota, Opt_grpjquota, Opt_offusrjquota, Opt_offgrpjquota, Opt_jqfmt_vfsold, Opt_jqfmt_vfsv0, Opt_quota, Opt_noquota, - Opt_ignore, Opt_barrier, Opt_err, Opt_resize, Opt_usrquota, - Opt_grpquota, Opt_i_version, + Opt_ignore, Opt_barrier, Opt_nobarrier, Opt_err, Opt_resize, + Opt_usrquota, Opt_grpquota, Opt_i_version, Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_inode_readahead_blks, Opt_journal_ioprio }; @@ -1080,6 +1080,8 @@ static const match_table_t tokens = { {Opt_quota, "quota"}, {Opt_usrquota, "usrquota"}, {Opt_barrier, "barrier=%u"}, + {Opt_barrier, "barrier"}, + {Opt_nobarrier, "nobarrier"}, {Opt_i_version, "i_version"}, {Opt_stripe, "stripe=%u"}, {Opt_resize, "resize"}, @@ -1088,6 +1090,8 @@ static const match_table_t tokens = { {Opt_inode_readahead_blks, "inode_readahead_blks=%u"}, {Opt_journal_ioprio, "journal_ioprio=%u"}, {Opt_auto_da_alloc, "auto_da_alloc=%u"}, + {Opt_auto_da_alloc, "auto_da_alloc"}, + {Opt_noauto_da_alloc, "noauto_da_alloc"}, {Opt_err, NULL}, }; @@ -1422,9 +1426,14 @@ set_qf_format: case Opt_abort: set_opt(sbi->s_mount_opt, ABORT); break; + case Opt_nobarrier: + clear_opt(sbi->s_mount_opt, BARRIER); + break; case Opt_barrier: - if (match_int(&args[0], &option)) - return 0; + if (match_int(&args[0], &option)) { + set_opt(sbi->s_mount_opt, BARRIER); + break; + } if (option) set_opt(sbi->s_mount_opt, BARRIER); else @@ -1485,9 +1494,14 @@ set_qf_format: *journal_ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, option); break; + case Opt_noauto_da_alloc: + set_opt(sbi->s_mount_opt,NO_AUTO_DA_ALLOC); + break; case Opt_auto_da_alloc: - if (match_int(&args[0], &option)) - return 0; + if (match_int(&args[0], &option)) { + clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC); + break; + } if (option) clear_opt(sbi->s_mount_opt, NO_AUTO_DA_ALLOC); else |