From 0390131ba84fd3f726f9e24fc4553828125700bb Mon Sep 17 00:00:00 2001 From: Frank Mayhar Date: Wed, 7 Jan 2009 00:06:22 -0500 Subject: ext4: Allow ext4 to run without a journal A few weeks ago I posted a patch for discussion that allowed ext4 to run without a journal. Since that time I've integrated the excellent comments from Andreas and fixed several serious bugs. We're currently running with this patch and generating some performance numbers against both ext2 (with backported reservations code) and ext4 with and without a journal. It just so happens that running without a journal is slightly faster for most everything. We did iozone -T -t 4 s 2g -r 256k -T -I -i0 -i1 -i2 which creates 4 threads, each of which create and do reads and writes on a 2G file, with a buffer size of 256K, using O_DIRECT for all file opens to bypass the page cache. Results: ext2 ext4, default ext4, no journal initial writes 13.0 MB/s 15.4 MB/s 15.7 MB/s rewrites 13.1 MB/s 15.6 MB/s 15.9 MB/s reads 15.2 MB/s 16.9 MB/s 17.2 MB/s re-reads 15.3 MB/s 16.9 MB/s 17.2 MB/s random readers 5.6 MB/s 5.6 MB/s 5.7 MB/s random writers 5.1 MB/s 5.3 MB/s 5.4 MB/s So it seems that, so far, this was a useful exercise. Signed-off-by: Frank Mayhar Signed-off-by: "Theodore Ts'o" --- fs/ext4/migrate.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'fs/ext4/migrate.c') diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c index f2a9cf498ec..e7cd488da4b 100644 --- a/fs/ext4/migrate.c +++ b/fs/ext4/migrate.c @@ -59,7 +59,8 @@ static int finish_range(handle_t *handle, struct inode *inode, /* * Make sure the credit we accumalated is not really high */ - if (needed && handle->h_buffer_credits >= EXT4_RESERVE_TRANS_BLOCKS) { + if (needed && ext4_handle_has_enough_credits(handle, + EXT4_RESERVE_TRANS_BLOCKS)) { retval = ext4_journal_restart(handle, needed); if (retval) goto err_out; @@ -229,7 +230,7 @@ static int extend_credit_for_blkdel(handle_t *handle, struct inode *inode) { int retval = 0, needed; - if (handle->h_buffer_credits > EXT4_RESERVE_TRANS_BLOCKS) + if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1)) return 0; /* * We are freeing a blocks. During this we touch -- cgit v1.2.3-70-g09d2 From 83982b6f47201c4c7767210d24d7d8c99567a0b3 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Tue, 6 Jan 2009 14:53:16 -0500 Subject: ext4: Remove "extents" mount option This mount option is largely superfluous, and in fact the way it was implemented was buggy; if a filesystem which did not have the extents feature flag was mounted -o extents, the filesystem would attempt to create and use extents-based file even though the extents feature flag was not eabled. The simplest thing to do is to nuke the mount option entirely. It's not all that useful to force the non-creation of new extent-based files if the filesystem can support it. Signed-off-by: "Theodore Ts'o" --- Documentation/filesystems/ext4.txt | 5 ---- fs/ext4/ext4.h | 1 - fs/ext4/ext4_jbd2.h | 4 ++-- fs/ext4/extents.c | 4 ++-- fs/ext4/ialloc.c | 2 +- fs/ext4/migrate.c | 14 +++++------ fs/ext4/super.c | 48 ++------------------------------------ 7 files changed, 14 insertions(+), 64 deletions(-) (limited to 'fs/ext4/migrate.c') diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt index 8938949b201..cec829bc729 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -131,11 +131,6 @@ ro Mount filesystem read only. Note that ext4 will mount options "ro,noload" can be used to prevent writes to the filesystem. -extents (*) ext4 will use extents to address file data. The - file system will no longer be mountable by ext3. - -noextents ext4 will not use extents for newly created files - journal_checksum Enable checksumming of the journal transactions. This will allow the recovery code in e2fsck and the kernel to detect corruption in the kernel. It is a diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 695b45cc34e..db1718833f5 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -536,7 +536,6 @@ do { \ #define EXT4_MOUNT_QUOTA 0x80000 /* Some quota option set */ #define EXT4_MOUNT_USRQUOTA 0x100000 /* "old" user quota */ #define EXT4_MOUNT_GRPQUOTA 0x200000 /* "old" group quota */ -#define EXT4_MOUNT_EXTENTS 0x400000 /* Extents support */ #define EXT4_MOUNT_JOURNAL_CHECKSUM 0x800000 /* Journal checksums */ #define EXT4_MOUNT_JOURNAL_ASYNC_COMMIT 0x1000000 /* Journal Async Commit */ #define EXT4_MOUNT_I_VERSION 0x2000000 /* i_version support */ diff --git a/fs/ext4/ext4_jbd2.h b/fs/ext4/ext4_jbd2.h index 663197adae5..be2f426f680 100644 --- a/fs/ext4/ext4_jbd2.h +++ b/fs/ext4/ext4_jbd2.h @@ -32,8 +32,8 @@ * 5 levels of tree + root which are stored in the inode. */ #define EXT4_SINGLEDATA_TRANS_BLOCKS(sb) \ - (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS) \ - || test_opt(sb, EXTENTS) ? 27U : 8U) + (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS) \ + ? 27U : 8U) /* Extended attribute operations touch at most two data buffers, * two bitmap buffers, and two group summaries, in addition to the inode diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index c64080e4949..240cf0daad4 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2247,7 +2247,7 @@ void ext4_ext_init(struct super_block *sb) * possible initialization would be here */ - if (test_opt(sb, EXTENTS)) { + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) { printk(KERN_INFO "EXT4-fs: file extents enabled"); #ifdef AGGRESSIVE_TEST printk(", aggressive tests"); @@ -2272,7 +2272,7 @@ void ext4_ext_init(struct super_block *sb) */ void ext4_ext_release(struct super_block *sb) { - if (!test_opt(sb, EXTENTS)) + if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) return; #ifdef EXTENTS_STATS diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 369c34c6429..4fb86a0061d 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -917,7 +917,7 @@ got: if (err) goto fail_free_drop; - if (test_opt(sb, EXTENTS)) { + if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) { /* set extent flag only for directory, file and normal symlink*/ if (S_ISDIR(mode) || S_ISREG(mode) || S_ISLNK(mode)) { EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL; diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c index e7cd488da4b..734abca25e3 100644 --- a/fs/ext4/migrate.c +++ b/fs/ext4/migrate.c @@ -459,13 +459,13 @@ int ext4_ext_migrate(struct inode *inode) struct list_blocks_struct lb; unsigned long max_entries; - if (!test_opt(inode->i_sb, EXTENTS)) - /* - * if mounted with noextents we don't allow the migrate - */ - return -EINVAL; - - if ((EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) + /* + * If the filesystem does not support extents, or the inode + * already is extent-based, error out. + */ + if (!EXT4_HAS_INCOMPAT_FEATURE(inode->i_sb, + EXT4_FEATURE_INCOMPAT_EXTENTS) || + (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL)) return -EINVAL; if (S_ISLNK(inode->i_mode) && inode->i_blocks == 0) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index b69d0920386..acb69c00fd4 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -829,8 +829,6 @@ static int ext4_show_options(struct seq_file *seq, struct vfsmount *vfs) seq_puts(seq, ",journal_async_commit"); if (test_opt(sb, NOBH)) seq_puts(seq, ",nobh"); - if (!test_opt(sb, EXTENTS)) - seq_puts(seq, ",noextents"); if (test_opt(sb, I_VERSION)) seq_puts(seq, ",i_version"); if (!test_opt(sb, DELALLOC)) @@ -1011,7 +1009,7 @@ enum { 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_extents, Opt_noextents, Opt_i_version, + Opt_grpquota, Opt_i_version, Opt_stripe, Opt_delalloc, Opt_nodelalloc, Opt_inode_readahead_blks, Opt_journal_ioprio }; @@ -1066,8 +1064,6 @@ static const match_table_t tokens = { {Opt_quota, "quota"}, {Opt_usrquota, "usrquota"}, {Opt_barrier, "barrier=%u"}, - {Opt_extents, "extents"}, - {Opt_noextents, "noextents"}, {Opt_i_version, "i_version"}, {Opt_stripe, "stripe=%u"}, {Opt_resize, "resize"}, @@ -1115,7 +1111,6 @@ static int parse_options(char *options, struct super_block *sb, int qtype, qfmt; char *qname; #endif - ext4_fsblk_t last_block; if (!options) return 1; @@ -1445,33 +1440,6 @@ set_qf_format: case Opt_bh: clear_opt(sbi->s_mount_opt, NOBH); break; - case Opt_extents: - if (!EXT4_HAS_INCOMPAT_FEATURE(sb, - EXT4_FEATURE_INCOMPAT_EXTENTS)) { - ext4_warning(sb, __func__, - "extents feature not enabled " - "on this filesystem, use tune2fs"); - return 0; - } - set_opt(sbi->s_mount_opt, EXTENTS); - break; - case Opt_noextents: - /* - * When e2fsprogs support resizing an already existing - * ext3 file system to greater than 2**32 we need to - * add support to block allocator to handle growing - * already existing block mapped inode so that blocks - * allocated for them fall within 2**32 - */ - last_block = ext4_blocks_count(sbi->s_es) - 1; - if (last_block > 0xffffffffULL) { - printk(KERN_ERR "EXT4-fs: Filesystem too " - "large to mount with " - "-o noextents options\n"); - return 0; - } - clear_opt(sbi->s_mount_opt, EXTENTS); - break; case Opt_i_version: set_opt(sbi->s_mount_opt, I_VERSION); sb->s_flags |= MS_I_VERSION; @@ -2135,18 +2103,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) set_opt(sbi->s_mount_opt, RESERVATION); set_opt(sbi->s_mount_opt, BARRIER); - /* - * turn on extents feature by default in ext4 filesystem - * only if feature flag already set by mkfs or tune2fs. - * Use -o noextents to turn it off - */ - if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) - set_opt(sbi->s_mount_opt, EXTENTS); - else - ext4_warning(sb, __func__, - "extents feature not enabled on this filesystem, " - "use tune2fs."); - /* * enable delayed allocation by default * Use -o nodelalloc to turn it off @@ -3825,7 +3781,7 @@ static void __exit exit_ext4_fs(void) } MODULE_AUTHOR("Remy Card, Stephen Tweedie, Andrew Morton, Andreas Dilger, Theodore Ts'o and others"); -MODULE_DESCRIPTION("Fourth Extended Filesystem with extents"); +MODULE_DESCRIPTION("Fourth Extended Filesystem"); MODULE_LICENSE("GPL"); module_init(init_ext4_fs) module_exit(exit_ext4_fs) -- cgit v1.2.3-70-g09d2