Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 395d7341 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (33 commits)
  ext4: Regularize mount options
  ext4: fix locking typo in mballoc which could cause soft lockup hangs
  ext4: fix typo which causes a memory leak on error path
  jbd2: Update locking coments
  ext4: Rename pa_linear to pa_type
  ext4: add checks of block references for non-extent inodes
  ext4: Check for an valid i_mode when reading the inode from disk
  ext4: Use WRITE_SYNC for commits which are caused by fsync()
  ext4: Add auto_da_alloc mount option
  ext4: Use struct flex_groups to calculate get_orlov_stats()
  ext4: Use atomic_t's in struct flex_groups
  ext4: remove /proc tuning knobs
  ext4: Add sysfs support
  ext4: Track lifetime disk writes
  ext4: Fix discard of inode prealloc space with delayed allocation.
  ext4: Automatically allocate delay allocated blocks on rename
  ext4: Automatically allocate delay allocated blocks on close
  ext4: add EXT4_IOC_ALLOC_DA_BLKS ioctl
  ext4: Simplify delalloc code by removing mpage_da_writepages()
  ext4: Save stack space by removing fake buffer heads
  ...
parents c226fd65 06705bff

Documentation/ABI/testing/sysfs-fs-ext4

0 → 100644
+81 −0
Original line number Diff line number Diff line 
What:		/sys/fs/ext4/<disk>/mb_stats

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		 Controls whether the multiblock allocator should

		 collect statistics, which are shown during the unmount.

		 1 means to collect statistics, 0 means not to collect

		 statistics



What:		/sys/fs/ext4/<disk>/mb_group_prealloc

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		The multiblock allocator will round up allocation

		requests to a multiple of this tuning parameter if the

		stripe size is not set in the ext4 superblock



What:		/sys/fs/ext4/<disk>/mb_max_to_scan

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		The maximum number of extents the multiblock allocator

		will search to find the best extent



What:		/sys/fs/ext4/<disk>/mb_min_to_scan

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		The minimum number of extents the multiblock allocator

		will search to find the best extent



What:		/sys/fs/ext4/<disk>/mb_order2_req

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		Tuning parameter which controls the minimum size for 

		requests (as a power of 2) where the buddy cache is

		used



What:		/sys/fs/ext4/<disk>/mb_stream_req

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		Files which have fewer blocks than this tunable

		parameter will have their blocks allocated out of a

		block group specific preallocation pool, so that small

		files are packed closely together.  Each large file

		 will have its blocks allocated out of its own unique

		 preallocation pool.



What:		/sys/fs/ext4/<disk>/inode_readahead

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		Tuning parameter which controls the maximum number of

		inode table blocks that ext4's inode table readahead

		algorithm will pre-read into the buffer cache



What:		/sys/fs/ext4/<disk>/delayed_allocation_blocks

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		This file is read-only and shows the number of blocks

		that are dirty in the page cache, but which do not

		have their location in the filesystem allocated yet.



What:		/sys/fs/ext4/<disk>/lifetime_write_kbytes

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		This file is read-only and shows the number of kilobytes

		of data that have been written to this filesystem since it was

		created.



What:		/sys/fs/ext4/<disk>/session_write_kbytes

Date:		March 2008

Contact:	"Theodore Ts'o" <tytso@mit.edu>

Description:

		This file is read-only and shows the number of

		kilobytes of data that have been written to this

		filesystem since it was mounted.

Documentation/filesystems/ext4.txt

+27 −3
Original line number Diff line number Diff line
@@ -85,7 +85,7 @@ Note: More extensive information for getting started with ext4 can be 
* extent format more robust in face of on-disk corruption due to magics,

* internal redundancy in tree

* improved file allocation (multi-block alloc)

* fix 32000 subdirectory limit

* lift 32000 subdirectory limit imposed by i_links_count[1]

* nsec timestamps for mtime, atime, ctime, create time

* inode version field on disk (NFSv4, Lustre)

* reduced e2fsck time via uninit_bg feature
@@ -100,6 +100,9 @@ Note: More extensive information for getting started with ext4 can be 
* efficent new ordered mode in JBD2 and ext4(avoid using buffer head to force

  the ordering)



[1] Filesystems with a block size of 1k may see a limit imposed by the

directory hash tree having a maximum depth of two.



2.2 Candidate features for future inclusion



* Online defrag (patches available but not well tested)
@@ -180,8 +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
@@ -189,6 +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
@@ -310,6 +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:

Documentation/filesystems/proc.txt

+0 −21
Original line number Diff line number Diff line
@@ -940,27 +940,6 @@ Table 1-10: Files in /proc/fs/ext4/<devname> 
 File            Content                                        

 mb_groups       details of multiblock allocator buddy cache of free blocks

 mb_history      multiblock allocation history

 stats           controls whether the multiblock allocator should start

                 collecting statistics, which are shown during the unmount

 group_prealloc  the multiblock allocator will round up allocation

                 requests to a multiple of this tuning parameter if the

                 stripe size is not set in the ext4 superblock

 max_to_scan     The maximum number of extents the multiblock allocator

                 will search to find the best extent

 min_to_scan     The minimum number of extents the multiblock allocator

                 will search to find the best extent

 order2_req      Tuning parameter which controls the minimum size for 

                 requests (as a power of 2) where the buddy cache is

                 used

 stream_req      Files which have fewer blocks than this tunable

                 parameter will have their blocks allocated out of a

                 block group specific preallocation pool, so that small

                 files are packed closely together.  Each large file

                 will have its blocks allocated out of its own unique

                 preallocation pool.

inode_readahead  Tuning parameter which controls the maximum number of

                 inode table blocks that ext4's inode table readahead

                 algorithm will pre-read into the buffer cache

..............................................................................

fs/ext4/balloc.c

+5 −9
Original line number Diff line number Diff line
@@ -55,7 +55,8 @@ static int ext4_block_in_group(struct super_block *sb, ext4_fsblk_t block, 
}



static int ext4_group_used_meta_blocks(struct super_block *sb,

				ext4_group_t block_group)

				       ext4_group_t block_group,

				       struct ext4_group_desc *gdp)

{

	ext4_fsblk_t tmp;

	struct ext4_sb_info *sbi = EXT4_SB(sb);
@@ -63,10 +64,6 @@ static int ext4_group_used_meta_blocks(struct super_block *sb, 
	int used_blocks = sbi->s_itb_per_group + 2;



	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) {

		struct ext4_group_desc *gdp;

		struct buffer_head *bh;



		gdp = ext4_get_group_desc(sb, block_group, &bh);

		if (!ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp),

					block_group))

			used_blocks--;
@@ -177,7 +174,7 @@ unsigned ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, 
		 */

		mark_bitmap_end(group_blocks, sb->s_blocksize * 8, bh->b_data);

	}

	return free_blocks - ext4_group_used_meta_blocks(sb, block_group);

	return free_blocks - ext4_group_used_meta_blocks(sb, block_group, gdp);

}
@@ -473,9 +470,8 @@ void ext4_add_groupblocks(handle_t *handle, struct super_block *sb, 


	if (sbi->s_log_groups_per_flex) {

		ext4_group_t flex_group = ext4_flex_group(sbi, block_group);

		spin_lock(sb_bgl_lock(sbi, flex_group));

		sbi->s_flex_groups[flex_group].free_blocks += blocks_freed;

		spin_unlock(sb_bgl_lock(sbi, flex_group));

		atomic_add(blocks_freed,

			   &sbi->s_flex_groups[flex_group].free_blocks);

	}

	/*

	 * request to reload the buddy with the

fs/ext4/dir.c

+10 −6
Original line number Diff line number Diff line
@@ -67,7 +67,8 @@ int ext4_check_dir_entry(const char *function, struct inode *dir, 
			 unsigned int offset)

{

	const char *error_msg = NULL;

	const int rlen = ext4_rec_len_from_disk(de->rec_len);

	const int rlen = ext4_rec_len_from_disk(de->rec_len,

						dir->i_sb->s_blocksize);



	if (rlen < EXT4_DIR_REC_LEN(1))

		error_msg = "rec_len is smaller than minimal";
@@ -178,10 +179,11 @@ static int ext4_readdir(struct file *filp, 
				 * least that it is non-zero.  A

				 * failure will be detected in the

				 * dirent test below. */

				if (ext4_rec_len_from_disk(de->rec_len)

						< EXT4_DIR_REC_LEN(1))

				if (ext4_rec_len_from_disk(de->rec_len,

					sb->s_blocksize) < EXT4_DIR_REC_LEN(1))

					break;

				i += ext4_rec_len_from_disk(de->rec_len);

				i += ext4_rec_len_from_disk(de->rec_len,

							    sb->s_blocksize);

			}

			offset = i;

			filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1))
@@ -203,7 +205,8 @@ static int ext4_readdir(struct file *filp, 
				ret = stored;

				goto out;

			}

			offset += ext4_rec_len_from_disk(de->rec_len);

			offset += ext4_rec_len_from_disk(de->rec_len,

					sb->s_blocksize);

			if (le32_to_cpu(de->inode)) {

				/* We might block in the next section

				 * if the data destination is
@@ -225,7 +228,8 @@ static int ext4_readdir(struct file *filp, 
					goto revalidate;

				stored++;

			}

			filp->f_pos += ext4_rec_len_from_disk(de->rec_len);

			filp->f_pos += ext4_rec_len_from_disk(de->rec_len,

						sb->s_blocksize);

		}

		offset = 0;

		brelse(bh);