Documentation/ABI/testing/sysfs-fs-ext4

Source file repositories/reference/linux-study-clean/Documentation/ABI/testing/sysfs-fs-ext4

File Facts

System
Linux kernel
Corpus path
Documentation/ABI/testing/sysfs-fs-ext4
Extension
[no extension]
Size
4013 bytes
Lines
119
Domain
Support Tooling And Documentation
Bucket
Documentation
Inferred role
Support Tooling And Documentation: Documentation
Status
atlas-only

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

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_blks
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:

Annotation

Implementation Notes