ext4, doc: remove unnecessary escaping

Signed-off-by: Wang Jianjian <wangjianjian3@huawei.com>
Link: https://lore.kernel.org/r/20220520022255.2120576-2-wangjianjian3@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Documentation/filesystems/ext4/attributes.rst

@@ -13,8 +13,8 @@ disappeared as of Linux 3.0.
 
 There are two places where extended attributes can be found. The first
 place is between the end of each inode entry and the beginning of the
-next inode entry. For example, if inode.i\_extra\_isize = 28 and
-sb.inode\_size = 256, then there are 256 - (128 + 28) = 100 bytes
+next inode entry. For example, if inode.i_extra_isize = 28 and
+sb.inode_size = 256, then there are 256 - (128 + 28) = 100 bytes
 available for in-inode extended attribute storage. The second place
 where extended attributes can be found is in the block pointed to by
 ``inode.i_file_acl``. As of Linux 3.11, it is not possible for this
@@ -38,8 +38,8 @@ Extended attributes, when stored after the inode, have a header
      - Name
      - Description
    * - 0x0
-     - \_\_le32
-     - h\_magic
+     - __le32
+     - h_magic
      - Magic number for identification, 0xEA020000. This value is set by the
        Linux driver, though e2fsprogs doesn't seem to check it(?)
 
@@ -55,28 +55,28 @@ The beginning of an extended attribute block is in
      - Name
      - Description
    * - 0x0
-     - \_\_le32
-     - h\_magic
+     - __le32
+     - h_magic
      - Magic number for identification, 0xEA020000.
    * - 0x4
-     - \_\_le32
-     - h\_refcount
+     - __le32
+     - h_refcount
      - Reference count.
    * - 0x8
-     - \_\_le32
-     - h\_blocks
+     - __le32
+     - h_blocks
      - Number of disk blocks used.
    * - 0xC
-     - \_\_le32
-     - h\_hash
+     - __le32
+     - h_hash
      - Hash value of all attributes.
    * - 0x10
-     - \_\_le32
-     - h\_checksum
+     - __le32
+     - h_checksum
      - Checksum of the extended attribute block.
    * - 0x14
-     - \_\_u32
-     - h\_reserved[3]
+     - __u32
+     - h_reserved[3]
      - Zero.
 
 The checksum is calculated against the FS UUID, the 64-bit block number
@@ -100,46 +100,46 @@ Attributes stored inside an inode do not need be stored in sorted order.
      - Name
      - Description
    * - 0x0
-     - \_\_u8
-     - e\_name\_len
+     - __u8
+     - e_name_len
      - Length of name.
    * - 0x1
-     - \_\_u8
-     - e\_name\_index
+     - __u8
+     - e_name_index
      - Attribute name index. There is a discussion of this below.
    * - 0x2
-     - \_\_le16
-     - e\_value\_offs
+     - __le16
+     - e_value_offs
      - Location of this attribute's value on the disk block where it is stored.
        Multiple attributes can share the same value. For an inode attribute
        this value is relative to the start of the first entry; for a block this
        value is relative to the start of the block (i.e. the header).
    * - 0x4
-     - \_\_le32
-     - e\_value\_inum
+     - __le32
+     - e_value_inum
      - The inode where the value is stored. Zero indicates the value is in the
        same block as this entry. This field is only used if the
-       INCOMPAT\_EA\_INODE feature is enabled.
+       INCOMPAT_EA_INODE feature is enabled.
    * - 0x8
-     - \_\_le32
-     - e\_value\_size
+     - __le32
+     - e_value_size
      - Length of attribute value.
    * - 0xC
-     - \_\_le32
-     - e\_hash
+     - __le32
+     - e_hash
      - Hash value of attribute name and attribute value. The kernel doesn't
        update the hash for in-inode attributes, so for that case this value
        must be zero, because e2fsck validates any non-zero hash regardless of
        where the xattr lives.
    * - 0x10
      - char
-     - e\_name[e\_name\_len]
+     - e_name[e_name_len]
      - Attribute name. Does not include trailing NULL.
 
 Attribute values can follow the end of the entry table. There appears to
 be a requirement that they be aligned to 4-byte boundaries. The values
 are stored starting at the end of the block and grow towards the
-xattr\_header/xattr\_entry table. When the two collide, the overflow is
+xattr_header/xattr_entry table. When the two collide, the overflow is
 put into a separate disk block. If the disk block fills up, the
 filesystem returns -ENOSPC.
 
@@ -167,15 +167,15 @@ the key name. Here is a map of name index values to key prefixes:
    * - 1
      - “user.”
    * - 2
-     - “system.posix\_acl\_access”
+     - “system.posix_acl_access”
    * - 3
-     - “system.posix\_acl\_default”
+     - “system.posix_acl_default”
    * - 4
      - “trusted.”
    * - 6
      - “security.”
    * - 7
-     - “system.” (inline\_data only?)
+     - “system.” (inline_data only?)
    * - 8
      - “system.richacl” (SuSE kernels only?)
 

Documentation/filesystems/ext4/bigalloc.rst

@@ -23,7 +23,7 @@ means that a block group addresses 32 gigabytes instead of 128 megabytes,
 also shrinking the amount of file system overhead for metadata.
 
 The administrator can set a block cluster size at mkfs time (which is
-stored in the s\_log\_cluster\_size field in the superblock); from then
+stored in the s_log_cluster_size field in the superblock); from then
 on, the block bitmaps track clusters, not individual blocks. This means
 that block groups can be several gigabytes in size (instead of just
 128MiB); however, the minimum allocation unit becomes a cluster, not a

Documentation/filesystems/ext4/bitmaps.rst

@@ -9,15 +9,15 @@ group.
 The inode bitmap records which entries in the inode table are in use.
 
 As with most bitmaps, one bit represents the usage status of one data
-block or inode table entry. This implies a block group size of 8 \*
-number\_of\_bytes\_in\_a\_logical\_block.
+block or inode table entry. This implies a block group size of 8 *
+number_of_bytes_in_a_logical_block.
 
 NOTE: If ``BLOCK_UNINIT`` is set for a given block group, various parts
 of the kernel and e2fsprogs code pretends that the block bitmap contains
 zeros (i.e. all blocks in the group are free). However, it is not
 necessarily the case that no blocks are in use -- if ``meta_bg`` is set,
 the bitmaps and group descriptor live inside the group. Unfortunately,
-ext2fs\_test\_block\_bitmap2() will return '0' for those locations,
+ext2fs_test_block_bitmap2() will return '0' for those locations,
 which produces confusing debugfs output.
 
 Inode Table

Documentation/filesystems/ext4/blockgroup.rst

@@ -56,39 +56,39 @@ established that the super block and the group descriptor table, if
 present, will be at the beginning of the block group. The bitmaps and
 the inode table can be anywhere, and it is quite possible for the
 bitmaps to come after the inode table, or for both to be in different
-groups (flex\_bg). Leftover space is used for file data blocks, indirect
+groups (flex_bg). Leftover space is used for file data blocks, indirect
 block maps, extent tree blocks, and extended attributes.
 
 Flexible Block Groups
 ---------------------
 
 Starting in ext4, there is a new feature called flexible block groups
-(flex\_bg). In a flex\_bg, several block groups are tied together as one
+(flex_bg). In a flex_bg, several block groups are tied together as one
 logical block group; the bitmap spaces and the inode table space in the
-first block group of the flex\_bg are expanded to include the bitmaps
-and inode tables of all other block groups in the flex\_bg. For example,
-if the flex\_bg size is 4, then group 0 will contain (in order) the
+first block group of the flex_bg are expanded to include the bitmaps
+and inode tables of all other block groups in the flex_bg. For example,
+if the flex_bg size is 4, then group 0 will contain (in order) the
 superblock, group descriptors, data block bitmaps for groups 0-3, inode
 bitmaps for groups 0-3, inode tables for groups 0-3, and the remaining
 space in group 0 is for file data. The effect of this is to group the
 block group metadata close together for faster loading, and to enable
 large files to be continuous on disk. Backup copies of the superblock
 and group descriptors are always at the beginning of block groups, even
-if flex\_bg is enabled. The number of block groups that make up a
-flex\_bg is given by 2 ^ ``sb.s_log_groups_per_flex``.
+if flex_bg is enabled. The number of block groups that make up a
+flex_bg is given by 2 ^ ``sb.s_log_groups_per_flex``.
 
 Meta Block Groups
 -----------------
 
-Without the option META\_BG, for safety concerns, all block group
+Without the option META_BG, for safety concerns, all block group
 descriptors copies are kept in the first block group. Given the default
 128MiB(2^27 bytes) block group size and 64-byte group descriptors, ext4
 can have at most 2^27/64 = 2^21 block groups. This limits the entire
 filesystem size to 2^21 * 2^27 = 2^48bytes or 256TiB.
 
 The solution to this problem is to use the metablock group feature
-(META\_BG), which is already in ext3 for all 2.6 releases. With the
-META\_BG feature, ext4 filesystems are partitioned into many metablock
+(META_BG), which is already in ext3 for all 2.6 releases. With the
+META_BG feature, ext4 filesystems are partitioned into many metablock
 groups. Each metablock group is a cluster of block groups whose group
 descriptor structures can be stored in a single disk block. For ext4
 filesystems with 4 KB block size, a single metablock group partition
@@ -110,7 +110,7 @@ bytes, a meta-block group contains 32 block groups for filesystems with
 a 1KB block size, and 128 block groups for filesystems with a 4KB
 blocksize. Filesystems can either be created using this new block group
 descriptor layout, or existing filesystems can be resized on-line, and
-the field s\_first\_meta\_bg in the superblock will indicate the first
+the field s_first_meta_bg in the superblock will indicate the first
 block group using this new layout.
 
 Please see an important note about ``BLOCK_UNINIT`` in the section about
@@ -121,15 +121,15 @@ Lazy Block Group Initialization
 
 A new feature for ext4 are three block group descriptor flags that
 enable mkfs to skip initializing other parts of the block group
-metadata. Specifically, the INODE\_UNINIT and BLOCK\_UNINIT flags mean
+metadata. Specifically, the INODE_UNINIT and BLOCK_UNINIT flags mean
 that the inode and block bitmaps for that group can be calculated and
 therefore the on-disk bitmap blocks are not initialized. This is
 generally the case for an empty block group or a block group containing
-only fixed-location block group metadata. The INODE\_ZEROED flag means
+only fixed-location block group metadata. The INODE_ZEROED flag means
 that the inode table has been initialized; mkfs will unset this flag and
 rely on the kernel to initialize the inode tables in the background.
 
 By not writing zeroes to the bitmaps and inode table, mkfs time is
-reduced considerably. Note the feature flag is RO\_COMPAT\_GDT\_CSUM,
-but the dumpe2fs output prints this as “uninit\_bg”. They are the same
+reduced considerably. Note the feature flag is RO_COMPAT_GDT_CSUM,
+but the dumpe2fs output prints this as “uninit_bg”. They are the same
 thing.

Documentation/filesystems/ext4/blockmap.rst

@@ -1,7 +1,7 @@
 .. SPDX-License-Identifier: GPL-2.0
 
 +---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
-| i.i\_block Offset   | Where It Points                                                                                                                                                                                                              |
+| i.i_block Offset   | Where It Points                                                                                                                                                                                                              |
 +=====================+==============================================================================================================================================================================================================================+
 | 0 to 11             | Direct map to file blocks 0 to 11.                                                                                                                                                                                           |
 +---------------------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+

Documentation/filesystems/ext4/checksums.rst

@@ -4,7 +4,7 @@ Checksums
 ---------
 
 Starting in early 2012, metadata checksums were added to all major ext4
-and jbd2 data structures. The associated feature flag is metadata\_csum.
+and jbd2 data structures. The associated feature flag is metadata_csum.
 The desired checksum algorithm is indicated in the superblock, though as
 of October 2012 the only supported algorithm is crc32c. Some data
 structures did not have space to fit a full 32-bit checksum, so only the
@@ -20,7 +20,7 @@ encounters directory blocks that lack sufficient empty space to add a
 checksum, it will request that you run ``e2fsck -D`` to have the
 directories rebuilt with checksums. This has the added benefit of
 removing slack space from the directory files and rebalancing the htree
-indexes. If you \_ignore\_ this step, your directories will not be
+indexes. If you _ignore_ this step, your directories will not be
 protected by a checksum!
 
 The following table describes the data elements that go into each type
@@ -35,39 +35,39 @@ of checksum. The checksum function is whatever the superblock describes
      - Length
      - Ingredients
    * - Superblock
-     - \_\_le32
+     - __le32
      - The entire superblock up to the checksum field. The UUID lives inside
        the superblock.
    * - MMP
-     - \_\_le32
+     - __le32
      - UUID + the entire MMP block up to the checksum field.
    * - Extended Attributes
-     - \_\_le32
+     - __le32
      - UUID + the entire extended attribute block. The checksum field is set to
        zero.
    * - Directory Entries
-     - \_\_le32
+     - __le32
      - UUID + inode number + inode generation + the directory block up to the
        fake entry enclosing the checksum field.
    * - HTREE Nodes
-     - \_\_le32
+     - __le32
      - UUID + inode number + inode generation + all valid extents + HTREE tail.
        The checksum field is set to zero.
    * - Extents
-     - \_\_le32
+     - __le32
      - UUID + inode number + inode generation + the entire extent block up to
        the checksum field.
    * - Bitmaps
-     - \_\_le32 or \_\_le16
+     - __le32 or __le16
      - UUID + the entire bitmap. Checksums are stored in the group descriptor,
        and truncated if the group descriptor size is 32 bytes (i.e. ^64bit)
    * - Inodes
-     - \_\_le32
+     - __le32
      - UUID + inode number + inode generation + the entire inode. The checksum
        field is set to zero. Each inode has its own checksum.
    * - Group Descriptors
-     - \_\_le16
-     - If metadata\_csum, then UUID + group number + the entire descriptor;
-       else if gdt\_csum, then crc16(UUID + group number + the entire
+     - __le16
+     - If metadata_csum, then UUID + group number + the entire descriptor;
+       else if gdt_csum, then crc16(UUID + group number + the entire
        descriptor). In all cases, only the lower 16 bits are stored.