It would seem that the disk format doesn't actually change depending on ATTRBIT and ATTR2BIT. The key difference is that ATTR2BIT (without the 'noattr2' mount option) allows di_forkoff to change depending on how much space the attr fork needs, whereas ATTRBIT (without ATTR2BIT or the 'attr2' mount option) does not allow di_forkoff to change. In other words, at least one of the bits must be set if there are extended attributes, but between the two bits the only difference is a change in the default di_forkoff adjustment behaviors. Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> --- .../allocation_groups.asciidoc | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/design/XFS_Filesystem_Structure/allocation_groups.asciidoc b/design/XFS_Filesystem_Structure/allocation_groups.asciidoc index 51ca57d..68f934a 100644 --- a/design/XFS_Filesystem_Structure/allocation_groups.asciidoc +++ b/design/XFS_Filesystem_Structure/allocation_groups.asciidoc @@ -174,7 +174,13 @@ indicate features introduced over time. If the value of the lower nibble is >= [options="header"] |===== | Flag | Description -| +XFS_SB_VERSION_ATTRBIT+ | Set if any inode have extended attributes. +| +XFS_SB_VERSION_ATTRBIT+ | +Set if any inode have extended attributes. If this bit is set; the ++XFS_SB_VERSION2_ATTR2BIT+ is not set; and the +attr2+ mount flag is not +specified, the +di_forkoff+ inode field will not be dynamically adjusted. +See the section about xref:Extended_Attribute_Versions[extended attribute +versions] for more information. + | +XFS_SB_VERSION_NLINKBIT+ | Set if any inodes use 32-bit di_nlink values. | +XFS_SB_VERSION_QUOTABIT+ | Quotas are enabled on the filesystem. This @@ -335,10 +341,11 @@ performance. The global free space and inode counts are only updated in the primary superblock when the filesystem is cleanly unmounted. | +XFS_SB_VERSION2_ATTR2BIT+ | -Extended attributes version 2. Making a filesystem with this optimises the inode -layout of extended attributes. See the section about -xref:Extended_Attribute_Versions[extended attribute versions] for more -information. +Extended attributes version 2. Making a filesystem with this optimises the +inode layout of extended attributes. If this bit is set and the +noattr2+ +mount flag is not specified, the +di_forkoff+ inode field will be dynamically +adjusted. See the section about xref:Extended_Attribute_Versions[extended +attribute versions] for more information. | +XFS_SB_VERSION2_PARENTBIT+ | Parent pointers. All inodes must have an extended attribute that points back to -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
