5f3e951186
This series employs atomic extent swapping to enable safe reconstruction of extended attribute data attached to a file. Because xattrs do not have any redundant information to draw off of, we can at best salvage as much data as we can and build a new structure. Rebuilding an extended attribute structure consists of these three steps: First, we walk the existing attributes to salvage as many of them as we can, by adding them as new attributes attached to the repair tempfile. We need to add a new xfile-based data structure to hold blobs of arbitrary length to stage the xattr names and values. Second, we write the salvaged attributes to a temporary file, and use atomic extent swaps to exchange the entire attribute fork between the two files. Finally, we reap the old xattr blocks (which are now in the temporary file) as carefully as we can. This has been running on the djcloud for months with no problems. Enjoy! Signed-off-by: Darrick J. Wong <djwong@kernel.org> -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQQ2qTKExjcn+O1o2YRKO3ySh0YRpgUCZh23UwAKCRBKO3ySh0YR pgtVAQDEjDtM1TqUn8neJtXqtOPC2FZdLFq6Z1uSzxGWSRi9TwD/fcwgpvIrdF7g LFrCRk9UUJZRxrK6kGb+RcEtSJwwNwc= =FVWN -----END PGP SIGNATURE----- Merge tag 'repair-xattrs-6.10_2024-04-15' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-6.10-mergeA xfs: online repair of extended attributes This series employs atomic extent swapping to enable safe reconstruction of extended attribute data attached to a file. Because xattrs do not have any redundant information to draw off of, we can at best salvage as much data as we can and build a new structure. Rebuilding an extended attribute structure consists of these three steps: First, we walk the existing attributes to salvage as many of them as we can, by adding them as new attributes attached to the repair tempfile. We need to add a new xfile-based data structure to hold blobs of arbitrary length to stage the xattr names and values. Second, we write the salvaged attributes to a temporary file, and use atomic extent swaps to exchange the entire attribute fork between the two files. Finally, we reap the old xattr blocks (which are now in the temporary file) as carefully as we can. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org> * tag 'repair-xattrs-6.10_2024-04-15' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux: xfs: create an xattr iteration function for scrub xfs: flag empty xattr leaf blocks for optimization xfs: scrub should set preen if attr leaf has holes xfs: repair extended attributes xfs: use atomic extent swapping to fix user file fork data xfs: create a blob array data structure xfs: enable discarding of folios backing an xfile
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.