linux/fs/read_write.c, branch v4.20

vfs: allow some remap flags to be passed to vfs_clone_file_range

2018-12-04T16:50:49Z

In overlayfs, ovl_remap_file_range calls vfs_clone_file_range on the lower filesystem's inode, passing through whatever remap flags it got from its caller. Since vfs_copy_file_range first tries a filesystem's remap function with REMAP_FILE_CAN_SHORTEN, this can get passed through to the second vfs_copy_file_range call, and this isn't an issue. Change the WARN_ON to look only for the DEDUP flag. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein Reviewed-by: Christoph Hellwig

vfs: vfs_dedupe_file_range() doesn't return EOPNOTSUPP

2018-11-21T18:10:54Z

It returns EINVAL when the operation is not supported by the filesystem. Fix it to return EOPNOTSUPP to be consistent with the man page and clone_file_range(). Clean up the inconsistent error return handling while I'm there. (I know, lipstick on a pig, but every little bit helps...) Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

Merge tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2018-11-02T16:33:08Z

Pull vfs dedup fixes from Dave Chinner: "This reworks the vfs data cloning infrastructure. We discovered many issues with these interfaces late in the 4.19 cycle - the worst of them (data corruption, setuid stripping) were fixed for XFS in 4.19-rc8, but a larger rework of the infrastructure fixing all the problems was needed. That rework is the contents of this pull request. Rework the vfs_clone_file_range and vfs_dedupe_file_range infrastructure to use a common .remap_file_range method and supply generic bounds and sanity checking functions that are shared with the data write path. The current VFS infrastructure has problems with rlimit, LFS file sizes, file time stamps, maximum filesystem file sizes, stripping setuid bits, etc and so they are addressed in these commits. We also introduce the ability for the ->remap_file_range methods to return short clones so that clones for vfs_copy_file_range() don't get rejected if the entire range can't be cloned. It also allows filesystems to sliently skip deduplication of partial EOF blocks if they are not capable of doing so without requiring errors to be thrown to userspace. Existing filesystems are converted to user the new remap_file_range method, and both XFS and ocfs2 are modified to make use of the new generic checking infrastructure" * tag 'xfs-4.20-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (28 commits) xfs: remove [cm]time update from reflink calls xfs: remove xfs_reflink_remap_range xfs: remove redundant remap partial EOF block checks xfs: support returning partial reflink results xfs: clean up xfs_reflink_remap_blocks call site xfs: fix pagecache truncation prior to reflink ocfs2: remove ocfs2_reflink_remap_range ocfs2: support partial clone range and dedupe range ocfs2: fix pagecache truncation prior to reflink ocfs2: truncate page cache for clone destination file before remapping vfs: clean up generic_remap_file_range_prep return value vfs: hide file range comparison function vfs: enable remap callers that can handle short operations vfs: plumb remap flags through the vfs dedupe functions vfs: plumb remap flags through the vfs clone functions vfs: make remap_file_range functions take and return bytes completed vfs: remap helper should update destination inode metadata vfs: pass remap flags to generic_remap_checks vfs: pass remap flags to generic_remap_file_range_prep vfs: combine the clone and dedupe into a single remap_file_range ...

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2018-11-02T03:19:49Z

Pull misc vfs updates from Al Viro: "No common topic, really - a handful of assorted stuff; the least trivial bits are Mark's dedupe patches" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs/exofs: only use true/false for asignment of bool type variable fs/exofs: fix potential memory leak in mount option parsing Delete invalid assignment statements in do_sendfile iomap: remove duplicated include from iomap.c vfs: dedupe should return EPERM if permission is not granted vfs: allow dedupe of user owned read-only files ntfs: don't open-code ERR_CAST ext4: don't open-code ERR_CAST

vfs: clean up generic_remap_file_range_prep return value

2018-10-29T23:42:24Z

Since the remap prep function can update the length of the remap request, we can change this function to return the usual return status instead of the odd behavior it has now. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner

vfs: hide file range comparison function

2018-10-29T23:42:17Z

There are no callers of vfs_dedupe_file_range_compare, so we might as well make it a static helper and remove the export. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein Reviewed-by: Christoph Hellwig Signed-off-by: Dave Chinner

vfs: enable remap callers that can handle short operations

2018-10-29T23:42:10Z

Plumb in a remap flag that enables the filesystem remap handler to shorten remapping requests for callers that can handle it. Now copy_file_range can report partial success (in case we run up against alignment problems, resource limits, etc.). We also enable CAN_SHORTEN for fideduperange to maintain existing userspace-visible behavior where xfs/btrfs shorten the dedupe range to avoid stale post-eof data exposure. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein Signed-off-by: Dave Chinner

vfs: plumb remap flags through the vfs dedupe functions

2018-10-29T23:42:03Z

Plumb a remap_flags argument through the vfs_dedupe_file_range_one functions so that dedupe can take advantage of it. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein Signed-off-by: Dave Chinner

vfs: plumb remap flags through the vfs clone functions

2018-10-29T23:41:56Z

Plumb a remap_flags argument through the {do,vfs}_clone_file_range functions so that clone can take advantage of it. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein Signed-off-by: Dave Chinner

vfs: make remap_file_range functions take and return bytes completed

2018-10-29T23:41:49Z

Change the remap_file_range functions to take a number of bytes to operate upon and return the number of bytes they operated on. This is a requirement for allowing fs implementations to return short clone/dedupe results to the user, which will enable us to obey resource limits in a graceful manner. A subsequent patch will enable copy_file_range to signal to the ->clone_file_range implementation that it can handle a short length, which will be returned in the function's return value. For now the short return is not implemented anywhere so the behavior won't change -- either copy_file_range manages to clone the entire range or it tries an alternative. Neither clone ioctl can take advantage of this, alas. Signed-off-by: Darrick J. Wong Reviewed-by: Amir Goldstein Signed-off-by: Dave Chinner