wireguard-linux/fs/orangefs/inode.c, branch jd/unified-crypt-queue

orangefs: get rid of knob code...

2020-04-08T13:38:51Z

Christoph Hellwig sent in a reversion of "orangefs: remember count when reading." because: ->read_iter calls can race with each other and one or more ->flush calls. Remove the the scheme to store the read count in the file private data as is is completely racy and can cause use after free or double free conditions Christoph's reversion caused Orangefs not to work or to compile. I added a patch that fixed that, but intel's kbuild test robot pointed out that sending Christoph's patch followed by my patch upstream, it would break bisection because of the failure to compile. So I have combined the reversion plus my patch... here's the commit message that was in my patch: Logically, optimal Orangefs "pages" are 4 megabytes. Reading large Orangefs files 4096 bytes at a time is like trying to kick a dead whale down the beach. Before Christoph's "Revert orangefs: remember count when reading." I tried to give users a knob whereby they could, for example, use "count" in read(2) or bs with dd(1) to get whatever they considered an appropriate amount of bytes at a time from Orangefs and fill as many page cache pages as they could at once. Without the racy code that Christoph reverted Orangefs won't even compile, much less work. So this replaces the logic that used the private file data that Christoph reverted with a static number of bytes to read from Orangefs. I ran tests like the following to determine what a reasonable static number of bytes might be: dd if=/pvfsmnt/asdf of=/dev/null count=128 bs=4194304 dd if=/pvfsmnt/asdf of=/dev/null count=256 bs=2097152 dd if=/pvfsmnt/asdf of=/dev/null count=512 bs=1048576 . . . dd if=/pvfsmnt/asdf of=/dev/null count=4194304 bs=128 Reads seem faster using the static number, so my "knob code" wasn't just racy, it wasn't even a good idea... Signed-off-by: Mike Marshall Reported-by: kbuild test robot

orangefs: posix open permission checking...

2019-12-04T13:52:55Z

Orangefs has no open, and orangefs checks file permissions on each file access. Posix requires that file permissions be checked on open and nowhere else. Orangefs-through-the-kernel needs to seem posix compliant. The VFS opens files, even if the filesystem provides no method. We can see if a file was successfully opened for read and or for write by looking at file->f_mode. When writes are flowing from the page cache, file is no longer available. We can trust the VFS to have checked file->f_mode before writing to the page cache. The mode of a file might change between when it is opened and IO commences, or it might be created with an arbitrary mode. We'll make sure we don't hit EACCES during the IO stage by using UID 0. Some of the time we have access without changing to UID 0 - how to check? Signed-off-by: Mike Marshall

orangefs: remove redundant assignment to err

2019-09-12T18:17:16Z

Variable err is initialized to a value that is never read and it is re-assigned later. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Signed-off-by: Mike Marshall

orangefs: truncate before updating size

2019-05-03T18:39:10Z

Otherwise we race with orangefs_writepage/orangefs_writepages which and does not expect i_size < page_offset. Fixes xfstests generic/129. Signed-off-by: Martin Brandenburg Signed-off-by: Mike Marshall

orangefs: copy Orangefs-sized blocks into the pagecache if possible.

2019-05-03T18:32:39Z

->readpage looks in file->private_data to try and find out how the userspace program set "count" in read(2) or with "dd bs=" or whatever. ->readpage uses "count" and inode->i_size to calculate how much data Orangefs should deposit in the Orangefs shared buffer, and remembers which slot the data is in. After copying data from the Orangefs shared buffer slot into "the page", readpage tries to increment through the pagecache index and fill as many pages as it can from the extra data in the shared buffer. Hopefully these extra pages will soon be needed by the vfs, and they'll be in the pagecache already. Signed-off-by: Mike Marshall Signed-off-by: Martin Brandenburg

orangefs: pass slot index back to readpage.

2019-05-03T18:32:39Z

When userspace deposits more than a page of data into the shared buffer, we'll need to know which slot it is in when we get back to readpage so that we can try to use the extra data to fill some extra pages. Signed-off-by: Mike Marshall Signed-off-by: Martin Brandenburg

orangefs: add orangefs_revalidate_mapping

2019-05-03T18:32:39Z

This is modeled after NFS, except our method is different. We use a simple timer to determine whether to invalidate the page cache. This is bound to perform. This addes a sysfs parameter cache_timeout_msecs which controls the time between page cache invalidations. Signed-off-by: Martin Brandenburg Signed-off-by: Mike Marshall

orangefs: write range tracking

2019-05-03T18:32:38Z

Attach the actual range of bytes written to plus the responsible uid/gid to each dirty page. This information must be sent to the server when the page is written out. Now write_begin, page_mkwrite, and invalidatepage keep up with this information. There are several conditions where they must write out the page immediately to store the new range. Two non-contiguous ranges cannot be stored on a single page. Signed-off-by: Martin Brandenburg Signed-off-by: Mike Marshall

orangefs: move do_readv_writev to direct_IO

2019-05-03T18:32:38Z

direct_IO was the only caller and all direct_IO did was call it, so there's no use in having the code spread out into so many functions. Signed-off-by: Martin Brandenburg Signed-off-by: Mike Marshall

orangefs: implement writepage

2019-05-03T18:32:38Z

Now orangefs_inode_getattr fills from cache if an inode has dirty pages. also if attr_valid and dirty pages and !flags, we spin on inode writeback before returning if pages still dirty after: should it be other way Signed-off-by: Martin Brandenburg Signed-off-by: Mike Marshall