linux/fs/fuse/dev.c, branch v4.0

fuse: explicitly set /dev/fuse file's private_data

2015-03-19T14:29:22Z

The misc subsystem (which is used for /dev/fuse) initializes private_data to point to the misc device when a driver has registered a custom open file operation, and initializes it to NULL when a custom open file operation has *not* been provided. This subtle quirk is confusing, to the point where kernel code registers *empty* file open operations to have private_data point to the misc device structure. And it leads to bugs, where the addition or removal of a custom open file operation surprisingly changes the initial contents of a file's private_data structure. So to simplify things in the misc subsystem, a patch [1] has been proposed to *always* set the private_data to point to the misc device, instead of only doing this when a custom open file operation has been registered. But before this patch can be applied we need to modify drivers that make the assumption that a misc device file's private_data is initialized to NULL because they didn't register a custom open file operation, so they don't rely on this assumption anymore. FUSE uses private_data to store the fuse_conn and errors out if this is not initialized to NULL at mount time. Hence, we now set a file's private_data to NULL explicitly, to be independent of whatever value the misc subsystem initializes it to by default. [1] https://lkml.org/lkml/2014/12/4/939 Reported-by: Giedrius Statkevicius Reported-by: Thierry Reding Signed-off-by: Tom Van Braeckel Signed-off-by: Miklos Szeredi

fuse: set stolen page uptodate

2015-02-26T10:45:47Z

Regular pipe buffers' ->steal method (generic_pipe_buf_steal()) doesn't set PG_uptodate. Don't warn on this condition, just set the uptodate flag. Signed-off-by: Miklos Szeredi Cc: stable@vger.kernel.org

fuse: notify: don't move pages

2015-02-26T10:45:47Z

fuse_try_move_page() is not prepared for replacing pages that have already been read. Reported-by: Al Viro Signed-off-by: Miklos Szeredi Cc: stable@vger.kernel.org

fuse: add memory barrier to INIT

2015-01-06T09:45:35Z

Theoretically we need to order setting of various fields in fc with fc->initialized. No known bug reports related to this yet. Signed-off-by: Miklos Szeredi

fuse: fix LOOKUP vs INIT compat handling

2015-01-06T09:45:35Z

Analysis from Marc: "Commit 7078187a795f ("fuse: introduce fuse_simple_request() helper") from the above pull request triggers some EIO errors for me in some tests that rely on fuse Looking at the code changes and a bit of debugging info I think there's a general problem here that fuse_get_req checks and possibly waits for fc->initialized, and this was always called first. But this commit changes the ordering and in many places fc->minor is now possibly used before fuse_get_req, and we can't be sure that fc has been initialized. In my case fuse_lookup_init sets req->out.args[0].size to the wrong size because fc->minor at that point is still 0, leading to the EIO error." Fix by moving the compat adjustments into fuse_simple_request() to after fuse_get_req(). This is also more readable than the original, since now compatibility is handled in a single function instead of cluttering each operation. Reported-by: Marc Dionne Tested-by: Marc Dionne Signed-off-by: Miklos Szeredi Fixes: 7078187a795f ("fuse: introduce fuse_simple_request() helper")

fuse: introduce fuse_simple_request() helper

2014-12-12T08:49:05Z

The following pattern is repeated many times: req = fuse_get_req_nopages(fc); /* Initialize req->(in|out).args */ fuse_request_send(fc, req); err = req->out.h.error; fuse_put_request(req); Create a new replacement helper: /* Initialize args */ err = fuse_simple_request(fc, &args); In addition to reducing the code size, this will ease moving from the complex arg-based to a simpler page-based I/O on the fuse device. Signed-off-by: Miklos Szeredi

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

2014-07-15T15:57:17Z

Pull fuse fixes from Miklos Szeredi: "This contains miscellaneous fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: replace count*size kzalloc by kcalloc fuse: release temporary page if fuse_writepage_locked() failed fuse: restructure ->rename2() fuse: avoid scheduling while atomic fuse: handle large user and group ID fuse: inode: drop cast fuse: ignore entry-timeout on LOOKUP_REVAL fuse: timeout comparison fix

fuse: avoid scheduling while atomic

2014-07-07T13:28:51Z

As reported by Richard Sharpe, an attempt to use fuse_notify_inval_entry() triggers complains about scheduling while atomic: BUG: scheduling while atomic: fuse.hf/13976/0x10000001 This happens because fuse_notify_inval_entry() attempts to allocate memory with GFP_KERNEL, holding "struct fuse_copy_state" mapped by kmap_atomic(). Introduced by commit 58bda1da4b3c "fuse/dev: use atomic maps" Fix by moving the map/unmap to just cover the actual memcpy operation. Original patch from Maxim Patlasov Reported-by: Richard Sharpe Signed-off-by: Miklos Szeredi Cc: # v3.15+

mm: page_alloc: convert hot/cold parameter and immediate callers to bool

2014-06-04T23:54:09Z

cold is a bool, make it one. Make the likely case the "if" part of the block instead of the else as according to the optimisation manual this is preferred. Signed-off-by: Mel Gorman Acked-by: Rik van Riel Cc: Johannes Weiner Cc: Vlastimil Babka Cc: Jan Kara Cc: Michal Hocko Cc: Hugh Dickins Cc: Dave Hansen Cc: Theodore Ts'o Cc: "Paul E. McKenney" Cc: Oleg Nesterov Cc: Peter Zijlstra Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

pipe: kill ->map() and ->unmap()

2014-04-02T03:19:19Z

all pipe_buffer_operations have the same instances of those... Signed-off-by: Al Viro