kernel.git/fs/splice.c, branch linux-2.6.25.y

Don't allow splice() to files opened with O_APPEND

2008-10-22T21:05:15Z

commit efc968d450e013049a662d22727cf132618dcb2f upstream This is debatable, but while we're debating it, let's disallow the combination of splice and an O_APPEND destination. It's not entirely clear what the semantics of O_APPEND should be, and POSIX apparently expects pwrite() to ignore O_APPEND, for example. So we could make up any semantics we want, including the old ones. But Miklos convinced me that we should at least give it some thought, and that accepting writes at arbitrary offsets is wrong at least for IS_APPEND() files (which always have O_APPEND set, even if the reverse isn't true: you can obviously have O_APPEND set on a regular file). So disallow O_APPEND entirely for now. I doubt anybody cares, and this way we have one less gray area to worry about. Reported-and-argued-for-by: Miklos Szeredi Acked-by: Jens Axboe Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

splice: fix infinite loop in generic_file_splice_read()

2008-04-10T06:24:25Z

There's a quirky loop in generic_file_splice_read() that could go on indefinitely, if the file splice returns 0 permanently (and not just as a temporary condition). Get rid of the loop and pass back -EAGAIN correctly from __generic_file_splice_read(), so we handle that condition properly as well. Signed-off-by: Jens Axboe

splice: use mapping_gfp_mask

2008-04-03T22:39:49Z

The loop block driver is careful to mask __GFP_IO|__GFP_FS out of its mapping_gfp_mask, to avoid hangs under memory pressure. But nowadays it uses splice, usually going through __generic_file_splice_read. That must use mapping_gfp_mask instead of GFP_KERNEL to avoid those hangs. Signed-off-by: Hugh Dickins Cc: Jens Axboe Cc: Andrew Morton Signed-off-by: Linus Torvalds

splice: only return -EAGAIN if there's hope of more data

2008-03-04T10:14:39Z

sys_tee() currently is a bit eager in returning -EAGAIN, it may do so even if we don't have a chance of anymore data becoming available. So improve the logic and only return -EAGAIN if we have an attached writer to the input pipe. Reported by Johann Felix Soden and Patrick McManus . Tested-by: Johann Felix Soden Signed-off-by: Jens Axboe

splice: fix user pointer access in get_iovec_page_array()

2008-02-10T18:27:21Z

Commit 8811930dc74a503415b35c4a79d14fb0b408a361 ("splice: missing user pointer access verification") added the proper access_ok() calls to copy_from_user_mmap_sem() which ensures we can copy the struct iovecs from userspace to the kernel. But we also must check whether we can access the actual memory region pointed to by the struct iovec to fix the access checks properly. Signed-off-by: Bastian Blank Acked-by: Oliver Pinter Cc: Jens Axboe Cc: Andrew Morton Signed-off-by: Pekka Enberg Signed-off-by: Linus Torvalds

splice: missing user pointer access verification

2008-02-08T17:25:01Z

vmsplice_to_user() must always check the user pointer and length with access_ok() before copying. Likewise, for the slow path of copy_from_user_mmap_sem() we need to check that we may read from the user region. Signed-off-by: Jens Axboe Cc: Wojciech Purczynski Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds

splice: always updated atime in direct splice

2008-02-01T08:26:32Z

Andre Majorel points out that if we only updated the atime when we transfer some data, we deviate from the standard of always updating the atime. So change splice to always call file_accessed() even if splice_direct_to_actor() didn't transfer any data. Signed-off-by: Jens Axboe

splice: fix problem with atime not being updated

2008-01-29T20:55:20Z

A bug report on nfsd that states that since it was switched to use splice instead of sendfile, the atime was no longer being updated on the input file. do_generic_mapping_read() does this when accessing the file, make splice do it for the direct splice handler. Signed-off-by: Jens Axboe

[SPLICE]: Don't assume regular pages in splice_to_pipe()

2008-01-28T22:53:30Z

Allow caller to pass in a release function, there might be other resources that need releasing as well. Needed for network receive. Signed-off-by: Jens Axboe Signed-off-by: David S. Miller

security: call security_file_permission from rw_verify_area

2008-01-25T00:29:52Z

All instances of rw_verify_area() are followed by a call to security_file_permission(), so just call the latter from the former. Acked-by: Eric Paris Signed-off-by: James Morris