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| author | Christoph Hellwig <hch@lst.de> | 2016-10-03 00:48:08 +0200 |
|---|---|---|
| committer | Dave Chinner <david@fromorbit.com> | 2016-10-03 00:48:08 +0200 |
| commit | 0d5b0cf246a3227d811e7bf55d756b273408e414 (patch) | |
| tree | 08163c5359913d1747cc2ef74394b313c0949cbd | |
| parent | xfs: update atime before I/O in xfs_file_dio_aio_read (diff) | |
| download | linux-0d5b0cf246a3227d811e7bf55d756b273408e414.tar.xz linux-0d5b0cf246a3227d811e7bf55d756b273408e414.zip | |
fs: update atime before I/O in generic_file_read_iter
After the call to ->direct_IO the final reference to the file might have
been dropped by aio_complete already, and the call to file_accessed might
cause a use after free.
Instead update the access time before the I/O, similar to how we
update the time stamps before writes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
| -rw-r--r-- | mm/filemap.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 8a287dfc5372..2f1175e86c77 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1910,16 +1910,18 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) if (iocb->ki_flags & IOCB_DIRECT) { struct address_space *mapping = file->f_mapping; struct inode *inode = mapping->host; + struct iov_iter data = *iter; loff_t size; size = i_size_read(inode); retval = filemap_write_and_wait_range(mapping, iocb->ki_pos, iocb->ki_pos + count - 1); - if (!retval) { - struct iov_iter data = *iter; - retval = mapping->a_ops->direct_IO(iocb, &data); - } + if (retval < 0) + goto out; + file_accessed(file); + + retval = mapping->a_ops->direct_IO(iocb, &data); if (retval > 0) { iocb->ki_pos += retval; iov_iter_advance(iter, retval); @@ -1935,10 +1937,8 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter) * DAX files, so don't bother trying. */ if (retval < 0 || !iov_iter_count(iter) || iocb->ki_pos >= size || - IS_DAX(inode)) { - file_accessed(file); + IS_DAX(inode)) goto out; - } } retval = do_generic_file_read(file, &iocb->ki_pos, iter, retval); |