aafe12cee0
If we somehow end up with a filesystem that has fewer free blocks than the blocks set aside to avoid ENOSPC deadlocks, it's possible that the free space calculation in xfs_reserve_blocks will spit out a negative number (because percpu_counter_sum returns s64). We fail to notice this negative number and set fdblks_delta to it. Now we increment fdblocks(!) and the unsigned type of m_resblks means that we end up setting a ridiculously huge m_resblks reservation. Avoid this comedy of errors by detecting the negative free space and returning -ENOSPC. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Allison Henderson <allison.henderson@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.