3eaf9cc62f
When the filesystem is created without a journal, we eventually call into __generic_file_fsync() in order to write out all the modified in-core data to the permanent storage device. This function happens to try and obtain an inode_lock() while synchronizing the files buffer and it's associated metadata. Generally, this is fine, however it becomes a problem when there is higher level code that has already obtained an inode_lock() as this leads to a recursive lock situation. This case is especially true when porting across direct I/O to iomap infrastructure as we obtain an inode_lock() early on in the I/O within ext4_dio_write_iter() and hold it until the I/O has been completed. Consequently, to not run into this specific issue, we move away from calling into __generic_file_fsync() and perform the necessary synchronization tasks within ext4_sync_file(). Signed-off-by: Matthew Bobrowski <mbobrowski@mbobrowski.org> Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/3495f35ef67f2021b567e28e6f59222e583689b8.1572949325.git.mbobrowski@mbobrowski.org Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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.
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.