Messages in this thread Patch in this message | | | From | Mathieu Desnoyers <> | Subject | [RFC PATCH v3 2/4] dax: Check for data cache aliasing at runtime | Date | Wed, 31 Jan 2024 11:25:31 -0500 |
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Replace the following fs/Kconfig:FS_DAX dependency:
depends on !(ARM || MIPS || SPARC)
By a runtime check within alloc_dax().
This is done in preparation for its use by each filesystem supporting the "dax" mount option to validate whether DAX is indeed supported.
This is done in preparation for using cpu_dcache_is_aliasing() in a following change which will properly support architectures which detect data cache aliasing at runtime.
Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches") Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-mm@kvack.org Cc: linux-arch@vger.kernel.org Cc: Dan Williams <dan.j.williams@intel.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk> Cc: nvdimm@lists.linux.dev Cc: linux-cxl@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: dm-devel@lists.linux.dev --- drivers/dax/super.c | 6 ++++++ fs/Kconfig | 1 - 2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 0da9232ea175..e9f397b8a5a3 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -445,6 +445,12 @@ struct dax_device *alloc_dax(void *private, const struct dax_operations *ops) dev_t devt; int minor; + /* Unavailable on architectures with virtually aliased data caches. */ + if (IS_ENABLED(CONFIG_ARM) || + IS_ENABLED(CONFIG_MIPS) || + IS_ENABLED(CONFIG_SPARC)) + return NULL; + if (WARN_ON_ONCE(ops && !ops->zero_page_range)) return ERR_PTR(-EINVAL); diff --git a/fs/Kconfig b/fs/Kconfig index 42837617a55b..e5efdb3b276b 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -56,7 +56,6 @@ endif # BLOCK config FS_DAX bool "File system based Direct Access (DAX) support" depends on MMU - depends on !(ARM || MIPS || SPARC) depends on ZONE_DEVICE || FS_DAX_LIMITED select FS_IOMAP select DAX -- 2.39.2
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