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authorJens Axboe <axboe@kernel.dk>2024-12-20 08:47:50 -0700
committerAndrew Morton <akpm@linux-foundation.org>2025-01-25 20:22:44 -0800
commitd94d23fdd7529f1f3218235d1e0a69e9856907b7 (patch)
tree4d141ebef762478f35f56094ba9ce7b2da852598 /include/linux
parent1d4457576570627e1702614bc060b55d95b85e39 (diff)
mm: add FGP_DONTCACHE folio creation flag
Callers can pass this in for uncached folio creation, in which case if a folio is newly created it gets marked as uncached. If a folio exists for this index and lookup succeeds, then it will not get marked as uncached. If an !uncached lookup finds a cached folio, clear the flag. For that case, there are competeting uncached and cached users of the folio, and it should not get pruned. Link: https://lkml.kernel.org/r/20241220154831.1086649-13-axboe@kernel.dk Signed-off-by: Jens Axboe <axboe@kernel.dk> Cc: Brian Foster <bfoster@redhat.com> Cc: Chris Mason <clm@meta.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/pagemap.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index d53c49abead6..47bfc6b1b632 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -710,6 +710,7 @@ pgoff_t page_cache_prev_miss(struct address_space *mapping,
* * %FGP_NOFS - __GFP_FS will get cleared in gfp.
* * %FGP_NOWAIT - Don't block on the folio lock.
* * %FGP_STABLE - Wait for the folio to be stable (finished writeback)
+ * * %FGP_DONTCACHE - Uncached buffered IO
* * %FGP_WRITEBEGIN - The flags to use in a filesystem write_begin()
* implementation.
*/
@@ -723,6 +724,7 @@ typedef unsigned int __bitwise fgf_t;
#define FGP_NOWAIT ((__force fgf_t)0x00000020)
#define FGP_FOR_MMAP ((__force fgf_t)0x00000040)
#define FGP_STABLE ((__force fgf_t)0x00000080)
+#define FGP_DONTCACHE ((__force fgf_t)0x00000100)
#define FGF_GET_ORDER(fgf) (((__force unsigned)fgf) >> 26) /* top 6 bits */
#define FGP_WRITEBEGIN (FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE)