Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
new file mode 100644
index 0000000..f7a1390
--- /dev/null
+++ b/include/linux/backing-dev.h
@@ -0,0 +1,104 @@
+/*
+ * include/linux/backing-dev.h
+ *
+ * low-level device information and state which is propagated up through
+ * to high-level code.
+ */
+
+#ifndef _LINUX_BACKING_DEV_H
+#define _LINUX_BACKING_DEV_H
+
+#include <asm/atomic.h>
+
+/*
+ * Bits in backing_dev_info.state
+ */
+enum bdi_state {
+ BDI_pdflush, /* A pdflush thread is working this device */
+ BDI_write_congested, /* The write queue is getting full */
+ BDI_read_congested, /* The read queue is getting full */
+ BDI_unused, /* Available bits start here */
+};
+
+typedef int (congested_fn)(void *, int);
+
+struct backing_dev_info {
+ unsigned long ra_pages; /* max readahead in PAGE_CACHE_SIZE units */
+ unsigned long state; /* Always use atomic bitops on this */
+ unsigned int capabilities; /* Device capabilities */
+ congested_fn *congested_fn; /* Function pointer if device is md/dm */
+ void *congested_data; /* Pointer to aux data for congested func */
+ void (*unplug_io_fn)(struct backing_dev_info *, struct page *);
+ void *unplug_io_data;
+};
+
+
+/*
+ * Flags in backing_dev_info::capability
+ * - The first two flags control whether dirty pages will contribute to the
+ * VM's accounting and whether writepages() should be called for dirty pages
+ * (something that would not, for example, be appropriate for ramfs)
+ * - These flags let !MMU mmap() govern direct device mapping vs immediate
+ * copying more easily for MAP_PRIVATE, especially for ROM filesystems
+ */
+#define BDI_CAP_NO_ACCT_DIRTY 0x00000001 /* Dirty pages shouldn't contribute to accounting */
+#define BDI_CAP_NO_WRITEBACK 0x00000002 /* Don't write pages back */
+#define BDI_CAP_MAP_COPY 0x00000004 /* Copy can be mapped (MAP_PRIVATE) */
+#define BDI_CAP_MAP_DIRECT 0x00000008 /* Can be mapped directly (MAP_SHARED) */
+#define BDI_CAP_READ_MAP 0x00000010 /* Can be mapped for reading */
+#define BDI_CAP_WRITE_MAP 0x00000020 /* Can be mapped for writing */
+#define BDI_CAP_EXEC_MAP 0x00000040 /* Can be mapped for execution */
+#define BDI_CAP_VMFLAGS \
+ (BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP)
+
+#if defined(VM_MAYREAD) && \
+ (BDI_CAP_READ_MAP != VM_MAYREAD || \
+ BDI_CAP_WRITE_MAP != VM_MAYWRITE || \
+ BDI_CAP_EXEC_MAP != VM_MAYEXEC)
+#error please change backing_dev_info::capabilities flags
+#endif
+
+extern struct backing_dev_info default_backing_dev_info;
+void default_unplug_io_fn(struct backing_dev_info *bdi, struct page *page);
+
+int writeback_acquire(struct backing_dev_info *bdi);
+int writeback_in_progress(struct backing_dev_info *bdi);
+void writeback_release(struct backing_dev_info *bdi);
+
+static inline int bdi_congested(struct backing_dev_info *bdi, int bdi_bits)
+{
+ if (bdi->congested_fn)
+ return bdi->congested_fn(bdi->congested_data, bdi_bits);
+ return (bdi->state & bdi_bits);
+}
+
+static inline int bdi_read_congested(struct backing_dev_info *bdi)
+{
+ return bdi_congested(bdi, 1 << BDI_read_congested);
+}
+
+static inline int bdi_write_congested(struct backing_dev_info *bdi)
+{
+ return bdi_congested(bdi, 1 << BDI_write_congested);
+}
+
+static inline int bdi_rw_congested(struct backing_dev_info *bdi)
+{
+ return bdi_congested(bdi, (1 << BDI_read_congested)|
+ (1 << BDI_write_congested));
+}
+
+#define bdi_cap_writeback_dirty(bdi) \
+ (!((bdi)->capabilities & BDI_CAP_NO_WRITEBACK))
+
+#define bdi_cap_account_dirty(bdi) \
+ (!((bdi)->capabilities & BDI_CAP_NO_ACCT_DIRTY))
+
+#define mapping_cap_writeback_dirty(mapping) \
+ bdi_cap_writeback_dirty((mapping)->backing_dev_info)
+
+#define mapping_cap_account_dirty(mapping) \
+ bdi_cap_account_dirty((mapping)->backing_dev_info)
+
+
+#endif /* _LINUX_BACKING_DEV_H */