Eric Lee / smarc-ti-linux-kernel

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Commit 205f87f6b342444f722e4559d33318686f7df2ca

Authored by Badari Pulavarty
Committed by Linus Torvalds
1 parent d48589bfad
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

[PATCH] change buffer_head.b_size to size_t 

Increase the size of the buffer_head b_size field (only) for 64 bit platforms.
Update some old and moldy comments in and around the structure as well.

The b_size increase allows us to perform larger mappings and allocations for
large I/O requests from userspace, which tie in with other changes allowing
the get_block_t() interface to map multiple blocks at once.

Signed-off-by: Nathan Scott <nathans@sgi.com>
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Showing 4 changed files with 17 additions and 12 deletions Side-by-side Diff

... ... @@ -426,8 +426,10 @@
426 426 if (all_mapped) {
427 427 printk("__find_get_block_slow() failed. "
428 428 "block=%llu, b_blocknr=%llu\n",
429   - (unsigned long long)block, (unsigned long long)bh->b_blocknr);
430   - printk("b_state=0x%08lx, b_size=%u\n", bh->b_state, bh->b_size);
  429 + (unsigned long long)block,
  430 + (unsigned long long)bh->b_blocknr);
  431 + printk("b_state=0x%08lx, b_size=%zu\n",
  432 + bh->b_state, bh->b_size);
431 433 printk("device blocksize: %d\n", 1 << bd_inode->i_blkbits);
432 434 }
433 435 out_unlock:
... ... @@ -377,7 +377,7 @@
377 377 BUG_ON(!bh);
378 378 BUG_ON(!(handle->flags & OCFS2_HANDLE_STARTED));
379 379  
380   - mlog_entry("bh->b_blocknr=%llu, type=%d (\"%s\"), bh->b_size = %hu\n",
  380 + mlog_entry("bh->b_blocknr=%llu, type=%d (\"%s\"), bh->b_size = %zu\n",
381 381 (unsigned long long)bh->b_blocknr, type,
382 382 (type == OCFS2_JOURNAL_ACCESS_CREATE) ?
383 383 "OCFS2_JOURNAL_ACCESS_CREATE" :
fs/reiserfs/prints.c
Diff comments   View file @ 205f87f
... ... @@ -143,7 +143,7 @@
143 143 char b[BDEVNAME_SIZE];
144 144  
145 145 sprintf(buf,
146   - "dev %s, size %d, blocknr %llu, count %d, state 0x%lx, page %p, (%s, %s, %s)",
  146 + "dev %s, size %zd, blocknr %llu, count %d, state 0x%lx, page %p, (%s, %s, %s)",
147 147 bdevname(bh->b_bdev, b), bh->b_size,
148 148 (unsigned long long)bh->b_blocknr, atomic_read(&(bh->b_count)),
149 149 bh->b_state, bh->b_page,
include/linux/buffer_head.h
Diff comments   View file @ 205f87f
... ... @@ -46,25 +46,28 @@
46 46 typedef void (bh_end_io_t)(struct buffer_head *bh, int uptodate);
47 47  
48 48 /*
49   - * Keep related fields in common cachelines. The most commonly accessed
50   - * field (b_state) goes at the start so the compiler does not generate
51   - * indexed addressing for it.
  49 + * Historically, a buffer_head was used to map a single block
  50 + * within a page, and of course as the unit of I/O through the
  51 + * filesystem and block layers. Nowadays the basic I/O unit
  52 + * is the bio, and buffer_heads are used for extracting block
  53 + * mappings (via a get_block_t call), for tracking state within
  54 + * a page (via a page_mapping) and for wrapping bio submission
  55 + * for backward compatibility reasons (e.g. submit_bh).
52 56 */
53 57 struct buffer_head {
54   - /* First cache line: */
55 58 unsigned long b_state; /* buffer state bitmap (see above) */
56 59 struct buffer_head *b_this_page;/* circular list of page's buffers */
57 60 struct page *b_page; /* the page this bh is mapped to */
58   - atomic_t b_count; /* users using this block */
59   - u32 b_size; /* block size */
60 61  
61   - sector_t b_blocknr; /* block number */
62   - char *b_data; /* pointer to data block */
  62 + sector_t b_blocknr; /* start block number */
  63 + size_t b_size; /* size of mapping */
  64 + char *b_data; /* pointer to data within the page */
63 65  
64 66 struct block_device *b_bdev;
65 67 bh_end_io_t *b_end_io; /* I/O completion */
66 68 void *b_private; /* reserved for b_end_io */
67 69 struct list_head b_assoc_buffers; /* associated with another mapping */
  70 + atomic_t b_count; /* users using this buffer_head */
68 71 };
69 72  
70 73 /*