The patch titled
Add buffer head related helper functions
has been added to the -mm tree. Its filename is
add-buffer-head-related-helper-functions.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Add buffer head related helper functions
From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Add buffer head related helper function bh_uptodate_or_lock() and
bh_submit_read() which can be used by file systems.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: <linux-ext4@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/buffer.c | 41 ++++++++++++++++++++++++++++++++++
include/linux/buffer_head.h | 2 +
2 files changed, 43 insertions(+)
diff -puN fs/buffer.c~add-buffer-head-related-helper-functions fs/buffer.c
--- a/fs/buffer.c~add-buffer-head-related-helper-functions
+++ a/fs/buffer.c
@@ -3204,6 +3204,47 @@ init_buffer_head(struct kmem_cache *cach
INIT_LIST_HEAD(&bh->b_assoc_buffers);
}
+/**
+ * bh_uptodate_or_lock: Test whether the buffer is uptodate
+ * @bh: struct buffer_head
+ *
+ * Return true if the buffer is up-to-date and false,
+ * with the buffer locked, if not.
+ */
+int bh_uptodate_or_lock(struct buffer_head *bh)
+{
+ if (!buffer_uptodate(bh)) {
+ lock_buffer(bh);
+ if (!buffer_uptodate(bh))
+ return 0;
+ unlock_buffer(bh);
+ }
+ return 1;
+}
+EXPORT_SYMBOL(bh_uptodate_or_lock);
+/**
+ * bh_submit_read: Submit a locked buffer for reading
+ * @bh: struct buffer_head
+ *
+ * Returns a negative error
+ */
+int bh_submit_read(struct buffer_head *bh)
+{
+ if (!buffer_locked(bh))
+ lock_buffer(bh);
+
+ if (buffer_uptodate(bh))
+ return 0;
+
+ get_bh(bh);
+ bh->b_end_io = end_buffer_read_sync;
+ submit_bh(READ, bh);
+ wait_on_buffer(bh);
+ if (buffer_uptodate(bh))
+ return 0;
+ return -EIO;
+}
+EXPORT_SYMBOL(bh_submit_read);
void __init buffer_init(void)
{
int nrpages;
diff -puN include/linux/buffer_head.h~add-buffer-head-related-helper-functions include/linux/buffer_head.h
--- a/include/linux/buffer_head.h~add-buffer-head-related-helper-functions
+++ a/include/linux/buffer_head.h
@@ -192,6 +192,8 @@ int sync_dirty_buffer(struct buffer_head
int submit_bh(int, struct buffer_head *);
void write_boundary_block(struct block_device *bdev,
sector_t bblock, unsigned blocksize);
+int bh_uptodate_or_lock(struct buffer_head *bh);
+int bh_submit_read(struct buffer_head *bh);
extern int buffer_heads_over_limit;
_
Patches currently in -mm which might be from aneesh.kumar@xxxxxxxxxxxxxxxxxx are
ext2-return-after-ext2_error-in-case-of-failures.patch
ext2-change-the-default-behaviour-on-error.patch
add-buffer-head-related-helper-functions.patch
ext2-add-block-bitmap-validation.patch
ext3-add-block-bitmap-validation.patch
ext4-add-block-bitmap-validation.patch
ext3-return-after-ext3_error-in-case-of-failures.patch
ext3-change-the-default-behaviour-on-error.patch
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