From: akpm@linux-foundation.org Subject: + add-buffer-head-related-helper-functions.patch added to -mm tree Date: Mon, 19 Nov 2007 23:19:57 -0800 Message-ID: <200711200719.lAK7JvUD020931@imap1.linux-foundation.org> Reply-To: linux-kernel@vger.kernel.org Cc: aneesh.kumar@linux.vnet.ibm.com, linux-ext4@vger.kernel.org To: mm-commits@vger.kernel.org Return-path: Sender: mm-commits-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org 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" 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 Cc: Signed-off-by: Andrew Morton --- 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@linux.vnet.ibm.com 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