From: Lukas Czerner Subject: [PATCH 11/15 v2] ext4: remove unused discard_partial_page_buffers Date: Fri, 31 Aug 2012 18:21:47 -0400 Message-ID: <1346451711-1931-12-git-send-email-lczerner@redhat.com> References: <1346451711-1931-1-git-send-email-lczerner@redhat.com> Cc: linux-ext4@vger.kernel.org, tytso@mit.edu, hughd@google.com, linux-mm@kvack.org, Lukas Czerner To: linux-fsdevel@vger.kernel.org Return-path: In-Reply-To: <1346451711-1931-1-git-send-email-lczerner@redhat.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org The discard_partial_page_buffers is no longer used anywhere so we can simply remove it including the *_no_lock variant and EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED define. Signed-off-by: Lukas Czerner --- fs/ext4/ext4.h | 8 -- fs/ext4/inode.c | 206 ------------------------------------------------------- 2 files changed, 0 insertions(+), 214 deletions(-) diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 54ee9f3..47dba3c 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -585,11 +585,6 @@ enum { #define EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER 0x0020 /* - * Flags used by ext4_discard_partial_page_buffers - */ -#define EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED 0x0001 - -/* * ioctl commands */ #define EXT4_IOC_GETFLAGS FS_IOC_GETFLAGS @@ -2007,9 +2002,6 @@ extern int ext4_block_zero_page_range(handle_t *handle, struct address_space *mapping, loff_t from, loff_t length); extern int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode, loff_t lstart, loff_t lend); -extern int ext4_discard_partial_page_buffers(handle_t *handle, - struct address_space *mapping, loff_t from, - loff_t length, int flags); extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf); extern qsize_t *ext4_get_reserved_space(struct inode *inode); extern void ext4_da_update_reserve_space(struct inode *inode, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index d9c4a28..95111b4 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -139,9 +139,6 @@ static int ext4_set_bh_endio(struct buffer_head *bh, struct inode *inode); static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate); static int __ext4_journalled_writepage(struct page *page, unsigned int len); static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh); -static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle, - struct inode *inode, struct page *page, loff_t from, - loff_t length, int flags); /* * Test whether an inode is a fast symlink. @@ -3287,209 +3284,6 @@ void ext4_set_aops(struct inode *inode) } } - -/* - * ext4_discard_partial_page_buffers() - * Wrapper function for ext4_discard_partial_page_buffers_no_lock. - * This function finds and locks the page containing the offset - * "from" and passes it to ext4_discard_partial_page_buffers_no_lock. - * Calling functions that already have the page locked should call - * ext4_discard_partial_page_buffers_no_lock directly. - */ -int ext4_discard_partial_page_buffers(handle_t *handle, - struct address_space *mapping, loff_t from, - loff_t length, int flags) -{ - struct inode *inode = mapping->host; - struct page *page; - int err = 0; - - page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT, - mapping_gfp_mask(mapping) & ~__GFP_FS); - if (!page) - return -ENOMEM; - - err = ext4_discard_partial_page_buffers_no_lock(handle, inode, page, - from, length, flags); - - unlock_page(page); - page_cache_release(page); - return err; -} - -/* - * ext4_discard_partial_page_buffers_no_lock() - * Zeros a page range of length 'length' starting from offset 'from'. - * Buffer heads that correspond to the block aligned regions of the - * zeroed range will be unmapped. Unblock aligned regions - * will have the corresponding buffer head mapped if needed so that - * that region of the page can be updated with the partial zero out. - * - * This function assumes that the page has already been locked. The - * The range to be discarded must be contained with in the given page. - * If the specified range exceeds the end of the page it will be shortened - * to the end of the page that corresponds to 'from'. This function is - * appropriate for updating a page and it buffer heads to be unmapped and - * zeroed for blocks that have been either released, or are going to be - * released. - * - * handle: The journal handle - * inode: The files inode - * page: A locked page that contains the offset "from" - * from: The starting byte offset (from the begining of the file) - * to begin discarding - * len: The length of bytes to discard - * flags: Optional flags that may be used: - * - * EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED - * Only zero the regions of the page whose buffer heads - * have already been unmapped. This flag is appropriate - * for updateing the contents of a page whose blocks may - * have already been released, and we only want to zero - * out the regions that correspond to those released blocks. - * - * Returns zero on sucess or negative on failure. - */ -static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle, - struct inode *inode, struct page *page, loff_t from, - loff_t length, int flags) -{ - ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; - unsigned int offset = from & (PAGE_CACHE_SIZE-1); - unsigned int blocksize, max, pos; - ext4_lblk_t iblock; - struct buffer_head *bh; - int err = 0; - - blocksize = inode->i_sb->s_blocksize; - max = PAGE_CACHE_SIZE - offset; - - if (index != page->index) - return -EINVAL; - - /* - * correct length if it does not fall between - * 'from' and the end of the page - */ - if (length > max || length < 0) - length = max; - - iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); - - if (!page_has_buffers(page)) - create_empty_buffers(page, blocksize, 0); - - /* Find the buffer that contains "offset" */ - bh = page_buffers(page); - pos = blocksize; - while (offset >= pos) { - bh = bh->b_this_page; - iblock++; - pos += blocksize; - } - - pos = offset; - while (pos < offset + length) { - unsigned int end_of_block, range_to_discard; - - err = 0; - - /* The length of space left to zero and unmap */ - range_to_discard = offset + length - pos; - - /* The length of space until the end of the block */ - end_of_block = blocksize - (pos & (blocksize-1)); - - /* - * Do not unmap or zero past end of block - * for this buffer head - */ - if (range_to_discard > end_of_block) - range_to_discard = end_of_block; - - - /* - * Skip this buffer head if we are only zeroing unampped - * regions of the page - */ - if (flags & EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED && - buffer_mapped(bh)) - goto next; - - /* If the range is block aligned, unmap */ - if (range_to_discard == blocksize) { - clear_buffer_dirty(bh); - bh->b_bdev = NULL; - clear_buffer_mapped(bh); - clear_buffer_req(bh); - clear_buffer_new(bh); - clear_buffer_delay(bh); - clear_buffer_unwritten(bh); - clear_buffer_uptodate(bh); - zero_user(page, pos, range_to_discard); - BUFFER_TRACE(bh, "Buffer discarded"); - goto next; - } - - /* - * If this block is not completely contained in the range - * to be discarded, then it is not going to be released. Because - * we need to keep this block, we need to make sure this part - * of the page is uptodate before we modify it by writeing - * partial zeros on it. - */ - if (!buffer_mapped(bh)) { - /* - * Buffer head must be mapped before we can read - * from the block - */ - BUFFER_TRACE(bh, "unmapped"); - ext4_get_block(inode, iblock, bh, 0); - /* unmapped? It's a hole - nothing to do */ - if (!buffer_mapped(bh)) { - BUFFER_TRACE(bh, "still unmapped"); - goto next; - } - } - - /* Ok, it's mapped. Make sure it's up-to-date */ - if (PageUptodate(page)) - set_buffer_uptodate(bh); - - if (!buffer_uptodate(bh)) { - err = -EIO; - ll_rw_block(READ, 1, &bh); - wait_on_buffer(bh); - /* Uhhuh. Read error. Complain and punt.*/ - if (!buffer_uptodate(bh)) - goto next; - } - - if (ext4_should_journal_data(inode)) { - BUFFER_TRACE(bh, "get write access"); - err = ext4_journal_get_write_access(handle, bh); - if (err) - goto next; - } - - zero_user(page, pos, range_to_discard); - - err = 0; - if (ext4_should_journal_data(inode)) { - err = ext4_handle_dirty_metadata(handle, inode, bh); - } else - mark_buffer_dirty(bh); - - BUFFER_TRACE(bh, "Partial buffer zeroed"); -next: - bh = bh->b_this_page; - iblock++; - pos += range_to_discard; - } - - return err; -} - /* * ext4_block_truncate_page() zeroes out a mapping from file offset `from' * up to the end of the block which corresponds to `from'. -- 1.7.7.6 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org