diff options
| -rw-r--r-- | fs/ext2/xip.c | 81 | ||||
| -rw-r--r-- | mm/filemap_xip.c | 23 |
2 files changed, 55 insertions, 49 deletions
diff --git a/fs/ext2/xip.c b/fs/ext2/xip.c index d44431d1a33..0aa5ac159c0 100644 --- a/fs/ext2/xip.c +++ b/fs/ext2/xip.c @@ -15,66 +15,79 @@ #include "xip.h" static inline int -__inode_direct_access(struct inode *inode, sector_t sector, unsigned long *data) { +__inode_direct_access(struct inode *inode, sector_t sector, + unsigned long *data) +{ BUG_ON(!inode->i_sb->s_bdev->bd_disk->fops->direct_access); return inode->i_sb->s_bdev->bd_disk->fops ->direct_access(inode->i_sb->s_bdev,sector,data); } +static inline int +__ext2_get_sector(struct inode *inode, sector_t offset, int create, + sector_t *result) +{ + struct buffer_head tmp; + int rc; + + memset(&tmp, 0, sizeof(struct buffer_head)); + rc = ext2_get_block(inode, offset/ (PAGE_SIZE/512), &tmp, + create); + *result = tmp.b_blocknr; + + /* did we get a sparse block (hole in the file)? */ + if (!(*result)) { + BUG_ON(create); + rc = -ENODATA; + } + + return rc; +} + int -ext2_clear_xip_target(struct inode *inode, int block) { - sector_t sector = block*(PAGE_SIZE/512); +ext2_clear_xip_target(struct inode *inode, int block) +{ + sector_t sector = block * (PAGE_SIZE/512); unsigned long data; int rc; rc = __inode_direct_access(inode, sector, &data); - if (rc) - return rc; - clear_page((void*)data); - return 0; + if (!rc) + clear_page((void*)data); + return rc; } void ext2_xip_verify_sb(struct super_block *sb) { struct ext2_sb_info *sbi = EXT2_SB(sb); - if ((sbi->s_mount_opt & EXT2_MOUNT_XIP)) { - if ((sb->s_bdev == NULL) || - sb->s_bdev->bd_disk == NULL || - sb->s_bdev->bd_disk->fops == NULL || - sb->s_bdev->bd_disk->fops->direct_access == NULL) { - sbi->s_mount_opt &= (~EXT2_MOUNT_XIP); - ext2_warning(sb, __FUNCTION__, - "ignoring xip option - not supported by bdev"); - } + if ((sbi->s_mount_opt & EXT2_MOUNT_XIP) && + !sb->s_bdev->bd_disk->fops->direct_access) { + sbi->s_mount_opt &= (~EXT2_MOUNT_XIP); + ext2_warning(sb, __FUNCTION__, + "ignoring xip option - not supported by bdev"); } } -struct page* -ext2_get_xip_page(struct address_space *mapping, sector_t blockno, +struct page * +ext2_get_xip_page(struct address_space *mapping, sector_t offset, int create) { int rc; unsigned long data; - struct buffer_head tmp; + sector_t sector; - tmp.b_state = 0; - tmp.b_blocknr = 0; - rc = ext2_get_block(mapping->host, blockno/(PAGE_SIZE/512) , &tmp, - create); + /* first, retrieve the sector number */ + rc = __ext2_get_sector(mapping->host, offset, create, §or); if (rc) - return ERR_PTR(rc); - if (tmp.b_blocknr == 0) { - /* SPARSE block */ - BUG_ON(create); - return ERR_PTR(-ENODATA); - } + goto error; + /* retrieve address of the target data */ rc = __inode_direct_access - (mapping->host,tmp.b_blocknr*(PAGE_SIZE/512) ,&data); - if (rc) - return ERR_PTR(rc); + (mapping->host, sector * (PAGE_SIZE/512), &data); + if (!rc) + return virt_to_page(data); - SetPageUptodate(virt_to_page(data)); - return virt_to_page(data); + error: + return ERR_PTR(rc); } diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c index 4553b2c5aab..8c199f53773 100644 --- a/mm/filemap_xip.c +++ b/mm/filemap_xip.c @@ -68,13 +68,12 @@ do_xip_mapping_read(struct address_space *mapping, if (unlikely(IS_ERR(page))) { if (PTR_ERR(page) == -ENODATA) { /* sparse */ - page = virt_to_page(empty_zero_page); + page = ZERO_PAGE(0); } else { desc->error = PTR_ERR(page); goto out; } - } else - BUG_ON(!PageUptodate(page)); + } /* If users can be writing to this page using arbitrary * virtual addresses, take care about potential aliasing @@ -84,8 +83,7 @@ do_xip_mapping_read(struct address_space *mapping, flush_dcache_page(page); /* - * Ok, we have the page, and it's up-to-date, so - * now we can copy it to user space... + * Ok, we have the page, so now we can copy it to user space... * * The actor routine returns how many bytes were actually used.. * NOTE! This may not be the same as how much of a user buffer @@ -164,7 +162,7 @@ EXPORT_SYMBOL_GPL(xip_file_sendfile); * xip_write * * This function walks all vmas of the address_space and unmaps the - * empty_zero_page when found at pgoff. Should it go in rmap.c? + * ZERO_PAGE when found at pgoff. Should it go in rmap.c? */ static void __xip_unmap (struct address_space * mapping, @@ -187,7 +185,7 @@ __xip_unmap (struct address_space * mapping, * We need the page_table_lock to protect us from page faults, * munmap, fork, etc... */ - pte = page_check_address(virt_to_page(empty_zero_page), mm, + pte = page_check_address(ZERO_PAGE(address), mm, address); if (!IS_ERR(pte)) { /* Nuke the page table entry. */ @@ -230,7 +228,6 @@ xip_file_nopage(struct vm_area_struct * area, page = mapping->a_ops->get_xip_page(mapping, pgoff*(PAGE_SIZE/512), 0); if (!IS_ERR(page)) { - BUG_ON(!PageUptodate(page)); return page; } if (PTR_ERR(page) != -ENODATA) @@ -245,12 +242,11 @@ xip_file_nopage(struct vm_area_struct * area, pgoff*(PAGE_SIZE/512), 1); if (IS_ERR(page)) return NULL; - BUG_ON(!PageUptodate(page)); /* unmap page at pgoff from all other vmas */ __xip_unmap(mapping, pgoff); } else { - /* not shared and writable, use empty_zero_page */ - page = virt_to_page(empty_zero_page); + /* not shared and writable, use ZERO_PAGE() */ + page = ZERO_PAGE(address); } return page; @@ -319,8 +315,6 @@ __xip_file_write(struct file *filp, const char __user *buf, break; } - BUG_ON(!PageUptodate(page)); - copied = filemap_copy_from_user(page, offset, buf, bytes); flush_dcache_page(page); if (likely(copied > 0)) { @@ -435,8 +429,7 @@ xip_truncate_page(struct address_space *mapping, loff_t from) return 0; else return PTR_ERR(page); - } else - BUG_ON(!PageUptodate(page)); + } kaddr = kmap_atomic(page, KM_USER0); memset(kaddr + offset, 0, length); kunmap_atomic(kaddr, KM_USER0); |