diff options
| -rw-r--r-- | fs/jffs2/file.c | 105 |
1 files changed, 66 insertions, 39 deletions
diff --git a/fs/jffs2/file.c b/fs/jffs2/file.c index c2530197be0..023a17539dd 100644 --- a/fs/jffs2/file.c +++ b/fs/jffs2/file.c @@ -19,10 +19,12 @@ #include <linux/jffs2.h> #include "nodelist.h" -static int jffs2_commit_write (struct file *filp, struct page *pg, - unsigned start, unsigned end); -static int jffs2_prepare_write (struct file *filp, struct page *pg, - unsigned start, unsigned end); +static int jffs2_write_end(struct file *filp, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *pg, void *fsdata); +static int jffs2_write_begin(struct file *filp, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata); static int jffs2_readpage (struct file *filp, struct page *pg); int jffs2_fsync(struct file *filp, struct dentry *dentry, int datasync) @@ -65,8 +67,8 @@ const struct inode_operations jffs2_file_inode_operations = const struct address_space_operations jffs2_file_address_operations = { .readpage = jffs2_readpage, - .prepare_write =jffs2_prepare_write, - .commit_write = jffs2_commit_write + .write_begin = jffs2_write_begin, + .write_end = jffs2_write_end, }; static int jffs2_do_readpage_nolock (struct inode *inode, struct page *pg) @@ -119,15 +121,23 @@ static int jffs2_readpage (struct file *filp, struct page *pg) return ret; } -static int jffs2_prepare_write (struct file *filp, struct page *pg, - unsigned start, unsigned end) +static int jffs2_write_begin(struct file *filp, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) { - struct inode *inode = pg->mapping->host; + struct page *pg; + struct inode *inode = mapping->host; struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); - uint32_t pageofs = pg->index << PAGE_CACHE_SHIFT; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; + uint32_t pageofs = pos & (PAGE_CACHE_SIZE - 1); int ret = 0; - D1(printk(KERN_DEBUG "jffs2_prepare_write()\n")); + pg = __grab_cache_page(mapping, index); + if (!pg) + return -ENOMEM; + *pagep = pg; + + D1(printk(KERN_DEBUG "jffs2_write_begin()\n")); if (pageofs > inode->i_size) { /* Make new hole frag from old EOF to new page */ @@ -142,7 +152,7 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg, ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len, ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); if (ret) - return ret; + goto out_page; down(&f->sem); memset(&ri, 0, sizeof(ri)); @@ -172,7 +182,7 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg, ret = PTR_ERR(fn); jffs2_complete_reservation(c); up(&f->sem); - return ret; + goto out_page; } ret = jffs2_add_full_dnode_to_inode(c, f, fn); if (f->metadata) { @@ -181,65 +191,79 @@ static int jffs2_prepare_write (struct file *filp, struct page *pg, f->metadata = NULL; } if (ret) { - D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in prepare_write, returned %d\n", ret)); + D1(printk(KERN_DEBUG "Eep. add_full_dnode_to_inode() failed in write_begin, returned %d\n", ret)); jffs2_mark_node_obsolete(c, fn->raw); jffs2_free_full_dnode(fn); jffs2_complete_reservation(c); up(&f->sem); - return ret; + goto out_page; } jffs2_complete_reservation(c); inode->i_size = pageofs; up(&f->sem); } - /* Read in the page if it wasn't already present, unless it's a whole page */ - if (!PageUptodate(pg) && (start || end < PAGE_CACHE_SIZE)) { + /* + * Read in the page if it wasn't already present. Cannot optimize away + * the whole page write case until jffs2_write_end can handle the + * case of a short-copy. + */ + if (!PageUptodate(pg)) { down(&f->sem); ret = jffs2_do_readpage_nolock(inode, pg); up(&f->sem); + if (ret) + goto out_page; } - D1(printk(KERN_DEBUG "end prepare_write(). pg->flags %lx\n", pg->flags)); + D1(printk(KERN_DEBUG "end write_begin(). pg->flags %lx\n", pg->flags)); + return ret; + +out_page: + unlock_page(pg); + page_cache_release(pg); return ret; } -static int jffs2_commit_write (struct file *filp, struct page *pg, - unsigned start, unsigned end) +static int jffs2_write_end(struct file *filp, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *pg, void *fsdata) { /* Actually commit the write from the page cache page we're looking at. * For now, we write the full page out each time. It sucks, but it's simple */ - struct inode *inode = pg->mapping->host; + struct inode *inode = mapping->host; struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode); struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb); struct jffs2_raw_inode *ri; + unsigned start = pos & (PAGE_CACHE_SIZE - 1); + unsigned end = start + copied; unsigned aligned_start = start & ~3; int ret = 0; uint32_t writtenlen = 0; - D1(printk(KERN_DEBUG "jffs2_commit_write(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", + D1(printk(KERN_DEBUG "jffs2_write_end(): ino #%lu, page at 0x%lx, range %d-%d, flags %lx\n", inode->i_ino, pg->index << PAGE_CACHE_SHIFT, start, end, pg->flags)); + /* We need to avoid deadlock with page_cache_read() in + jffs2_garbage_collect_pass(). So the page must be + up to date to prevent page_cache_read() from trying + to re-lock it. */ + BUG_ON(!PageUptodate(pg)); + if (end == PAGE_CACHE_SIZE) { - if (!start) { - /* We need to avoid deadlock with page_cache_read() in - jffs2_garbage_collect_pass(). So we have to mark the - page up to date, to prevent page_cache_read() from - trying to re-lock it. */ - SetPageUptodate(pg); - } else { - /* When writing out the end of a page, write out the - _whole_ page. This helps to reduce the number of - nodes in files which have many short writes, like - syslog files. */ - start = aligned_start = 0; - } + /* When writing out the end of a page, write out the + _whole_ page. This helps to reduce the number of + nodes in files which have many short writes, like + syslog files. */ + start = aligned_start = 0; } ri = jffs2_alloc_raw_inode(); if (!ri) { - D1(printk(KERN_DEBUG "jffs2_commit_write(): Allocation of raw inode failed\n")); + D1(printk(KERN_DEBUG "jffs2_write_end(): Allocation of raw inode failed\n")); + unlock_page(pg); + page_cache_release(pg); return -ENOMEM; } @@ -287,11 +311,14 @@ static int jffs2_commit_write (struct file *filp, struct page *pg, /* generic_file_write has written more to the page cache than we've actually written to the medium. Mark the page !Uptodate so that it gets reread */ - D1(printk(KERN_DEBUG "jffs2_commit_write(): Not all bytes written. Marking page !uptodate\n")); + D1(printk(KERN_DEBUG "jffs2_write_end(): Not all bytes written. Marking page !uptodate\n")); SetPageError(pg); ClearPageUptodate(pg); } - D1(printk(KERN_DEBUG "jffs2_commit_write() returning %d\n",start+writtenlen==end?0:ret)); - return start+writtenlen==end?0:ret; + D1(printk(KERN_DEBUG "jffs2_write_end() returning %d\n", + writtenlen > 0 ? writtenlen : ret)); + unlock_page(pg); + page_cache_release(pg); + return writtenlen > 0 ? writtenlen : ret; } |