diff options
| -rw-r--r-- | fs/afs/file.c | 4 | ||||
| -rw-r--r-- | fs/afs/internal.h | 8 | ||||
| -rw-r--r-- | fs/afs/write.c | 131 |
3 files changed, 51 insertions, 92 deletions
diff --git a/fs/afs/file.c b/fs/afs/file.c index 525f7c56e06..a3901769a96 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -50,8 +50,8 @@ const struct address_space_operations afs_fs_aops = { .launder_page = afs_launder_page, .releasepage = afs_releasepage, .invalidatepage = afs_invalidatepage, - .prepare_write = afs_prepare_write, - .commit_write = afs_commit_write, + .write_begin = afs_write_begin, + .write_end = afs_write_end, .writepage = afs_writepage, .writepages = afs_writepages, }; diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 3cb6920ff30..67f259d99cd 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -728,8 +728,12 @@ extern int afs_volume_release_fileserver(struct afs_vnode *, */ extern int afs_set_page_dirty(struct page *); extern void afs_put_writeback(struct afs_writeback *); -extern int afs_prepare_write(struct file *, struct page *, unsigned, unsigned); -extern int afs_commit_write(struct file *, struct page *, unsigned, unsigned); +extern int afs_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata); +extern int afs_write_end(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata); extern int afs_writepage(struct page *, struct writeback_control *); extern int afs_writepages(struct address_space *, struct writeback_control *); extern int afs_write_inode(struct inode *, int); diff --git a/fs/afs/write.c b/fs/afs/write.c index 065b4e10681..d6b85dab35f 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -84,15 +84,23 @@ void afs_put_writeback(struct afs_writeback *wb) * partly or wholly fill a page that's under preparation for writing */ static int afs_fill_page(struct afs_vnode *vnode, struct key *key, - unsigned start, unsigned len, struct page *page) + loff_t pos, unsigned len, struct page *page) { + loff_t i_size; + unsigned eof; int ret; - _enter(",,%u,%u", start, len); + _enter(",,%llu,%u", (unsigned long long)pos, len); - ASSERTCMP(start + len, <=, PAGE_SIZE); + ASSERTCMP(len, <=, PAGE_CACHE_SIZE); - ret = afs_vnode_fetch_data(vnode, key, start, len, page); + i_size = i_size_read(&vnode->vfs_inode); + if (pos + len > i_size) + eof = i_size; + else + eof = PAGE_CACHE_SIZE; + + ret = afs_vnode_fetch_data(vnode, key, 0, eof, page); if (ret < 0) { if (ret == -ENOENT) { _debug("got NOENT from server" @@ -107,109 +115,55 @@ static int afs_fill_page(struct afs_vnode *vnode, struct key *key, } /* - * prepare a page for being written to - */ -static int afs_prepare_page(struct afs_vnode *vnode, struct page *page, - struct key *key, unsigned offset, unsigned to) -{ - unsigned eof, tail, start, stop, len; - loff_t i_size, pos; - void *p; - int ret; - - _enter(""); - - if (offset == 0 && to == PAGE_SIZE) - return 0; - - p = kmap_atomic(page, KM_USER0); - - i_size = i_size_read(&vnode->vfs_inode); - pos = (loff_t) page->index << PAGE_SHIFT; - if (pos >= i_size) { - /* partial write, page beyond EOF */ - _debug("beyond"); - if (offset > 0) - memset(p, 0, offset); - if (to < PAGE_SIZE) - memset(p + to, 0, PAGE_SIZE - to); - kunmap_atomic(p, KM_USER0); - return 0; - } - - if (i_size - pos >= PAGE_SIZE) { - /* partial write, page entirely before EOF */ - _debug("before"); - tail = eof = PAGE_SIZE; - } else { - /* partial write, page overlaps EOF */ - eof = i_size - pos; - _debug("overlap %u", eof); - tail = max(eof, to); - if (tail < PAGE_SIZE) - memset(p + tail, 0, PAGE_SIZE - tail); - if (offset > eof) - memset(p + eof, 0, PAGE_SIZE - eof); - } - - kunmap_atomic(p, KM_USER0); - - ret = 0; - if (offset > 0 || eof > to) { - /* need to fill one or two bits that aren't going to be written - * (cover both fillers in one read if there are two) */ - start = (offset > 0) ? 0 : to; - stop = (eof > to) ? eof : offset; - len = stop - start; - _debug("wr=%u-%u av=0-%u rd=%u@%u", - offset, to, eof, start, len); - ret = afs_fill_page(vnode, key, start, len, page); - } - - _leave(" = %d", ret); - return ret; -} - -/* * prepare to perform part of a write to a page - * - the caller holds the page locked, preventing it from being written out or - * modified by anyone else */ -int afs_prepare_write(struct file *file, struct page *page, - unsigned offset, unsigned to) +int afs_write_begin(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned flags, + struct page **pagep, void **fsdata) { struct afs_writeback *candidate, *wb; struct afs_vnode *vnode = AFS_FS_I(file->f_dentry->d_inode); + struct page *page; struct key *key = file->private_data; - pgoff_t index; + unsigned from = pos & (PAGE_CACHE_SIZE - 1); + unsigned to = from + len; + pgoff_t index = pos >> PAGE_CACHE_SHIFT; int ret; _enter("{%x:%u},{%lx},%u,%u", - vnode->fid.vid, vnode->fid.vnode, page->index, offset, to); + vnode->fid.vid, vnode->fid.vnode, index, from, to); candidate = kzalloc(sizeof(*candidate), GFP_KERNEL); if (!candidate) return -ENOMEM; candidate->vnode = vnode; - candidate->first = candidate->last = page->index; - candidate->offset_first = offset; + candidate->first = candidate->last = index; + candidate->offset_first = from; candidate->to_last = to; candidate->usage = 1; candidate->state = AFS_WBACK_PENDING; init_waitqueue_head(&candidate->waitq); + page = __grab_cache_page(mapping, index); + if (!page) { + kfree(candidate); + return -ENOMEM; + } + *pagep = page; + /* page won't leak in error case: it eventually gets cleaned off LRU */ + if (!PageUptodate(page)) { _debug("not up to date"); - ret = afs_prepare_page(vnode, page, key, offset, to); + ret = afs_fill_page(vnode, key, pos, len, page); if (ret < 0) { kfree(candidate); _leave(" = %d [prep]", ret); return ret; } + SetPageUptodate(page); } try_again: - index = page->index; spin_lock(&vnode->writeback_lock); /* see if this page is already pending a writeback under a suitable key @@ -242,8 +196,8 @@ try_again: subsume_in_current_wb: _debug("subsume"); ASSERTRANGE(wb->first, <=, index, <=, wb->last); - if (index == wb->first && offset < wb->offset_first) - wb->offset_first = offset; + if (index == wb->first && from < wb->offset_first) + wb->offset_first = from; if (index == wb->last && to > wb->to_last) wb->to_last = to; spin_unlock(&vnode->writeback_lock); @@ -289,17 +243,17 @@ flush_conflicting_wb: /* * finalise part of a write to a page */ -int afs_commit_write(struct file *file, struct page *page, - unsigned offset, unsigned to) +int afs_write_end(struct file *file, struct address_space *mapping, + loff_t pos, unsigned len, unsigned copied, + struct page *page, void *fsdata) { struct afs_vnode *vnode = AFS_FS_I(file->f_dentry->d_inode); loff_t i_size, maybe_i_size; - _enter("{%x:%u},{%lx},%u,%u", - vnode->fid.vid, vnode->fid.vnode, page->index, offset, to); + _enter("{%x:%u},{%lx}", + vnode->fid.vid, vnode->fid.vnode, page->index); - maybe_i_size = (loff_t) page->index << PAGE_SHIFT; - maybe_i_size += to; + maybe_i_size = pos + copied; i_size = i_size_read(&vnode->vfs_inode); if (maybe_i_size > i_size) { @@ -310,12 +264,13 @@ int afs_commit_write(struct file *file, struct page *page, spin_unlock(&vnode->writeback_lock); } - SetPageUptodate(page); set_page_dirty(page); if (PageDirty(page)) _debug("dirtied"); + unlock_page(page); + page_cache_release(page); - return 0; + return copied; } /* |