Cc: zippel@xxxxxxxxxxxxxx
Cc: Linux Filesystems <linux-fsdevel@xxxxxxxxxxxxxxx>
Signed-off-by: Nick Piggin <npiggin@xxxxxxx>
fs/affs/file.c | 106 +++++++++++++++++++++++++++++++--------------------------
1 file changed, 58 insertions(+), 48 deletions(-)
Index: linux-2.6/fs/affs/file.c
===================================================================
--- linux-2.6.orig/fs/affs/file.c
+++ linux-2.6/fs/affs/file.c
@@ -395,25 +395,33 @@ static int affs_writepage(struct page *p
{
return block_write_full_page(page, affs_get_block, wbc);
}
+
static int affs_readpage(struct file *file, struct page *page)
{
return block_read_full_page(page, affs_get_block);
}
-static int affs_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to)
-{
- return cont_prepare_write(page, from, to, affs_get_block,
- &AFFS_I(page->mapping->host)->mmu_private);
+
+static int affs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ *pagep = NULL;
+ return cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
+ affs_get_block,
+ &AFFS_I(mapping->host)->mmu_private);
}
+
static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping,block,affs_get_block);
}
+
const struct address_space_operations affs_aops = {
.readpage = affs_readpage,
.writepage = affs_writepage,
.sync_page = block_sync_page,
- .prepare_write = affs_prepare_write,
- .commit_write = generic_commit_write,
+ .write_begin = affs_write_begin,
+ .write_end = generic_write_end,
.bmap = _affs_bmap
};
@@ -603,58 +611,65 @@ affs_readpage_ofs(struct file *file, str
return err;
}
-static int affs_prepare_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
-{
- struct inode *inode = page->mapping->host;
- u32 size, offset;
- u32 tmp;
+static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct inode *inode = mapping->host;
+ struct page *page;
+ pgoff_t index;
int err = 0;
- pr_debug("AFFS: prepare_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
- offset = page->index << PAGE_CACHE_SHIFT;
- if (offset + from > AFFS_I(inode)->mmu_private) {
- err = affs_extent_file_ofs(inode, offset + from);
+ pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len);
+ if (pos > AFFS_I(inode)->mmu_private) {
+ /* XXX: this probably leaves a too-big i_size in case of
+ * failure. Should really be updating i_size at write_end time
+ */
+ err = affs_extent_file_ofs(inode, pos);
if (err)
return err;
}
- size = inode->i_size;
+
+ index = pos >> PAGE_CACHE_SHIFT;
+ page = __grab_cache_page(mapping, index);
+ if (!page)
+ return -ENOMEM;
+ *pagep = page;
if (PageUptodate(page))
return 0;
- if (from) {
- err = affs_do_readpage_ofs(file, page, 0, from);
- if (err)
- return err;
- }
- if (to < PAGE_CACHE_SIZE) {
- char *kaddr = kmap_atomic(page, KM_USER0);
-
- memset(kaddr + to, 0, PAGE_CACHE_SIZE - to);
- flush_dcache_page(page);
- kunmap_atomic(kaddr, KM_USER0);
- if (size > offset + to) {
- if (size < offset + PAGE_CACHE_SIZE)
- tmp = size & ~PAGE_CACHE_MASK;
- else
- tmp = PAGE_CACHE_SIZE;
- err = affs_do_readpage_ofs(file, page, to, tmp);
- }
+ /* XXX: inefficient but safe in the face of short writes */
+ err = affs_do_readpage_ofs(file, page, 0, PAGE_CACHE_SIZE);
+ if (err) {
+ unlock_page(page);
+ page_cache_release(page);
}
return err;
}
-static int affs_commit_write_ofs(struct file *file, struct page *page, unsigned from, unsigned to)
+static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
{
- struct inode *inode = page->mapping->host;
+ struct inode *inode = mapping->host;
struct super_block *sb = inode->i_sb;
struct buffer_head *bh, *prev_bh;
char *data;
u32 bidx, boff, bsize;
+ unsigned from, to;
u32 tmp;
int written;
- pr_debug("AFFS: commit_write(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
+ from = pos & (PAGE_CACHE_SIZE - 1);
+ to = pos + len;
+ /*
+ * XXX: not sure if this can handle short copies (len < copied), but
+ * we don't have to, because the page should always be uptodate here,
+ * due to write_begin.
+ */
+
+ pr_debug("AFFS: write_begin(%u, %llu, %llu)\n", (u32)inode->i_ino, (unsigned long long)pos, (unsigned long long)pos + len);
bsize = AFFS_SB(sb)->s_data_blksize;
data = page_address(page);
@@ -765,8 +780,8 @@ const struct address_space_operations af
.readpage = affs_readpage_ofs,
//.writepage = affs_writepage_ofs,
//.sync_page = affs_sync_page_ofs,
- .prepare_write = affs_prepare_write_ofs,
- .commit_write = affs_commit_write_ofs
+ .write_begin = affs_write_begin_ofs,
+ .write_end = affs_write_end_ofs
};
/* Free any preallocated blocks. */
@@ -809,18 +824,13 @@ affs_truncate(struct inode *inode)
if (inode->i_size > AFFS_I(inode)->mmu_private) {
struct address_space *mapping = inode->i_mapping;
struct page *page;
- u32 size = inode->i_size - 1;
+ void *fsdata;
+ u32 size = inode->i_size;
int res;
- page = grab_cache_page(mapping, size >> PAGE_CACHE_SHIFT);
- if (!page)
- return;
- size = (size & (PAGE_CACHE_SIZE - 1)) + 1;
- res = mapping->a_ops->prepare_write(NULL, page, size, size);
+ res = mapping->a_ops->write_begin(NULL, mapping, size, 0, 0, &page, &fsdata);
if (!res)
- res = mapping->a_ops->commit_write(NULL, page, size, size);
- unlock_page(page);
- page_cache_release(page);
+ res = mapping->a_ops->write_end(NULL, mapping, size, 0, 0, page, fsdata);
mark_inode_dirty(inode);
return;
} else if (inode->i_size == AFFS_I(inode)->mmu_private)
--
-
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