/*
* This does the "real" work of the write. We must allocate and lock the
* page to be sent back to the generic routine, which then copies the
* data from user space.
*
* If the writer ends up delaying the write, the writer needs to
* increment the page use counts until he is done with the page.
*/
static int nfs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
pgoff_t index;
struct page *page;
index = pos >> PAGE_CACHE_SHIFT;
dfprintk(PAGECACHE, "NFS: write_begin(%s/%s(%ld), %u@%lld)\n",
file->f_path.dentry->d_parent->d_name.name,
file->f_path.dentry->d_name.name,
mapping->host->i_ino, len, (long long) pos);
page = __grab_cache_page(mapping, index);
if (!page)
return -ENOMEM;
*pagep = page;
ret = nfs_flush_incompatible(file, page);
if (ret) {
unlock_page(page);
page_cache_release(page);
}
return ret;
}
/*
* This does the "real" work of the write. We must allocate and lock the
* page to be sent back to the generic routine, which then copies the
* data from user space.
*
* If the writer ends up delaying the write, the writer needs to
* increment the page use counts until he is done with the page.
*/
static int nfs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
pgoff_t index;
struct page *page;
index = pos >> PAGE_CACHE_SHIFT;
page = __grab_cache_page(mapping, index);
if (!page)
return -ENOMEM;
*pagep = page;
ret = nfs_flush_incompatible(file, page);
if (ret) {
unlock_page(page);
page_cache_release(page);
}
return ret;
}
int j4fs_write_begin(struct file *filp, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
struct page *pg = NULL;
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
uint32_t offset = pos & (PAGE_CACHE_SIZE - 1);
uint32_t to = offset + len;
int ret = 0;
int space_held = 0;
if(j4fs_panic==1) {
J4FS_T(J4FS_TRACE_ALWAYS,("%s %d: j4fs panic\n",__FUNCTION__,__LINE__));
return -ENOSPC;
}
J4FS_T(J4FS_TRACE_FS, ("start j4fs_write_begin\n"));
if(to>PAGE_CACHE_SIZE) {
J4FS_T(J4FS_TRACE_ALWAYS,("%s %d: page size overflow(pos,index,offset,len,to)=(%d,%d,%d,%d,%d)\n",__FUNCTION__,__LINE__,pos,index,offset,len,to));
j4fs_panic("page size overflow");
return -ENOSPC;
}
/* Get a page */
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 28)
pg = grab_cache_page_write_begin(mapping, index, flags);
#else
pg = __grab_cache_page(mapping, index);
#endif
*pagep = pg;
if (!pg) {
ret = -ENOMEM;
goto out;
}
/* Get fs space */
space_held = j4fs_hold_space(PAGE_CACHE_SIZE);
if (!space_held) {
ret = -ENOSPC;
goto out;
}
/* Update page if required */
if (!Page_Uptodate(pg) && (offset || to < PAGE_CACHE_SIZE))
ret = j4fs_readpage_nolock(filp, pg);
if (ret)
goto out;
/* Happy path return */
J4FS_T(J4FS_TRACE_FS, ("end j4fs_write_begin - ok\n"));
return 0;
out:
J4FS_T(J4FS_TRACE_FS, ("end j4fs_write_begin fail returning %d\n", ret));
if (pg) {
unlock_page(pg);
page_cache_release(pg);
}
return ret;
}
/*
* This does the "real" work of the write. The generic routine has
* allocated the page, locked it, done all the page alignment stuff
* calculations etc. Now we should just copy the data from user
* space and write it back to the real medium..
*
* If the writer ends up delaying the write, the writer needs to
* increment the page use counts until he is done with the page.
*/
static int smb_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
*pagep = __grab_cache_page(mapping, index);
if (!*pagep)
return -ENOMEM;
return 0;
}
static int smb_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
int status;
unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
lock_kernel();
status = smb_updatepage(file, page, offset, copied);
unlock_kernel();
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 page *pg;
struct inode *inode = mapping->host;
struct jffs2_inode_info *f = JFFS2_INODE_INFO(inode);
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
uint32_t pageofs = index << PAGE_CACHE_SHIFT;
int ret = 0;
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 */
struct jffs2_sb_info *c = JFFS2_SB_INFO(inode->i_sb);
struct jffs2_raw_inode ri;
struct jffs2_full_dnode *fn;
uint32_t alloc_len;
D1(printk(KERN_DEBUG "Writing new hole frag 0x%x-0x%x between current EOF and new page\n",
(unsigned int)inode->i_size, pageofs));
ret = jffs2_reserve_space(c, sizeof(ri), &alloc_len,
ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE);
if (ret)
goto out_page;
down(&f->sem);
memset(&ri, 0, sizeof(ri));
ri.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK);
ri.nodetype = cpu_to_je16(JFFS2_NODETYPE_INODE);
ri.totlen = cpu_to_je32(sizeof(ri));
ri.hdr_crc = cpu_to_je32(crc32(0, &ri, sizeof(struct jffs2_unknown_node)-4));
ri.ino = cpu_to_je32(f->inocache->ino);
ri.version = cpu_to_je32(++f->highest_version);
ri.mode = cpu_to_jemode(inode->i_mode);
ri.uid = cpu_to_je16(inode->i_uid);
ri.gid = cpu_to_je16(inode->i_gid);
ri.isize = cpu_to_je32(max((uint32_t)inode->i_size, pageofs));
ri.atime = ri.ctime = ri.mtime = cpu_to_je32(get_seconds());
ri.offset = cpu_to_je32(inode->i_size);
ri.dsize = cpu_to_je32(pageofs - inode->i_size);
ri.csize = cpu_to_je32(0);
ri.compr = JFFS2_COMPR_ZERO;
ri.node_crc = cpu_to_je32(crc32(0, &ri, sizeof(ri)-8));
ri.data_crc = cpu_to_je32(0);
fn = jffs2_write_dnode(c, f, &ri, NULL, 0, ALLOC_NORMAL);
if (IS_ERR(fn)) {
ret = PTR_ERR(fn);
jffs2_complete_reservation(c);
up(&f->sem);
goto out_page;
}
ret = jffs2_add_full_dnode_to_inode(c, f, fn);
if (f->metadata) {
jffs2_mark_node_obsolete(c, f->metadata->raw);
jffs2_free_full_dnode(f->metadata);
f->metadata = NULL;
}
if (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);
goto out_page;
}
jffs2_complete_reservation(c);
inode->i_size = pageofs;
up(&f->sem);
}
/*
* 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 write_begin(). pg->flags %lx\n", pg->flags));
return ret;
out_page:
unlock_page(pg);
page_cache_release(pg);
return ret;
}
static int gfs2_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
struct gfs2_inode *ip = GFS2_I(mapping->host);
struct gfs2_sbd *sdp = GFS2_SB(mapping->host);
unsigned int data_blocks, ind_blocks, rblocks;
int alloc_required;
int error = 0;
struct gfs2_alloc *al;
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
unsigned from = pos & (PAGE_CACHE_SIZE - 1);
unsigned to = from + len;
struct page *page;
gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, GL_ATIME, &ip->i_gh);
error = gfs2_glock_nq_atime(&ip->i_gh);
if (unlikely(error))
goto out_uninit;
gfs2_write_calc_reserv(ip, len, &data_blocks, &ind_blocks);
error = gfs2_write_alloc_required(ip, pos, len, &alloc_required);
if (error)
goto out_unlock;
if (alloc_required) {
al = gfs2_alloc_get(ip);
error = gfs2_quota_lock(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE);
if (error)
goto out_alloc_put;
error = gfs2_quota_check(ip, ip->i_inode.i_uid, ip->i_inode.i_gid);
if (error)
goto out_qunlock;
al->al_requested = data_blocks + ind_blocks;
error = gfs2_inplace_reserve(ip);
if (error)
goto out_qunlock;
}
rblocks = RES_DINODE + ind_blocks;
if (gfs2_is_jdata(ip))
rblocks += data_blocks ? data_blocks : 1;
if (ind_blocks || data_blocks)
rblocks += RES_STATFS + RES_QUOTA;
error = gfs2_trans_begin(sdp, rblocks,
PAGE_CACHE_SIZE/sdp->sd_sb.sb_bsize);
if (error)
goto out_trans_fail;
error = -ENOMEM;
page = __grab_cache_page(mapping, index);
*pagep = page;
if (unlikely(!page))
goto out_endtrans;
if (gfs2_is_stuffed(ip)) {
error = 0;
if (pos + len > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) {
error = gfs2_unstuff_dinode(ip, page);
if (error == 0)
goto prepare_write;
} else if (!PageUptodate(page)) {
error = stuffed_readpage(ip, page);
}
goto out;
}
prepare_write:
error = block_prepare_write(page, from, to, gfs2_block_map);
out:
if (error == 0)
return 0;
page_cache_release(page);
if (pos + len > ip->i_inode.i_size)
vmtruncate(&ip->i_inode, ip->i_inode.i_size);
out_endtrans:
gfs2_trans_end(sdp);
out_trans_fail:
if (alloc_required) {
gfs2_inplace_release(ip);
out_qunlock:
gfs2_quota_unlock(ip);
out_alloc_put:
gfs2_alloc_put(ip);
}
out_unlock:
gfs2_glock_dq(&ip->i_gh);
out_uninit:
gfs2_holder_uninit(&ip->i_gh);
return error;
}