* ->mmap_sem
* ->lock_page (access_process_vm)
*
- * ->mmap_sem
- * ->i_mutex (msync)
+ * ->i_mutex (generic_file_buffered_write)
+ * ->mmap_sem (fault_in_pages_readable->do_page_fault)
*
* ->i_mutex
* ->i_alloc_sem (various)
}
#ifdef CONFIG_NUMA
-struct page *page_cache_alloc(struct address_space *x)
+struct page *__page_cache_alloc(gfp_t gfp)
{
if (cpuset_do_page_mem_spread()) {
int n = cpuset_mem_spread_node();
- return alloc_pages_node(n, mapping_gfp_mask(x), 0);
+ return alloc_pages_node(n, gfp, 0);
}
- return alloc_pages(mapping_gfp_mask(x), 0);
+ return alloc_pages(gfp, 0);
}
-EXPORT_SYMBOL(page_cache_alloc);
+EXPORT_SYMBOL(__page_cache_alloc);
+#endif
-struct page *page_cache_alloc_cold(struct address_space *x)
+static int __sleep_on_page_lock(void *word)
{
- if (cpuset_do_page_mem_spread()) {
- int n = cpuset_mem_spread_node();
- return alloc_pages_node(n, mapping_gfp_mask(x)|__GFP_COLD, 0);
- }
- return alloc_pages(mapping_gfp_mask(x)|__GFP_COLD, 0);
+ io_schedule();
+ return 0;
}
-EXPORT_SYMBOL(page_cache_alloc_cold);
-#endif
/*
* In order to wait for pages to become available there must be
EXPORT_SYMBOL(__lock_page);
/*
- * Note completion of filesystem specific page synchronisation
- *
- * This is used to allow a page to be written to a filesystem cache in the
- * background without holding up the completion of readpage
+ * Variant of lock_page that does not require the caller to hold a reference
+ * on the page's mapping.
*/
-void fastcall end_page_fs_misc(struct page *page)
+void fastcall __lock_page_nosync(struct page *page)
{
- smp_mb__before_clear_bit();
- if (!TestClearPageFsMisc(page))
- BUG();
- smp_mb__after_clear_bit();
- __wake_up_bit(page_waitqueue(page), &page->flags, PG_fs_misc);
+ DEFINE_WAIT_BIT(wait, &page->flags, PG_locked);
+ __wait_on_bit_lock(page_waitqueue(page), &wait, __sleep_on_page_lock,
+ TASK_UNINTERRUPTIBLE);
}
-EXPORT_SYMBOL(end_page_fs_misc);
-
/**
* find_get_page - find and get a page reference
* @mapping: the address_space to search
* @offset: the page index
*
- * A rather lightweight function, finding and getting a reference to a
- * hashed page atomically.
+ * Is there a pagecache struct page at the given (mapping, offset) tuple?
+ * If yes, increment its refcount and return it; if no, return NULL.
*/
struct page * find_get_page(struct address_space *mapping, unsigned long offset)
{
grab_cache_page_nowait(struct address_space *mapping, unsigned long index)
{
struct page *page = find_get_page(mapping, index);
- gfp_t gfp_mask;
if (page) {
if (!TestSetPageLocked(page))
page_cache_release(page);
return NULL;
}
- gfp_mask = mapping_gfp_mask(mapping) & ~__GFP_FS;
- page = alloc_pages(gfp_mask, 0);
- if (page && add_to_page_cache_lru(page, mapping, index, gfp_mask)) {
+ page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~__GFP_FS);
+ if (page && add_to_page_cache_lru(page, mapping, index, GFP_KERNEL)) {
page_cache_release(page);
page = NULL;
}
struct file *filp,
loff_t *ppos,
read_descriptor_t *desc,
- read_actor_t actor,
- int nonblock)
+ read_actor_t actor)
{
struct inode *inode = mapping->host;
unsigned long index;
unsigned long last_index;
unsigned long next_index;
unsigned long prev_index;
+ unsigned int prev_offset;
loff_t isize;
struct page *cached_page;
int error;
index = *ppos >> PAGE_CACHE_SHIFT;
next_index = index;
prev_index = ra.prev_page;
+ prev_offset = ra.offset;
last_index = (*ppos + desc->count + PAGE_CACHE_SIZE-1) >> PAGE_CACHE_SHIFT;
offset = *ppos & ~PAGE_CACHE_MASK;
find_page:
page = find_get_page(mapping, index);
if (unlikely(page == NULL)) {
- if (nonblock) {
- desc->error = -EWOULDBLOCKIO;
- break;
- }
handle_ra_miss(mapping, &ra, index);
goto no_cached_page;
}
- if (!PageUptodate(page)) {
- if (nonblock) {
- page_cache_release(page);
- desc->error = -EWOULDBLOCKIO;
- break;
- }
+ if (!PageUptodate(page))
goto page_not_up_to_date;
- }
page_ok:
/* If users can be writing to this page using arbitrary
flush_dcache_page(page);
/*
- * When (part of) the same page is read multiple times
- * in succession, only mark it as accessed the first time.
+ * When a sequential read accesses a page several times,
+ * only mark it as accessed the first time.
*/
- if (prev_index != index)
+ if (prev_index != index || offset != prev_offset)
mark_page_accessed(page);
prev_index = index;
offset += ret;
index += offset >> PAGE_CACHE_SHIFT;
offset &= ~PAGE_CACHE_MASK;
+ prev_offset = ra.offset = offset;
page_cache_release(page);
if (ret == nr && desc->count)
/* Get exclusive access to the page ... */
lock_page(page);
- /* Did it get unhashed before we got the lock? */
+ /* Did it get truncated before we got the lock? */
if (!page->mapping) {
unlock_page(page);
page_cache_release(page);
}
/**
- * __generic_file_aio_read - generic filesystem read routine
+ * generic_file_aio_read - generic filesystem read routine
* @iocb: kernel I/O control block
* @iov: io vector request
* @nr_segs: number of segments in the iovec
- * @ppos: current file position
+ * @pos: current file position
*
* This is the "read()" routine for all filesystems
* that can use the page cache directly.
*/
ssize_t
-__generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t *ppos)
+generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
{
struct file *filp = iocb->ki_filp;
ssize_t retval;
unsigned long seg;
size_t count;
+ loff_t *ppos = &iocb->ki_pos;
count = 0;
for (seg = 0; seg < nr_segs; seg++) {
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (filp->f_flags & O_DIRECT) {
- loff_t pos = *ppos, size;
+ loff_t size;
struct address_space *mapping;
struct inode *inode;
if (pos < size) {
retval = generic_file_direct_IO(READ, iocb,
iov, pos, nr_segs);
- if (retval > 0 && !is_sync_kiocb(iocb))
- retval = -EIOCBQUEUED;
if (retval > 0)
*ppos = pos + retval;
}
- file_accessed(filp);
- goto out;
+ if (likely(retval != 0)) {
+ file_accessed(filp);
+ goto out;
+ }
}
retval = 0;
if (desc.count == 0)
continue;
desc.error = 0;
- do_generic_file_read(filp,ppos,&desc,file_read_actor,0);
+ do_generic_file_read(filp,ppos,&desc,file_read_actor);
retval += desc.written;
if (desc.error) {
retval = retval ?: desc.error;
out:
return retval;
}
-EXPORT_SYMBOL(__generic_file_aio_read);
-
-ssize_t
-generic_file_aio_read(struct kiocb *iocb, char __user *buf, size_t count, loff_t pos)
-{
- struct iovec local_iov = { .iov_base = buf, .iov_len = count };
-
- BUG_ON(iocb->ki_pos != pos);
- return __generic_file_aio_read(iocb, &local_iov, 1, &iocb->ki_pos);
-}
EXPORT_SYMBOL(generic_file_aio_read);
-ssize_t
-generic_file_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
-{
- struct iovec local_iov = { .iov_base = buf, .iov_len = count };
- struct kiocb kiocb;
- ssize_t ret;
-
- init_sync_kiocb(&kiocb, filp);
- ret = __generic_file_aio_read(&kiocb, &local_iov, 1, ppos);
- if (-EIOCBQUEUED == ret)
- ret = wait_on_sync_kiocb(&kiocb);
- return ret;
-}
-EXPORT_SYMBOL(generic_file_read);
-
int file_send_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size)
{
ssize_t written;
return written;
}
+/* FIXME: It would be as simple as this, if we had a (void __user*) to write.
+ * We already have a kernel buffer, so it should be even simpler, right? ;)
+ *
+ * Yes, sorta. After duplicating the complete path of generic_file_write(),
+ * at least some special cases could be removed, so the copy is simpler than
+ * the original. But it remains a copy, so overall complexity increases.
+ */
+static ssize_t
+generic_kernel_file_write(struct file *, const char *, size_t, loff_t *);
+
+ssize_t generic_file_sendpage(struct file *file, struct page *page,
+ int offset, size_t size, loff_t *ppos, int more)
+{
+ ssize_t ret;
+ char *kaddr;
+
+ kaddr = kmap(page);
+ ret = generic_kernel_file_write(file, kaddr + offset, size, ppos);
+ kunmap(page);
+
+ return ret;
+}
+
+EXPORT_SYMBOL(generic_file_sendpage);
+
ssize_t generic_file_sendfile(struct file *in_file, loff_t *ppos,
size_t count, read_actor_t actor, void *target)
{
desc.arg.data = target;
desc.error = 0;
- do_generic_file_read(in_file, ppos, &desc, actor, 0);
+ do_generic_file_read(in_file, ppos, &desc, actor);
if (desc.written)
return desc.written;
return desc.error;
* accessible..
*/
if (area->vm_mm == current->mm)
- return NULL;
+ return NOPAGE_SIGBUS;
/* Fall through to the non-read-ahead case */
no_cached_page:
/*
* effect.
*/
error = page_cache_read(file, pgoff);
- grab_swap_token();
/*
* The page we want has now been added to the page cache.
*/
if (error == -ENOMEM)
return NOPAGE_OOM;
- return NULL;
+ return NOPAGE_SIGBUS;
page_not_uptodate:
if (!did_readaround) {
*/
shrink_readahead_size_eio(file, ra);
page_cache_release(page);
- return NULL;
+ return NOPAGE_SIGBUS;
}
EXPORT_SYMBOL(filemap_nopage);
page_not_uptodate:
lock_page(page);
- /* Did it get unhashed while we waited for it? */
+ /* Did it get truncated while we waited for it? */
if (!page->mapping) {
unlock_page(page);
goto err;
* if suid or (sgid and xgrp)
* remove privs
*/
-int remove_suid(struct dentry *dentry)
+int should_remove_suid(struct dentry *dentry)
{
mode_t mode = dentry->d_inode->i_mode;
int kill = 0;
- int result = 0;
/* suid always must be killed */
if (unlikely(mode & S_ISUID))
if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
kill |= ATTR_KILL_SGID;
- if (unlikely(kill && !capable(CAP_FSETID))) {
- struct iattr newattrs;
+ if (unlikely(kill && !capable(CAP_FSETID)))
+ return kill;
- newattrs.ia_valid = ATTR_FORCE | kill;
- result = notify_change(dentry, &newattrs);
- }
- return result;
+ return 0;
+}
+EXPORT_SYMBOL(should_remove_suid);
+
+int __remove_suid(struct dentry *dentry, int kill)
+{
+ struct iattr newattrs;
+
+ newattrs.ia_valid = ATTR_FORCE | kill;
+ return notify_change(dentry, &newattrs);
+}
+
+int remove_suid(struct dentry *dentry)
+{
+ int kill = should_remove_suid(dentry);
+
+ if (unlikely(kill))
+ return __remove_suid(dentry, kill);
+
+ return 0;
}
EXPORT_SYMBOL(remove_suid);
+static inline size_t
+filemap_copy_from_kernel(struct page *page, unsigned long offset,
+ const char *buf, unsigned bytes)
+{
+ char *kaddr;
+
+ kaddr = kmap(page);
+ memcpy(kaddr + offset, buf, bytes);
+ kunmap(page);
+
+ return bytes;
+}
+
size_t
__filemap_copy_from_user_iovec_inatomic(char *vaddr,
const struct iovec *iov, size_t base, size_t bytes)
if (unlikely(*pos + *count > inode->i_sb->s_maxbytes))
*count = inode->i_sb->s_maxbytes - *pos;
} else {
+#ifdef CONFIG_BLOCK
loff_t isize;
if (bdev_read_only(I_BDEV(inode)))
return -EPERM;
if (*pos + *count > isize)
*count = isize - *pos;
+#else
+ return -EPERM;
+#endif
}
return 0;
}
* Sync the fs metadata but not the minor inode changes and
* of course not the data as we did direct DMA for the IO.
* i_mutex is held, which protects generic_osync_inode() from
- * livelocking.
+ * livelocking. AIO O_DIRECT ops attempt to sync metadata here.
*/
- if (written >= 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
+ if ((written >= 0 || written == -EIOCBQUEUED) &&
+ ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
int err = generic_osync_inode(inode, mapping, OSYNC_METADATA);
if (err < 0)
written = err;
}
- if (written == count && !is_sync_kiocb(iocb))
- written = -EIOCBQUEUED;
return written;
}
EXPORT_SYMBOL(generic_file_direct_write);
}
EXPORT_SYMBOL(generic_file_buffered_write_one_kernel_page);
+static inline void
+filemap_set_next_kvec(const struct kvec **iovp, size_t *basep, size_t bytes)
+{
+ const struct kvec *iov = *iovp;
+ size_t base = *basep;
+
+ while (bytes) {
+ int copy = min(bytes, iov->iov_len - base);
+
+ bytes -= copy;
+ base += copy;
+ if (iov->iov_len == base) {
+ iov++;
+ base = 0;
+ }
+ }
+ *iovp = iov;
+ *basep = base;
+}
+
+/*
+ * TODO:
+ * This largely tries to copy generic_file_aio_write_nolock(), although it
+ * doesn't have to be nearly as generic. A real cleanup should either
+ * merge this into generic_file_aio_write_nolock() as well or keep it special
+ * and remove as much code as possible.
+ */
+static ssize_t
+generic_kernel_file_aio_write_nolock(struct kiocb *iocb, const struct kvec*iov,
+ unsigned long nr_segs, loff_t *ppos)
+{
+ struct file *file = iocb->ki_filp;
+ struct address_space * mapping = file->f_mapping;
+ const struct address_space_operations *a_ops = mapping->a_ops;
+ size_t ocount; /* original count */
+ size_t count; /* after file limit checks */
+ struct inode *inode = mapping->host;
+ long status = 0;
+ loff_t pos;
+ struct page *page;
+ struct page *cached_page = NULL;
+ const int isblk = S_ISBLK(inode->i_mode);
+ ssize_t written;
+ ssize_t err;
+ size_t bytes;
+ struct pagevec lru_pvec;
+ const struct kvec *cur_iov = iov; /* current kvec */
+ size_t iov_base = 0; /* offset in the current kvec */
+ unsigned long seg;
+ char *buf;
+
+ ocount = 0;
+ for (seg = 0; seg < nr_segs; seg++) {
+ const struct kvec *iv = &iov[seg];
+
+ /*
+ * If any segment has a negative length, or the cumulative
+ * length ever wraps negative then return -EINVAL.
+ */
+ ocount += iv->iov_len;
+ if (unlikely((ssize_t)(ocount|iv->iov_len) < 0))
+ return -EINVAL;
+ }
+
+ count = ocount;
+ pos = *ppos;
+ pagevec_init(&lru_pvec, 0);
+
+ /* We can write back this queue in page reclaim */
+ current->backing_dev_info = mapping->backing_dev_info;
+ written = 0;
+
+ err = generic_write_checks(file, &pos, &count, isblk);
+ if (err)
+ goto out;
+
+
+ if (count == 0)
+ goto out;
+
+ remove_suid(file->f_dentry);
+ file_update_time(file);
+
+ /* There is no sane reason to use O_DIRECT */
+ BUG_ON(file->f_flags & O_DIRECT);
+
+ buf = iov->iov_base;
+ do {
+ unsigned long index;
+ unsigned long offset;
+ size_t copied;
+
+ offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
+ index = pos >> PAGE_CACHE_SHIFT;
+ bytes = PAGE_CACHE_SIZE - offset;
+ if (bytes > count)
+ bytes = count;
+
+ page = __grab_cache_page(mapping,index,&cached_page,&lru_pvec);
+ if (!page) {
+ status = -ENOMEM;
+ break;
+ }
+
+ status = a_ops->prepare_write(file, page, offset, offset+bytes);
+ if (unlikely(status)) {
+ loff_t isize = i_size_read(inode);
+ /*
+ * prepare_write() may have instantiated a few blocks
+ * outside i_size. Trim these off again.
+ */
+ unlock_page(page);
+ page_cache_release(page);
+ if (pos + bytes > isize)
+ vmtruncate(inode, isize);
+ break;
+ }
+
+ BUG_ON(nr_segs != 1);
+ copied = filemap_copy_from_kernel(page, offset, buf, bytes);
+
+ flush_dcache_page(page);
+ status = a_ops->commit_write(file, page, offset, offset+bytes);
+ if (likely(copied > 0)) {
+ if (!status)
+ status = copied;
+
+ if (status >= 0) {
+ written += status;
+ count -= status;
+ pos += status;
+ buf += status;
+ if (unlikely(nr_segs > 1))
+ filemap_set_next_kvec(&cur_iov,
+ &iov_base, status);
+ }
+ }
+ if (unlikely(copied != bytes))
+ if (status >= 0)
+ status = -EFAULT;
+ unlock_page(page);
+ mark_page_accessed(page);
+ page_cache_release(page);
+ if (status < 0)
+ break;
+ balance_dirty_pages_ratelimited(mapping);
+ cond_resched();
+ } while (count);
+ *ppos = pos;
+
+ if (cached_page)
+ page_cache_release(cached_page);
+
+ /*
+ * For now, when the user asks for O_SYNC, we'll actually give O_DSYNC
+ */
+ if (status >= 0) {
+ if ((file->f_flags & O_SYNC) || IS_SYNC(inode))
+ status = generic_osync_inode(inode, mapping,
+ OSYNC_METADATA|OSYNC_DATA);
+ }
+
+ err = written ? written : status;
+out:
+ pagevec_lru_add(&lru_pvec);
+ current->backing_dev_info = 0;
+ return err;
+}
+
static ssize_t
__generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t *ppos)
{
struct file *file = iocb->ki_filp;
- const struct address_space * mapping = file->f_mapping;
+ struct address_space * mapping = file->f_mapping;
size_t ocount; /* original count */
size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
if (count == 0)
goto out;
- err = remove_suid(file->f_dentry);
+ err = remove_suid(file->f_path.dentry);
if (err)
goto out;
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (unlikely(file->f_flags & O_DIRECT)) {
- written = generic_file_direct_write(iocb, iov,
- &nr_segs, pos, ppos, count, ocount);
+ loff_t endbyte;
+ ssize_t written_buffered;
+
+ written = generic_file_direct_write(iocb, iov, &nr_segs, pos,
+ ppos, count, ocount);
if (written < 0 || written == count)
goto out;
/*
*/
pos += written;
count -= written;
- }
+ written_buffered = generic_file_buffered_write(iocb, iov,
+ nr_segs, pos, ppos, count,
+ written);
+ /*
+ * If generic_file_buffered_write() retuned a synchronous error
+ * then we want to return the number of bytes which were
+ * direct-written, or the error code if that was zero. Note
+ * that this differs from normal direct-io semantics, which
+ * will return -EFOO even if some bytes were written.
+ */
+ if (written_buffered < 0) {
+ err = written_buffered;
+ goto out;
+ }
- written = generic_file_buffered_write(iocb, iov, nr_segs,
- pos, ppos, count, written);
+ /*
+ * We need to ensure that the page cache pages are written to
+ * disk and invalidated to preserve the expected O_DIRECT
+ * semantics.
+ */
+ endbyte = pos + written_buffered - written - 1;
+ err = do_sync_file_range(file, pos, endbyte,
+ SYNC_FILE_RANGE_WAIT_BEFORE|
+ SYNC_FILE_RANGE_WRITE|
+ SYNC_FILE_RANGE_WAIT_AFTER);
+ if (err == 0) {
+ written = written_buffered;
+ invalidate_mapping_pages(mapping,
+ pos >> PAGE_CACHE_SHIFT,
+ endbyte >> PAGE_CACHE_SHIFT);
+ } else {
+ /*
+ * We don't know how much we wrote, so just return
+ * the number of bytes which were direct-written
+ */
+ }
+ } else {
+ written = generic_file_buffered_write(iocb, iov, nr_segs,
+ pos, ppos, count, written);
+ }
out:
current->backing_dev_info = NULL;
return written ? written : err;
}
-EXPORT_SYMBOL(generic_file_aio_write_nolock);
-
-ssize_t
-generic_file_aio_write_nolock(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t *ppos)
-{
- struct file *file = iocb->ki_filp;
- struct address_space *mapping = file->f_mapping;
- struct inode *inode = mapping->host;
- ssize_t ret;
- loff_t pos = *ppos;
-
- ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs, ppos);
-
- if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
- int err;
-
- err = sync_page_range_nolock(inode, mapping, pos, ret);
- if (err < 0)
- ret = err;
- }
- return ret;
-}
static ssize_t
-__generic_file_write_nolock(struct file *file, const struct iovec *iov,
- unsigned long nr_segs, loff_t *ppos)
+generic_kernel_file_write_nolock(struct file *file, const struct kvec *iov,
+ unsigned long nr_segs, loff_t *ppos)
{
struct kiocb kiocb;
ssize_t ret;
init_sync_kiocb(&kiocb, file);
- ret = __generic_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
+ ret = generic_kernel_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
if (ret == -EIOCBQUEUED)
ret = wait_on_sync_kiocb(&kiocb);
return ret;
}
-ssize_t
-generic_file_write_nolock(struct file *file, const struct iovec *iov,
- unsigned long nr_segs, loff_t *ppos)
+static ssize_t generic_kernel_file_write(struct file *file, const char *buf,
+ size_t count, loff_t *ppos)
{
- struct kiocb kiocb;
- ssize_t ret;
+ struct inode *inode = file->f_mapping->host;
+ ssize_t err;
+ struct kvec local_iov = { .iov_base = (char *) buf,
+ .iov_len = count };
- init_sync_kiocb(&kiocb, file);
- ret = generic_file_aio_write_nolock(&kiocb, iov, nr_segs, ppos);
- if (-EIOCBQUEUED == ret)
- ret = wait_on_sync_kiocb(&kiocb);
- return ret;
+ mutex_lock(&inode->i_mutex);
+ err = generic_kernel_file_write_nolock(file, &local_iov, 1, ppos);
+ mutex_unlock(&inode->i_mutex);
+
+ return err;
}
-EXPORT_SYMBOL(generic_file_write_nolock);
-ssize_t generic_file_aio_write(struct kiocb *iocb, const char __user *buf,
- size_t count, loff_t pos)
+
+ssize_t generic_file_aio_write_nolock(struct kiocb *iocb,
+ const struct iovec *iov, unsigned long nr_segs, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
ssize_t ret;
- struct iovec local_iov = { .iov_base = (void __user *)buf,
- .iov_len = count };
BUG_ON(iocb->ki_pos != pos);
- mutex_lock(&inode->i_mutex);
- ret = __generic_file_aio_write_nolock(iocb, &local_iov, 1,
- &iocb->ki_pos);
- mutex_unlock(&inode->i_mutex);
+ ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs,
+ &iocb->ki_pos);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
ssize_t err;
- err = sync_page_range(inode, mapping, pos, ret);
+ err = sync_page_range_nolock(inode, mapping, pos, ret);
if (err < 0)
ret = err;
}
return ret;
}
-EXPORT_SYMBOL(generic_file_aio_write);
+EXPORT_SYMBOL(generic_file_aio_write_nolock);
-ssize_t generic_file_write(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
+ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
{
+ struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
- ssize_t ret;
- struct iovec local_iov = { .iov_base = (void __user *)buf,
- .iov_len = count };
-
- mutex_lock(&inode->i_mutex);
- ret = __generic_file_write_nolock(file, &local_iov, 1, ppos);
- mutex_unlock(&inode->i_mutex);
-
- if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
- ssize_t err;
-
- err = sync_page_range(inode, mapping, *ppos - ret, ret);
- if (err < 0)
- ret = err;
- }
- return ret;
-}
-EXPORT_SYMBOL(generic_file_write);
-
-ssize_t generic_file_readv(struct file *filp, const struct iovec *iov,
- unsigned long nr_segs, loff_t *ppos)
-{
- struct kiocb kiocb;
ssize_t ret;
- init_sync_kiocb(&kiocb, filp);
- ret = __generic_file_aio_read(&kiocb, iov, nr_segs, ppos);
- if (-EIOCBQUEUED == ret)
- ret = wait_on_sync_kiocb(&kiocb);
- return ret;
-}
-EXPORT_SYMBOL(generic_file_readv);
-
-ssize_t generic_file_writev(struct file *file, const struct iovec *iov,
- unsigned long nr_segs, loff_t *ppos)
-{
- struct address_space *mapping = file->f_mapping;
- struct inode *inode = mapping->host;
- ssize_t ret;
+ BUG_ON(iocb->ki_pos != pos);
mutex_lock(&inode->i_mutex);
- ret = __generic_file_write_nolock(file, iov, nr_segs, ppos);
+ ret = __generic_file_aio_write_nolock(iocb, iov, nr_segs,
+ &iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
if (ret > 0 && ((file->f_flags & O_SYNC) || IS_SYNC(inode))) {
- int err;
+ ssize_t err;
- err = sync_page_range(inode, mapping, *ppos - ret, ret);
+ err = sync_page_range(inode, mapping, pos, ret);
if (err < 0)
ret = err;
}
return ret;
}
-EXPORT_SYMBOL(generic_file_writev);
+EXPORT_SYMBOL(generic_file_aio_write);
/*
* Called under i_mutex for writes to S_ISREG files. Returns -EIO if something
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
ssize_t retval;
- size_t write_len = 0;
+ size_t write_len;
+ pgoff_t end = 0; /* silence gcc */
/*
* If it's a write, unmap all mmappings of the file up-front. This
*/
if (rw == WRITE) {
write_len = iov_length(iov, nr_segs);
+ end = (offset + write_len - 1) >> PAGE_CACHE_SHIFT;
if (mapping_mapped(mapping))
unmap_mapping_range(mapping, offset, write_len, 0);
}
retval = filemap_write_and_wait(mapping);
- if (retval == 0) {
- retval = mapping->a_ops->direct_IO(rw, iocb, iov,
- offset, nr_segs);
- if (rw == WRITE && mapping->nrpages) {
- pgoff_t end = (offset + write_len - 1)
- >> PAGE_CACHE_SHIFT;
- int err = invalidate_inode_pages2_range(mapping,
+ if (retval)
+ goto out;
+
+ /*
+ * After a write we want buffered reads to be sure to go to disk to get
+ * the new data. We invalidate clean cached page from the region we're
+ * about to write. We do this *before* the write so that we can return
+ * -EIO without clobbering -EIOCBQUEUED from ->direct_IO().
+ */
+ if (rw == WRITE && mapping->nrpages) {
+ retval = invalidate_inode_pages2_range(mapping,
offset >> PAGE_CACHE_SHIFT, end);
- if (err)
- retval = err;
- }
+ if (retval)
+ goto out;
+ }
+
+ retval = mapping->a_ops->direct_IO(rw, iocb, iov, offset, nr_segs);
+ if (retval)
+ goto out;
+
+ /*
+ * Finally, try again to invalidate clean pages which might have been
+ * faulted in by get_user_pages() if the source of the write was an
+ * mmap()ed region of the file we're writing. That's a pretty crazy
+ * thing to do, so we don't support it 100%. If this invalidation
+ * fails and we have -EIOCBQUEUED we ignore the failure.
+ */
+ if (rw == WRITE && mapping->nrpages) {
+ int err = invalidate_inode_pages2_range(mapping,
+ offset >> PAGE_CACHE_SHIFT, end);
+ if (err && retval >= 0)
+ retval = err;
}
+out:
return retval;
}
+
+/**
+ * try_to_release_page() - release old fs-specific metadata on a page
+ *
+ * @page: the page which the kernel is trying to free
+ * @gfp_mask: memory allocation flags (and I/O mode)
+ *
+ * The address_space is to try to release any data against the page
+ * (presumably at page->private). If the release was successful, return `1'.
+ * Otherwise return zero.
+ *
+ * The @gfp_mask argument specifies whether I/O may be performed to release
+ * this page (__GFP_IO), and whether the call may block (__GFP_WAIT).
+ *
+ * NOTE: @gfp_mask may go away, and this function may become non-blocking.
+ */
+int try_to_release_page(struct page *page, gfp_t gfp_mask)
+{
+ struct address_space * const mapping = page->mapping;
+
+ BUG_ON(!PageLocked(page));
+ if (PageWriteback(page))
+ return 0;
+
+ if (mapping && mapping->a_ops->releasepage)
+ return mapping->a_ops->releasepage(page, gfp_mask);
+ return try_to_free_buffers(page);
+}
+
+EXPORT_SYMBOL(try_to_release_page);
git://git.onelab.eu / linux-2.6.git / blobdiff