file.c 24.4 KB
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#include <linux/ceph/ceph_debug.h>
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#include <linux/module.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/file.h>
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#include <linux/mount.h>
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#include <linux/namei.h>
#include <linux/writeback.h>

#include "super.h"
#include "mds_client.h"

/*
 * Ceph file operations
 *
 * Implement basic open/close functionality, and implement
 * read/write.
 *
 * We implement three modes of file I/O:
 *  - buffered uses the generic_file_aio_{read,write} helpers
 *
 *  - synchronous is used when there is multi-client read/write
 *    sharing, avoids the page cache, and synchronously waits for an
 *    ack from the OSD.
 *
 *  - direct io takes the variant of the sync path that references
 *    user pages directly.
 *
 * fsync() flushes and waits on dirty pages, but just queues metadata
 * for writeback: since the MDS can recover size and mtime there is no
 * need to wait for MDS acknowledgement.
 */


/*
 * Prepare an open request.  Preallocate ceph_cap to avoid an
 * inopportune ENOMEM later.
 */
static struct ceph_mds_request *
prepare_open_request(struct super_block *sb, int flags, int create_mode)
{
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	struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
	struct ceph_mds_client *mdsc = fsc->mdsc;
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	struct ceph_mds_request *req;
	int want_auth = USE_ANY_MDS;
	int op = (flags & O_CREAT) ? CEPH_MDS_OP_CREATE : CEPH_MDS_OP_OPEN;

	if (flags & (O_WRONLY|O_RDWR|O_CREAT|O_TRUNC))
		want_auth = USE_AUTH_MDS;

	req = ceph_mdsc_create_request(mdsc, op, want_auth);
	if (IS_ERR(req))
		goto out;
	req->r_fmode = ceph_flags_to_mode(flags);
	req->r_args.open.flags = cpu_to_le32(flags);
	req->r_args.open.mode = cpu_to_le32(create_mode);
out:
	return req;
}

/*
 * initialize private struct file data.
 * if we fail, clean up by dropping fmode reference on the ceph_inode
 */
static int ceph_init_file(struct inode *inode, struct file *file, int fmode)
{
	struct ceph_file_info *cf;
	int ret = 0;

	switch (inode->i_mode & S_IFMT) {
	case S_IFREG:
	case S_IFDIR:
		dout("init_file %p %p 0%o (regular)\n", inode, file,
		     inode->i_mode);
		cf = kmem_cache_alloc(ceph_file_cachep, GFP_NOFS | __GFP_ZERO);
		if (cf == NULL) {
			ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
			return -ENOMEM;
		}
		cf->fmode = fmode;
		cf->next_offset = 2;
		file->private_data = cf;
		BUG_ON(inode->i_fop->release != ceph_release);
		break;

	case S_IFLNK:
		dout("init_file %p %p 0%o (symlink)\n", inode, file,
		     inode->i_mode);
		ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
		break;

	default:
		dout("init_file %p %p 0%o (special)\n", inode, file,
		     inode->i_mode);
		/*
		 * we need to drop the open ref now, since we don't
		 * have .release set to ceph_release.
		 */
		ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
		BUG_ON(inode->i_fop->release == ceph_release);

		/* call the proper open fop */
		ret = inode->i_fop->open(inode, file);
	}
	return ret;
}

/*
 * If we already have the requisite capabilities, we can satisfy
 * the open request locally (no need to request new caps from the
 * MDS).  We do, however, need to inform the MDS (asynchronously)
 * if our wanted caps set expands.
 */
int ceph_open(struct inode *inode, struct file *file)
{
	struct ceph_inode_info *ci = ceph_inode(inode);
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	struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
	struct ceph_mds_client *mdsc = fsc->mdsc;
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	struct ceph_mds_request *req;
	struct ceph_file_info *cf = file->private_data;
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	struct inode *parent_inode = NULL;
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	int err;
	int flags, fmode, wanted;

	if (cf) {
		dout("open file %p is already opened\n", file);
		return 0;
	}

	/* filter out O_CREAT|O_EXCL; vfs did that already.  yuck. */
	flags = file->f_flags & ~(O_CREAT|O_EXCL);
	if (S_ISDIR(inode->i_mode))
		flags = O_DIRECTORY;  /* mds likes to know */

	dout("open inode %p ino %llx.%llx file %p flags %d (%d)\n", inode,
	     ceph_vinop(inode), file, flags, file->f_flags);
	fmode = ceph_flags_to_mode(flags);
	wanted = ceph_caps_for_mode(fmode);

	/* snapped files are read-only */
	if (ceph_snap(inode) != CEPH_NOSNAP && (file->f_mode & FMODE_WRITE))
		return -EROFS;

	/* trivially open snapdir */
	if (ceph_snap(inode) == CEPH_SNAPDIR) {
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		spin_lock(&ci->i_ceph_lock);
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		__ceph_get_fmode(ci, fmode);
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		spin_unlock(&ci->i_ceph_lock);
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		return ceph_init_file(inode, file, fmode);
	}

	/*
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	 * No need to block if we have caps on the auth MDS (for
	 * write) or any MDS (for read).  Update wanted set
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	 * asynchronously.
	 */
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	spin_lock(&ci->i_ceph_lock);
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	if (__ceph_is_any_real_caps(ci) &&
	    (((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap)) {
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		int mds_wanted = __ceph_caps_mds_wanted(ci);
		int issued = __ceph_caps_issued(ci, NULL);

		dout("open %p fmode %d want %s issued %s using existing\n",
		     inode, fmode, ceph_cap_string(wanted),
		     ceph_cap_string(issued));
		__ceph_get_fmode(ci, fmode);
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		spin_unlock(&ci->i_ceph_lock);
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		/* adjust wanted? */
		if ((issued & wanted) != wanted &&
		    (mds_wanted & wanted) != wanted &&
		    ceph_snap(inode) != CEPH_SNAPDIR)
			ceph_check_caps(ci, 0, NULL);

		return ceph_init_file(inode, file, fmode);
	} else if (ceph_snap(inode) != CEPH_NOSNAP &&
		   (ci->i_snap_caps & wanted) == wanted) {
		__ceph_get_fmode(ci, fmode);
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		spin_unlock(&ci->i_ceph_lock);
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		return ceph_init_file(inode, file, fmode);
	}
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	spin_unlock(&ci->i_ceph_lock);
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	dout("open fmode %d wants %s\n", fmode, ceph_cap_string(wanted));
	req = prepare_open_request(inode->i_sb, flags, 0);
	if (IS_ERR(req)) {
		err = PTR_ERR(req);
		goto out;
	}
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	req->r_inode = inode;
	ihold(inode);
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	req->r_num_caps = 1;
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	if (flags & (O_CREAT|O_TRUNC))
		parent_inode = ceph_get_dentry_parent_inode(file->f_dentry);
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	err = ceph_mdsc_do_request(mdsc, parent_inode, req);
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	iput(parent_inode);
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	if (!err)
		err = ceph_init_file(inode, file, req->r_fmode);
	ceph_mdsc_put_request(req);
	dout("open result=%d on %llx.%llx\n", err, ceph_vinop(inode));
out:
	return err;
}


/*
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 * Do a lookup + open with a single request.  If we get a non-existent
 * file or symlink, return 1 so the VFS can retry.
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 */
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int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
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		     struct file *file, unsigned flags, umode_t mode,
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		     int *opened)
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{
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	struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
	struct ceph_mds_client *mdsc = fsc->mdsc;
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	struct ceph_mds_request *req;
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	struct dentry *dn;
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	int err;

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	dout("atomic_open %p dentry %p '%.*s' %s flags %d mode 0%o\n",
	     dir, dentry, dentry->d_name.len, dentry->d_name.name,
	     d_unhashed(dentry) ? "unhashed" : "hashed", flags, mode);

	if (dentry->d_name.len > NAME_MAX)
		return -ENAMETOOLONG;

	err = ceph_init_dentry(dentry);
	if (err < 0)
		return err;
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	/* do the open */
	req = prepare_open_request(dir->i_sb, flags, mode);
	if (IS_ERR(req))
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		return PTR_ERR(req);
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	req->r_dentry = dget(dentry);
	req->r_num_caps = 2;
	if (flags & O_CREAT) {
		req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
		req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
	}
	req->r_locked_dir = dir;           /* caller holds dir->i_mutex */
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	err = ceph_mdsc_do_request(mdsc,
				   (flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
				   req);
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	if (err)
		goto out_err;

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	err = ceph_handle_snapdir(req, dentry, err);
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	if (err == 0 && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
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		err = ceph_handle_notrace_create(dir, dentry);
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	if (d_unhashed(dentry)) {
		dn = ceph_finish_lookup(req, dentry, err);
		if (IS_ERR(dn))
			err = PTR_ERR(dn);
	} else {
		/* we were given a hashed negative dentry */
		dn = NULL;
	}
	if (err)
		goto out_err;
	if (dn || dentry->d_inode == NULL || S_ISLNK(dentry->d_inode->i_mode)) {
		/* make vfs retry on splice, ENOENT, or symlink */
		dout("atomic_open finish_no_open on dn %p\n", dn);
		err = finish_no_open(file, dn);
	} else {
		dout("atomic_open finish_open on dn %p\n", dn);
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		if (req->r_op == CEPH_MDS_OP_CREATE && req->r_reply_info.has_create_ino) {
			*opened |= FILE_CREATED;
		}
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		err = finish_open(file, dentry, ceph_open, opened);
	}
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out_err:
	ceph_mdsc_put_request(req);
	dout("atomic_open result=%d\n", err);
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	return err;
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}

int ceph_release(struct inode *inode, struct file *file)
{
	struct ceph_inode_info *ci = ceph_inode(inode);
	struct ceph_file_info *cf = file->private_data;

	dout("release inode %p file %p\n", inode, file);
	ceph_put_fmode(ci, cf->fmode);
	if (cf->last_readdir)
		ceph_mdsc_put_request(cf->last_readdir);
	kfree(cf->last_name);
	kfree(cf->dir_info);
	dput(cf->dentry);
	kmem_cache_free(ceph_file_cachep, cf);
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	/* wake up anyone waiting for caps on this inode */
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	wake_up_all(&ci->i_cap_wq);
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	return 0;
}

/*
 * Read a range of bytes striped over one or more objects.  Iterate over
 * objects we stripe over.  (That's not atomic, but good enough for now.)
 *
 * If we get a short result from the OSD, check against i_size; we need to
 * only return a short read to the caller if we hit EOF.
 */
static int striped_read(struct inode *inode,
			u64 off, u64 len,
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			struct page **pages, int num_pages,
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			int *checkeof, bool o_direct,
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			unsigned long buf_align)
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{
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	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
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	struct ceph_inode_info *ci = ceph_inode(inode);
	u64 pos, this_len;
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	int io_align, page_align;
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	int left, pages_left;
	int read;
	struct page **page_pos;
	int ret;
	bool hit_stripe, was_short;

	/*
	 * we may need to do multiple reads.  not atomic, unfortunately.
	 */
	pos = off;
	left = len;
	page_pos = pages;
	pages_left = num_pages;
	read = 0;
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	io_align = off & ~PAGE_MASK;
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more:
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	if (o_direct)
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		page_align = (pos - io_align + buf_align) & ~PAGE_MASK;
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	else
		page_align = pos & ~PAGE_MASK;
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	this_len = left;
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	ret = ceph_osdc_readpages(&fsc->client->osdc, ceph_vino(inode),
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				  &ci->i_layout, pos, &this_len,
				  ci->i_truncate_seq,
				  ci->i_truncate_size,
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				  page_pos, pages_left, page_align);
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	if (ret == -ENOENT)
		ret = 0;
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	hit_stripe = this_len < left;
	was_short = ret >= 0 && ret < this_len;
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	dout("striped_read %llu~%u (read %u) got %d%s%s\n", pos, left, read,
	     ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");

	if (ret > 0) {
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		int didpages = (page_align + ret) >> PAGE_CACHE_SHIFT;
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		if (read < pos - off) {
			dout(" zero gap %llu to %llu\n", off + read, pos);
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			ceph_zero_page_vector_range(page_align + read,
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						    pos - off - read, pages);
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		}
		pos += ret;
		read = pos - off;
		left -= ret;
		page_pos += didpages;
		pages_left -= didpages;

		/* hit stripe? */
		if (left && hit_stripe)
			goto more;
	}

	if (was_short) {
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		/* did we bounce off eof? */
		if (pos + left > inode->i_size)
			*checkeof = 1;

		/* zero trailing bytes (inside i_size) */
		if (left > 0 && pos < inode->i_size) {
			if (pos + left > inode->i_size)
				left = inode->i_size - pos;

			dout("zero tail %d\n", left);
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			ceph_zero_page_vector_range(page_align + read, left,
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						    pages);
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			read += left;
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		}
	}

	if (ret >= 0)
		ret = read;
	dout("striped_read returns %d\n", ret);
	return ret;
}

/*
 * Completely synchronous read and write methods.  Direct from __user
 * buffer to osd, or directly to user pages (if O_DIRECT).
 *
 * If the read spans object boundary, just do multiple reads.
 */
static ssize_t ceph_sync_read(struct file *file, char __user *data,
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			      unsigned len, loff_t *poff, int *checkeof)
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{
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	struct inode *inode = file_inode(file);
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	struct page **pages;
	u64 off = *poff;
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	int num_pages, ret;
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	dout("sync_read on file %p %llu~%u %s\n", file, off, len,
	     (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");

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	if (file->f_flags & O_DIRECT) {
		num_pages = calc_pages_for((unsigned long)data, len);
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		pages = ceph_get_direct_page_vector(data, num_pages, true);
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	} else {
		num_pages = calc_pages_for(off, len);
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		pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
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	}
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	if (IS_ERR(pages))
		return PTR_ERR(pages);

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	/*
	 * flush any page cache pages in this range.  this
	 * will make concurrent normal and sync io slow,
	 * but it will at least behave sensibly when they are
	 * in sequence.
	 */
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	ret = filemap_write_and_wait(inode->i_mapping);
	if (ret < 0)
		goto done;

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	ret = striped_read(inode, off, len, pages, num_pages, checkeof,
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			   file->f_flags & O_DIRECT,
			   (unsigned long)data & ~PAGE_MASK);
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	if (ret >= 0 && (file->f_flags & O_DIRECT) == 0)
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		ret = ceph_copy_page_vector_to_user(pages, data, off, ret);
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	if (ret >= 0)
		*poff = off + ret;

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done:
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	if (file->f_flags & O_DIRECT)
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		ceph_put_page_vector(pages, num_pages, true);
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	else
		ceph_release_page_vector(pages, num_pages);
	dout("sync_read result %d\n", ret);
	return ret;
}

/*
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 * Write commit request unsafe callback, called to tell us when a
 * request is unsafe (that is, in flight--has been handed to the
 * messenger to send to its target osd).  It is called again when
 * we've received a response message indicating the request is
 * "safe" (its CEPH_OSD_FLAG_ONDISK flag is set), or when a request
 * is completed early (and unsuccessfully) due to a timeout or
 * interrupt.
 *
 * This is used if we requested both an ACK and ONDISK commit reply
 * from the OSD.
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 */
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static void ceph_sync_write_unsafe(struct ceph_osd_request *req, bool unsafe)
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{
	struct ceph_inode_info *ci = ceph_inode(req->r_inode);

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	dout("%s %p tid %llu %ssafe\n", __func__, req, req->r_tid,
		unsafe ? "un" : "");
	if (unsafe) {
		ceph_get_cap_refs(ci, CEPH_CAP_FILE_WR);
		spin_lock(&ci->i_unsafe_lock);
		list_add_tail(&req->r_unsafe_item,
			      &ci->i_unsafe_writes);
		spin_unlock(&ci->i_unsafe_lock);
	} else {
		spin_lock(&ci->i_unsafe_lock);
		list_del_init(&req->r_unsafe_item);
		spin_unlock(&ci->i_unsafe_lock);
		ceph_put_cap_refs(ci, CEPH_CAP_FILE_WR);
	}
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}

/*
 * Synchronous write, straight from __user pointer or user pages (if
 * O_DIRECT).
 *
 * If write spans object boundary, just do multiple writes.  (For a
 * correct atomic write, we should e.g. take write locks on all
 * objects, rollback on failure, etc.)
 */
static ssize_t ceph_sync_write(struct file *file, const char __user *data,
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			       size_t left, loff_t pos, loff_t *ppos)
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{
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	struct inode *inode = file_inode(file);
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	struct ceph_inode_info *ci = ceph_inode(inode);
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	struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
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	struct ceph_snap_context *snapc;
	struct ceph_vino vino;
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	struct ceph_osd_request *req;
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	int num_ops = 1;
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	struct page **pages;
	int num_pages;
	u64 len;
	int written = 0;
	int flags;
	int check_caps = 0;
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	int page_align, io_align;
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	unsigned long buf_align;
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	int ret;
	struct timespec mtime = CURRENT_TIME;
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	bool own_pages = false;
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	if (ceph_snap(file_inode(file)) != CEPH_NOSNAP)
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		return -EROFS;

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	dout("sync_write on file %p %lld~%u %s\n", file, pos,
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	     (unsigned)left, (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");

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	ret = filemap_write_and_wait_range(inode->i_mapping, pos, pos + left);
	if (ret < 0)
		return ret;

	ret = invalidate_inode_pages2_range(inode->i_mapping,
					    pos >> PAGE_CACHE_SHIFT,
					    (pos + left) >> PAGE_CACHE_SHIFT);
	if (ret < 0)
		dout("invalidate_inode_pages2_range returned %d\n", ret);

S
Sage Weil 已提交
526 527 528 529 530 531
	flags = CEPH_OSD_FLAG_ORDERSNAP |
		CEPH_OSD_FLAG_ONDISK |
		CEPH_OSD_FLAG_WRITE;
	if ((file->f_flags & (O_SYNC|O_DIRECT)) == 0)
		flags |= CEPH_OSD_FLAG_ACK;
	else
532
		num_ops++;	/* Also include a 'startsync' command. */
S
Sage Weil 已提交
533 534 535 536 537 538

	/*
	 * we may need to do multiple writes here if we span an object
	 * boundary.  this isn't atomic, unfortunately.  :(
	 */
more:
539 540
	io_align = pos & ~PAGE_MASK;
	buf_align = (unsigned long)data & ~PAGE_MASK;
S
Sage Weil 已提交
541
	len = left;
542

543 544
	snapc = ci->i_snap_realm->cached_context;
	vino = ceph_vino(inode);
545
	req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
546
				    vino, pos, &len, num_ops,
547
				    CEPH_OSD_OP_WRITE, flags, snapc,
S
Sage Weil 已提交
548
				    ci->i_truncate_seq, ci->i_truncate_size,
549
				    false);
550 551
	if (IS_ERR(req))
		return PTR_ERR(req);
S
Sage Weil 已提交
552

553 554 555
	/* write from beginning of first page, regardless of io alignment */
	page_align = file->f_flags & O_DIRECT ? buf_align : io_align;
	num_pages = calc_pages_for(page_align, len);
S
Sage Weil 已提交
556
	if (file->f_flags & O_DIRECT) {
557
		pages = ceph_get_direct_page_vector(data, num_pages, false);
S
Sage Weil 已提交
558 559 560 561 562 563 564 565 566
		if (IS_ERR(pages)) {
			ret = PTR_ERR(pages);
			goto out;
		}

		/*
		 * throw out any page cache pages in this range. this
		 * may block.
		 */
S
Sage Weil 已提交
567
		truncate_inode_pages_range(inode->i_mapping, pos,
S
Sage Weil 已提交
568
					   (pos+len) | (PAGE_CACHE_SIZE-1));
S
Sage Weil 已提交
569
	} else {
570
		pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
S
Sage Weil 已提交
571 572 573 574
		if (IS_ERR(pages)) {
			ret = PTR_ERR(pages);
			goto out;
		}
575
		ret = ceph_copy_user_to_page_vector(pages, data, pos, len);
S
Sage Weil 已提交
576 577 578 579 580 581 582
		if (ret < 0) {
			ceph_release_page_vector(pages, num_pages);
			goto out;
		}

		if ((file->f_flags & O_SYNC) == 0) {
			/* get a second commit callback */
583 584
			req->r_unsafe_callback = ceph_sync_write_unsafe;
			req->r_inode = inode;
585
			own_pages = true;
S
Sage Weil 已提交
586 587
		}
	}
588
	osd_req_op_extent_osd_data_pages(req, 0, true, pages, len,
589
					page_align, false, own_pages);
S
Sage Weil 已提交
590

591
	/* BUG_ON(vino.snap != CEPH_NOSNAP); */
592
	ceph_osdc_build_request(req, pos, snapc, vino.snap, &mtime);
593

594
	ret = ceph_osdc_start_request(&fsc->client->osdc, req, false);
595
	if (!ret)
596
		ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
S
Sage Weil 已提交
597 598

	if (file->f_flags & O_DIRECT)
599
		ceph_put_page_vector(pages, num_pages, false);
S
Sage Weil 已提交
600 601 602 603 604 605 606 607 608
	else if (file->f_flags & O_SYNC)
		ceph_release_page_vector(pages, num_pages);

out:
	ceph_osdc_put_request(req);
	if (ret == 0) {
		pos += len;
		written += len;
		left -= len;
609
		data += len;
S
Sage Weil 已提交
610 611 612 613
		if (left)
			goto more;

		ret = written;
614
		*ppos = pos;
S
Sage Weil 已提交
615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634
		if (pos > i_size_read(inode))
			check_caps = ceph_inode_set_size(inode, pos);
		if (check_caps)
			ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY,
					NULL);
	}
	return ret;
}

/*
 * Wrap generic_file_aio_read with checks for cap bits on the inode.
 * Atomically grab references, so that those bits are not released
 * back to the MDS mid-read.
 *
 * Hmm, the sync read case isn't actually async... should it be?
 */
static ssize_t ceph_aio_read(struct kiocb *iocb, const struct iovec *iov,
			     unsigned long nr_segs, loff_t pos)
{
	struct file *filp = iocb->ki_filp;
635
	struct ceph_file_info *fi = filp->private_data;
S
Sage Weil 已提交
636 637
	loff_t *ppos = &iocb->ki_pos;
	size_t len = iov->iov_len;
A
Al Viro 已提交
638
	struct inode *inode = file_inode(filp);
S
Sage Weil 已提交
639
	struct ceph_inode_info *ci = ceph_inode(inode);
Y
Yehuda Sadeh 已提交
640
	void __user *base = iov->iov_base;
S
Sage Weil 已提交
641
	ssize_t ret;
642
	int want, got = 0;
643
	int checkeof = 0, read = 0;
S
Sage Weil 已提交
644 645 646

	dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
	     inode, ceph_vinop(inode), pos, (unsigned)len, inode);
647
again:
648 649 650 651 652
	if (fi->fmode & CEPH_FILE_MODE_LAZY)
		want = CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO;
	else
		want = CEPH_CAP_FILE_CACHE;
	ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, want, &got, -1);
S
Sage Weil 已提交
653 654 655 656 657 658
	if (ret < 0)
		goto out;
	dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
	     inode, ceph_vinop(inode), pos, (unsigned)len,
	     ceph_cap_string(got));

659
	if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||
S
Sage Weil 已提交
660
	    (iocb->ki_filp->f_flags & O_DIRECT) ||
661 662
	    (inode->i_sb->s_flags & MS_SYNCHRONOUS) ||
	    (fi->flags & CEPH_F_SYNC))
S
Sage Weil 已提交
663
		/* hmm, this isn't really async... */
664
		ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
S
Sage Weil 已提交
665 666 667 668 669 670 671
	else
		ret = generic_file_aio_read(iocb, iov, nr_segs, pos);

out:
	dout("aio_read %p %llx.%llx dropping cap refs on %s = %d\n",
	     inode, ceph_vinop(inode), ceph_cap_string(got), (int)ret);
	ceph_put_cap_refs(ci, got);
672 673 674 675 676 677

	if (checkeof && ret >= 0) {
		int statret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);

		/* hit EOF or hole? */
		if (statret == 0 && *ppos < inode->i_size) {
678
			dout("aio_read sync_read hit hole, ppos %lld < size %lld, reading more\n", *ppos, inode->i_size);
679 680 681 682 683 684 685 686 687 688
			read += ret;
			base += ret;
			len -= ret;
			checkeof = 0;
			goto again;
		}
	}
	if (ret >= 0)
		ret += read;

S
Sage Weil 已提交
689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705
	return ret;
}

/*
 * Take cap references to avoid releasing caps to MDS mid-write.
 *
 * If we are synchronous, and write with an old snap context, the OSD
 * may return EOLDSNAPC.  In that case, retry the write.. _after_
 * dropping our cap refs and allowing the pending snap to logically
 * complete _before_ this write occurs.
 *
 * If we are near ENOSPC, write synchronously.
 */
static ssize_t ceph_aio_write(struct kiocb *iocb, const struct iovec *iov,
		       unsigned long nr_segs, loff_t pos)
{
	struct file *file = iocb->ki_filp;
706
	struct ceph_file_info *fi = file->private_data;
A
Al Viro 已提交
707
	struct inode *inode = file_inode(file);
S
Sage Weil 已提交
708
	struct ceph_inode_info *ci = ceph_inode(inode);
709 710
	struct ceph_osd_client *osdc =
		&ceph_sb_to_client(inode->i_sb)->client->osdc;
711 712 713
	ssize_t count, written = 0;
	int err, want, got;
	bool hold_mutex;
S
Sage Weil 已提交
714 715 716 717

	if (ceph_snap(inode) != CEPH_NOSNAP)
		return -EROFS;

Y
Yan, Zheng 已提交
718
	sb_start_write(inode->i_sb);
719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743
	mutex_lock(&inode->i_mutex);
	hold_mutex = true;

	err = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
	if (err)
		goto out;

	/* We can write back this queue in page reclaim */
	current->backing_dev_info = file->f_mapping->backing_dev_info;

	err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
	if (err)
		goto out;

	if (count == 0)
		goto out;

	err = file_remove_suid(file);
	if (err)
		goto out;

	err = file_update_time(file);
	if (err)
		goto out;

S
Sage Weil 已提交
744
retry_snap:
Y
Yan, Zheng 已提交
745
	if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL)) {
746
		err = -ENOSPC;
Y
Yan, Zheng 已提交
747 748
		goto out;
	}
749

750
	dout("aio_write %p %llx.%llx %llu~%zd getting caps. i_size %llu\n",
751
	     inode, ceph_vinop(inode), pos, count, inode->i_size);
S
Sage Weil 已提交
752 753 754 755
	if (fi->fmode & CEPH_FILE_MODE_LAZY)
		want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
	else
		want = CEPH_CAP_FILE_BUFFER;
756 757 758
	got = 0;
	err = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, &got, pos + count);
	if (err < 0)
759
		goto out;
S
Sage Weil 已提交
760

761
	dout("aio_write %p %llx.%llx %llu~%zd got cap refs on %s\n",
762
	     inode, ceph_vinop(inode), pos, count, ceph_cap_string(got));
S
Sage Weil 已提交
763 764 765 766 767

	if ((got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO)) == 0 ||
	    (iocb->ki_filp->f_flags & O_DIRECT) ||
	    (inode->i_sb->s_flags & MS_SYNCHRONOUS) ||
	    (fi->flags & CEPH_F_SYNC)) {
768
		mutex_unlock(&inode->i_mutex);
769 770
		written = ceph_sync_write(file, iov->iov_base, count,
					  pos, &iocb->ki_pos);
S
Sage Weil 已提交
771
	} else {
772 773 774
		written = generic_file_buffered_write(iocb, iov, nr_segs,
						      pos, &iocb->ki_pos,
						      count, 0);
Y
Yan, Zheng 已提交
775
		mutex_unlock(&inode->i_mutex);
S
Sage Weil 已提交
776
	}
777
	hold_mutex = false;
778

779
	if (written >= 0) {
780
		int dirty;
781
		spin_lock(&ci->i_ceph_lock);
782
		dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
783
		spin_unlock(&ci->i_ceph_lock);
784 785
		if (dirty)
			__mark_inode_dirty(inode, dirty);
S
Sage Weil 已提交
786
	}
S
Sage Weil 已提交
787

S
Sage Weil 已提交
788
	dout("aio_write %p %llx.%llx %llu~%u  dropping cap refs on %s\n",
S
Sage Weil 已提交
789 790
	     inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
	     ceph_cap_string(got));
S
Sage Weil 已提交
791
	ceph_put_cap_refs(ci, got);
S
Sage Weil 已提交
792

793
	if (written >= 0 &&
Y
Yan, Zheng 已提交
794 795
	    ((file->f_flags & O_SYNC) || IS_SYNC(file->f_mapping->host) ||
	     ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_NEARFULL))) {
796
		err = vfs_fsync_range(file, pos, pos + written - 1, 1);
Y
Yan, Zheng 已提交
797
		if (err < 0)
798
			written = err;
Y
Yan, Zheng 已提交
799
	}
800 801

	if (written == -EOLDSNAPC) {
S
Sage Weil 已提交
802 803
		dout("aio_write %p %llx.%llx %llu~%u got EOLDSNAPC, retrying\n",
		     inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len);
804 805
		mutex_lock(&inode->i_mutex);
		hold_mutex = true;
S
Sage Weil 已提交
806 807
		goto retry_snap;
	}
808 809 810
out:
	if (hold_mutex)
		mutex_unlock(&inode->i_mutex);
Y
Yan, Zheng 已提交
811
	sb_end_write(inode->i_sb);
812
	current->backing_dev_info = NULL;
S
Sage Weil 已提交
813

814
	return written ? written : err;
S
Sage Weil 已提交
815 816 817 818 819
}

/*
 * llseek.  be sure to verify file size on SEEK_END.
 */
820
static loff_t ceph_llseek(struct file *file, loff_t offset, int whence)
S
Sage Weil 已提交
821 822 823 824 825
{
	struct inode *inode = file->f_mapping->host;
	int ret;

	mutex_lock(&inode->i_mutex);
826
	__ceph_do_pending_vmtruncate(inode, false);
827

828
	if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
S
Sage Weil 已提交
829 830 831 832 833
		ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
		if (ret < 0) {
			offset = ret;
			goto out;
		}
834 835
	}

836
	switch (whence) {
837
	case SEEK_END:
S
Sage Weil 已提交
838 839 840 841 842 843 844 845 846 847 848 849 850 851 852
		offset += inode->i_size;
		break;
	case SEEK_CUR:
		/*
		 * Here we special-case the lseek(fd, 0, SEEK_CUR)
		 * position-querying operation.  Avoid rewriting the "same"
		 * f_pos value back to the file because a concurrent read(),
		 * write() or lseek() might have altered it
		 */
		if (offset == 0) {
			offset = file->f_pos;
			goto out;
		}
		offset += file->f_pos;
		break;
853 854 855 856 857 858 859 860 861 862 863 864 865
	case SEEK_DATA:
		if (offset >= inode->i_size) {
			ret = -ENXIO;
			goto out;
		}
		break;
	case SEEK_HOLE:
		if (offset >= inode->i_size) {
			ret = -ENXIO;
			goto out;
		}
		offset = inode->i_size;
		break;
S
Sage Weil 已提交
866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893
	}

	if (offset < 0 || offset > inode->i_sb->s_maxbytes) {
		offset = -EINVAL;
		goto out;
	}

	/* Special lock needed here? */
	if (offset != file->f_pos) {
		file->f_pos = offset;
		file->f_version = 0;
	}

out:
	mutex_unlock(&inode->i_mutex);
	return offset;
}

const struct file_operations ceph_file_fops = {
	.open = ceph_open,
	.release = ceph_release,
	.llseek = ceph_llseek,
	.read = do_sync_read,
	.write = do_sync_write,
	.aio_read = ceph_aio_read,
	.aio_write = ceph_aio_write,
	.mmap = ceph_mmap,
	.fsync = ceph_fsync,
G
Greg Farnum 已提交
894 895
	.lock = ceph_lock,
	.flock = ceph_flock,
S
Sage Weil 已提交
896 897 898 899 900 901
	.splice_read = generic_file_splice_read,
	.splice_write = generic_file_splice_write,
	.unlocked_ioctl = ceph_ioctl,
	.compat_ioctl	= ceph_ioctl,
};