ceph: file operations
File open and close operations, and read and write methods that ensure
we have obtained the proper capabilities from the MDS cluster before
performing IO on a file. We take references on held capabilities for
the duration of the read/write to avoid prematurely releasing them
back to the MDS.
We implement two main paths for read and write: one that is buffered
(and uses generic_aio_{read,write}), and one that is fully synchronous
and blocking (operating either on a __user pointer or, if O_DIRECT,
directly on user pages).
Signed-off-by: Sage Weil <sage@newdream.net>
This commit is contained in:
Sage Weil
parent
2817b000b0
commit
124e68e740
904
fs/ceph/file.c
Normal file
904
fs/ceph/file.c
Normal file
@ -0,0 +1,904 @@
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#include "ceph_debug.h"
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#include <linux/sched.h>
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#include <linux/file.h>
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#include <linux/namei.h>
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#include <linux/writeback.h>
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#include "super.h"
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#include "mds_client.h"
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/*
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* Ceph file operations
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*
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* Implement basic open/close functionality, and implement
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* read/write.
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*
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* We implement three modes of file I/O:
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* - buffered uses the generic_file_aio_{read,write} helpers
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*
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* - synchronous is used when there is multi-client read/write
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* sharing, avoids the page cache, and synchronously waits for an
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* ack from the OSD.
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*
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* - direct io takes the variant of the sync path that references
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* user pages directly.
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*
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* fsync() flushes and waits on dirty pages, but just queues metadata
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* for writeback: since the MDS can recover size and mtime there is no
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* need to wait for MDS acknowledgement.
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*/
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/*
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* Prepare an open request. Preallocate ceph_cap to avoid an
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* inopportune ENOMEM later.
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*/
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static struct ceph_mds_request *
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prepare_open_request(struct super_block *sb, int flags, int create_mode)
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{
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struct ceph_client *client = ceph_sb_to_client(sb);
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struct ceph_mds_client *mdsc = &client->mdsc;
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struct ceph_mds_request *req;
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int want_auth = USE_ANY_MDS;
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int op = (flags & O_CREAT) ? CEPH_MDS_OP_CREATE : CEPH_MDS_OP_OPEN;
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if (flags & (O_WRONLY|O_RDWR|O_CREAT|O_TRUNC))
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want_auth = USE_AUTH_MDS;
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req = ceph_mdsc_create_request(mdsc, op, want_auth);
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if (IS_ERR(req))
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goto out;
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req->r_fmode = ceph_flags_to_mode(flags);
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req->r_args.open.flags = cpu_to_le32(flags);
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req->r_args.open.mode = cpu_to_le32(create_mode);
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req->r_args.open.preferred = -1;
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out:
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return req;
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}
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/*
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* initialize private struct file data.
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* if we fail, clean up by dropping fmode reference on the ceph_inode
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*/
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static int ceph_init_file(struct inode *inode, struct file *file, int fmode)
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{
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struct ceph_file_info *cf;
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int ret = 0;
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switch (inode->i_mode & S_IFMT) {
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case S_IFREG:
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case S_IFDIR:
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dout("init_file %p %p 0%o (regular)\n", inode, file,
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inode->i_mode);
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cf = kmem_cache_alloc(ceph_file_cachep, GFP_NOFS | __GFP_ZERO);
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if (cf == NULL) {
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ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
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return -ENOMEM;
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}
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cf->fmode = fmode;
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cf->next_offset = 2;
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file->private_data = cf;
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BUG_ON(inode->i_fop->release != ceph_release);
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break;
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case S_IFLNK:
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dout("init_file %p %p 0%o (symlink)\n", inode, file,
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inode->i_mode);
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ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
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break;
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default:
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dout("init_file %p %p 0%o (special)\n", inode, file,
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inode->i_mode);
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/*
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* we need to drop the open ref now, since we don't
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* have .release set to ceph_release.
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*/
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ceph_put_fmode(ceph_inode(inode), fmode); /* clean up */
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BUG_ON(inode->i_fop->release == ceph_release);
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/* call the proper open fop */
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ret = inode->i_fop->open(inode, file);
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}
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return ret;
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}
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/*
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* If the filp already has private_data, that means the file was
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* already opened by intent during lookup, and we do nothing.
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*
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* If we already have the requisite capabilities, we can satisfy
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* the open request locally (no need to request new caps from the
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* MDS). We do, however, need to inform the MDS (asynchronously)
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* if our wanted caps set expands.
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*/
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int ceph_open(struct inode *inode, struct file *file)
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{
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struct ceph_inode_info *ci = ceph_inode(inode);
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struct ceph_client *client = ceph_sb_to_client(inode->i_sb);
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struct ceph_mds_client *mdsc = &client->mdsc;
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struct ceph_mds_request *req;
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struct ceph_file_info *cf = file->private_data;
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struct inode *parent_inode = file->f_dentry->d_parent->d_inode;
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int err;
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int flags, fmode, wanted;
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if (cf) {
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dout("open file %p is already opened\n", file);
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return 0;
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}
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/* filter out O_CREAT|O_EXCL; vfs did that already. yuck. */
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flags = file->f_flags & ~(O_CREAT|O_EXCL);
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if (S_ISDIR(inode->i_mode))
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flags = O_DIRECTORY; /* mds likes to know */
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dout("open inode %p ino %llx.%llx file %p flags %d (%d)\n", inode,
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ceph_vinop(inode), file, flags, file->f_flags);
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fmode = ceph_flags_to_mode(flags);
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wanted = ceph_caps_for_mode(fmode);
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/* snapped files are read-only */
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if (ceph_snap(inode) != CEPH_NOSNAP && (file->f_mode & FMODE_WRITE))
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return -EROFS;
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/* trivially open snapdir */
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if (ceph_snap(inode) == CEPH_SNAPDIR) {
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spin_lock(&inode->i_lock);
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__ceph_get_fmode(ci, fmode);
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spin_unlock(&inode->i_lock);
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return ceph_init_file(inode, file, fmode);
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}
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/*
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* No need to block if we have any caps. Update wanted set
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* asynchronously.
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*/
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spin_lock(&inode->i_lock);
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if (__ceph_is_any_real_caps(ci)) {
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int mds_wanted = __ceph_caps_mds_wanted(ci);
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int issued = __ceph_caps_issued(ci, NULL);
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dout("open %p fmode %d want %s issued %s using existing\n",
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inode, fmode, ceph_cap_string(wanted),
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ceph_cap_string(issued));
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__ceph_get_fmode(ci, fmode);
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spin_unlock(&inode->i_lock);
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/* adjust wanted? */
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if ((issued & wanted) != wanted &&
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(mds_wanted & wanted) != wanted &&
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ceph_snap(inode) != CEPH_SNAPDIR)
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ceph_check_caps(ci, 0, NULL);
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return ceph_init_file(inode, file, fmode);
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} else if (ceph_snap(inode) != CEPH_NOSNAP &&
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(ci->i_snap_caps & wanted) == wanted) {
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__ceph_get_fmode(ci, fmode);
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spin_unlock(&inode->i_lock);
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return ceph_init_file(inode, file, fmode);
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}
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spin_unlock(&inode->i_lock);
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dout("open fmode %d wants %s\n", fmode, ceph_cap_string(wanted));
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req = prepare_open_request(inode->i_sb, flags, 0);
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if (IS_ERR(req)) {
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err = PTR_ERR(req);
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goto out;
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}
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req->r_inode = igrab(inode);
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req->r_num_caps = 1;
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err = ceph_mdsc_do_request(mdsc, parent_inode, req);
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if (!err)
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err = ceph_init_file(inode, file, req->r_fmode);
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ceph_mdsc_put_request(req);
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dout("open result=%d on %llx.%llx\n", err, ceph_vinop(inode));
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out:
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return err;
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}
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/*
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* Do a lookup + open with a single request.
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*
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* If this succeeds, but some subsequent check in the vfs
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* may_open() fails, the struct *file gets cleaned up (i.e.
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* ceph_release gets called). So fear not!
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*/
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/*
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* flags
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* path_lookup_open -> LOOKUP_OPEN
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* path_lookup_create -> LOOKUP_OPEN|LOOKUP_CREATE
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*/
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struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
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struct nameidata *nd, int mode,
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int locked_dir)
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{
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struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
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struct ceph_mds_client *mdsc = &client->mdsc;
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struct file *file = nd->intent.open.file;
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struct inode *parent_inode = get_dentry_parent_inode(file->f_dentry);
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struct ceph_mds_request *req;
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int err;
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int flags = nd->intent.open.flags - 1; /* silly vfs! */
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dout("ceph_lookup_open dentry %p '%.*s' flags %d mode 0%o\n",
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dentry, dentry->d_name.len, dentry->d_name.name, flags, mode);
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/* do the open */
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req = prepare_open_request(dir->i_sb, flags, mode);
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if (IS_ERR(req))
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return ERR_PTR(PTR_ERR(req));
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req->r_dentry = dget(dentry);
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req->r_num_caps = 2;
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if (flags & O_CREAT) {
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req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
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req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
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}
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req->r_locked_dir = dir; /* caller holds dir->i_mutex */
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err = ceph_mdsc_do_request(mdsc, parent_inode, req);
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dentry = ceph_finish_lookup(req, dentry, err);
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if (!err && (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 (!err)
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err = ceph_init_file(req->r_dentry->d_inode, file,
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req->r_fmode);
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ceph_mdsc_put_request(req);
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dout("ceph_lookup_open result=%p\n", dentry);
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return dentry;
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}
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int ceph_release(struct inode *inode, struct file *file)
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{
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struct ceph_inode_info *ci = ceph_inode(inode);
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struct ceph_file_info *cf = file->private_data;
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dout("release inode %p file %p\n", inode, file);
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ceph_put_fmode(ci, cf->fmode);
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if (cf->last_readdir)
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ceph_mdsc_put_request(cf->last_readdir);
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kfree(cf->last_name);
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kfree(cf->dir_info);
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dput(cf->dentry);
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kmem_cache_free(ceph_file_cachep, cf);
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return 0;
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}
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/*
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* build a vector of user pages
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*/
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static struct page **get_direct_page_vector(const char __user *data,
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int num_pages,
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loff_t off, size_t len)
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{
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struct page **pages;
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int rc;
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pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
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if (!pages)
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return ERR_PTR(-ENOMEM);
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down_read(¤t->mm->mmap_sem);
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rc = get_user_pages(current, current->mm, (unsigned long)data,
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num_pages, 0, 0, pages, NULL);
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up_read(¤t->mm->mmap_sem);
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if (rc < 0)
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goto fail;
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return pages;
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fail:
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kfree(pages);
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return ERR_PTR(rc);
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}
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static void put_page_vector(struct page **pages, int num_pages)
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{
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int i;
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for (i = 0; i < num_pages; i++)
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put_page(pages[i]);
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kfree(pages);
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}
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void ceph_release_page_vector(struct page **pages, int num_pages)
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{
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int i;
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for (i = 0; i < num_pages; i++)
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__free_pages(pages[i], 0);
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kfree(pages);
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}
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/*
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* allocate a vector new pages
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*/
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static struct page **alloc_page_vector(int num_pages)
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{
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struct page **pages;
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int i;
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pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
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if (!pages)
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return ERR_PTR(-ENOMEM);
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for (i = 0; i < num_pages; i++) {
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pages[i] = alloc_page(GFP_NOFS);
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if (pages[i] == NULL) {
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ceph_release_page_vector(pages, i);
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return ERR_PTR(-ENOMEM);
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}
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}
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return pages;
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}
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/*
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* copy user data into a page vector
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*/
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static int copy_user_to_page_vector(struct page **pages,
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const char __user *data,
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loff_t off, size_t len)
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{
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int i = 0;
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int po = off & ~PAGE_CACHE_MASK;
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int left = len;
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int l, bad;
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while (left > 0) {
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l = min_t(int, PAGE_CACHE_SIZE-po, left);
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bad = copy_from_user(page_address(pages[i]) + po, data, l);
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if (bad == l)
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return -EFAULT;
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data += l - bad;
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left -= l - bad;
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if (po) {
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po += l - bad;
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if (po == PAGE_CACHE_SIZE)
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po = 0;
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}
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}
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return len;
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}
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/*
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* copy user data from a page vector into a user pointer
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*/
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static int copy_page_vector_to_user(struct page **pages, char __user *data,
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loff_t off, size_t len)
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{
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int i = 0;
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int po = off & ~PAGE_CACHE_MASK;
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int left = len;
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int l, bad;
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while (left > 0) {
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l = min_t(int, left, PAGE_CACHE_SIZE-po);
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bad = copy_to_user(data, page_address(pages[i]) + po, l);
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if (bad == l)
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return -EFAULT;
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data += l - bad;
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left -= l - bad;
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if (po) {
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po += l - bad;
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if (po == PAGE_CACHE_SIZE)
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po = 0;
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}
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i++;
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}
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return len;
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}
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/*
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* Zero an extent within a page vector. Offset is relative to the
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* start of the first page.
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*/
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static void zero_page_vector_range(int off, int len, struct page **pages)
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{
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int i = off >> PAGE_CACHE_SHIFT;
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dout("zero_page_vector_page %u~%u\n", off, len);
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BUG_ON(len < PAGE_CACHE_SIZE);
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/* leading partial page? */
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if (off & ~PAGE_CACHE_MASK) {
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dout("zeroing %d %p head from %d\n", i, pages[i],
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(int)(off & ~PAGE_CACHE_MASK));
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zero_user_segment(pages[i], off & ~PAGE_CACHE_MASK,
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PAGE_CACHE_SIZE);
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off += PAGE_CACHE_SIZE;
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off &= PAGE_CACHE_MASK;
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i++;
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}
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while (len >= PAGE_CACHE_SIZE) {
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dout("zeroing %d %p\n", i, pages[i]);
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zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
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off += PAGE_CACHE_SIZE;
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len -= PAGE_CACHE_SIZE;
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i++;
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}
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/* trailing partial page? */
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if (len) {
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dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
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zero_user_segment(pages[i], 0, len);
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}
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}
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/*
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* Read a range of bytes striped over one or more objects. Iterate over
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* objects we stripe over. (That's not atomic, but good enough for now.)
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*
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* If we get a short result from the OSD, check against i_size; we need to
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* only return a short read to the caller if we hit EOF.
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*/
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static int striped_read(struct inode *inode,
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u64 off, u64 len,
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struct page **pages, int num_pages)
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{
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struct ceph_client *client = ceph_inode_to_client(inode);
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struct ceph_inode_info *ci = ceph_inode(inode);
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u64 pos, this_len;
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int page_off = off & ~PAGE_CACHE_SIZE; /* first byte's offset in page */
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int left, pages_left;
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int read;
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struct page **page_pos;
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int ret;
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bool hit_stripe, was_short;
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/*
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* we may need to do multiple reads. not atomic, unfortunately.
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*/
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pos = off;
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left = len;
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page_pos = pages;
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pages_left = num_pages;
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||||
read = 0;
|
||||
|
||||
more:
|
||||
this_len = left;
|
||||
ret = ceph_osdc_readpages(&client->osdc, ceph_vino(inode),
|
||||
&ci->i_layout, pos, &this_len,
|
||||
ci->i_truncate_seq,
|
||||
ci->i_truncate_size,
|
||||
page_pos, pages_left);
|
||||
hit_stripe = this_len < left;
|
||||
was_short = ret >= 0 && ret < this_len;
|
||||
if (ret == -ENOENT)
|
||||
ret = 0;
|
||||
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) {
|
||||
int didpages =
|
||||
((pos & ~PAGE_CACHE_MASK) + ret) >> PAGE_CACHE_SHIFT;
|
||||
|
||||
if (read < pos - off) {
|
||||
dout(" zero gap %llu to %llu\n", off + read, pos);
|
||||
zero_page_vector_range(page_off + read,
|
||||
pos - off - read, pages);
|
||||
}
|
||||
pos += ret;
|
||||
read = pos - off;
|
||||
left -= ret;
|
||||
page_pos += didpages;
|
||||
pages_left -= didpages;
|
||||
|
||||
/* hit stripe? */
|
||||
if (left && hit_stripe)
|
||||
goto more;
|
||||
}
|
||||
|
||||
if (was_short) {
|
||||
/* was original extent fully inside i_size? */
|
||||
if (pos + left <= inode->i_size) {
|
||||
dout("zero tail\n");
|
||||
zero_page_vector_range(page_off + read, len - read,
|
||||
pages);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* check i_size */
|
||||
ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
|
||||
if (ret < 0)
|
||||
goto out;
|
||||
|
||||
/* hit EOF? */
|
||||
if (pos >= inode->i_size)
|
||||
goto out;
|
||||
|
||||
goto more;
|
||||
}
|
||||
|
||||
out:
|
||||
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,
|
||||
unsigned len, loff_t *poff)
|
||||
{
|
||||
struct inode *inode = file->f_dentry->d_inode;
|
||||
struct page **pages;
|
||||
u64 off = *poff;
|
||||
int num_pages = calc_pages_for(off, len);
|
||||
int ret;
|
||||
|
||||
dout("sync_read on file %p %llu~%u %s\n", file, off, len,
|
||||
(file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
|
||||
|
||||
if (file->f_flags & O_DIRECT) {
|
||||
pages = get_direct_page_vector(data, num_pages, off, len);
|
||||
|
||||
/*
|
||||
* flush any page cache pages in this range. this
|
||||
* will make concurrent normal and O_DIRECT io slow,
|
||||
* but it will at least behave sensibly when they are
|
||||
* in sequence.
|
||||
*/
|
||||
filemap_write_and_wait(inode->i_mapping);
|
||||
} else {
|
||||
pages = alloc_page_vector(num_pages);
|
||||
}
|
||||
if (IS_ERR(pages))
|
||||
return PTR_ERR(pages);
|
||||
|
||||
ret = striped_read(inode, off, len, pages, num_pages);
|
||||
|
||||
if (ret >= 0 && (file->f_flags & O_DIRECT) == 0)
|
||||
ret = copy_page_vector_to_user(pages, data, off, ret);
|
||||
if (ret >= 0)
|
||||
*poff = off + ret;
|
||||
|
||||
if (file->f_flags & O_DIRECT)
|
||||
put_page_vector(pages, num_pages);
|
||||
else
|
||||
ceph_release_page_vector(pages, num_pages);
|
||||
dout("sync_read result %d\n", ret);
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* Write commit callback, called if we requested both an ACK and
|
||||
* ONDISK commit reply from the OSD.
|
||||
*/
|
||||
static void sync_write_commit(struct ceph_osd_request *req,
|
||||
struct ceph_msg *msg)
|
||||
{
|
||||
struct ceph_inode_info *ci = ceph_inode(req->r_inode);
|
||||
|
||||
dout("sync_write_commit %p tid %llu\n", req, req->r_tid);
|
||||
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);
|
||||
}
|
||||
|
||||
/*
|
||||
* 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,
|
||||
size_t left, loff_t *offset)
|
||||
{
|
||||
struct inode *inode = file->f_dentry->d_inode;
|
||||
struct ceph_inode_info *ci = ceph_inode(inode);
|
||||
struct ceph_client *client = ceph_inode_to_client(inode);
|
||||
struct ceph_osd_request *req;
|
||||
struct page **pages;
|
||||
int num_pages;
|
||||
long long unsigned pos;
|
||||
u64 len;
|
||||
int written = 0;
|
||||
int flags;
|
||||
int do_sync = 0;
|
||||
int check_caps = 0;
|
||||
int ret;
|
||||
struct timespec mtime = CURRENT_TIME;
|
||||
|
||||
if (ceph_snap(file->f_dentry->d_inode) != CEPH_NOSNAP)
|
||||
return -EROFS;
|
||||
|
||||
dout("sync_write on file %p %lld~%u %s\n", file, *offset,
|
||||
(unsigned)left, (file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
|
||||
|
||||
if (file->f_flags & O_APPEND)
|
||||
pos = i_size_read(inode);
|
||||
else
|
||||
pos = *offset;
|
||||
|
||||
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
|
||||
do_sync = 1;
|
||||
|
||||
/*
|
||||
* we may need to do multiple writes here if we span an object
|
||||
* boundary. this isn't atomic, unfortunately. :(
|
||||
*/
|
||||
more:
|
||||
len = left;
|
||||
req = ceph_osdc_new_request(&client->osdc, &ci->i_layout,
|
||||
ceph_vino(inode), pos, &len,
|
||||
CEPH_OSD_OP_WRITE, flags,
|
||||
ci->i_snap_realm->cached_context,
|
||||
do_sync,
|
||||
ci->i_truncate_seq, ci->i_truncate_size,
|
||||
&mtime, false, 2);
|
||||
if (IS_ERR(req))
|
||||
return PTR_ERR(req);
|
||||
|
||||
num_pages = calc_pages_for(pos, len);
|
||||
|
||||
if (file->f_flags & O_DIRECT) {
|
||||
pages = get_direct_page_vector(data, num_pages, pos, len);
|
||||
if (IS_ERR(pages)) {
|
||||
ret = PTR_ERR(pages);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/*
|
||||
* throw out any page cache pages in this range. this
|
||||
* may block.
|
||||
*/
|
||||
truncate_inode_pages_range(inode->i_mapping, pos, pos+len);
|
||||
} else {
|
||||
pages = alloc_page_vector(num_pages);
|
||||
if (IS_ERR(pages)) {
|
||||
ret = PTR_ERR(pages);
|
||||
goto out;
|
||||
}
|
||||
ret = copy_user_to_page_vector(pages, data, pos, len);
|
||||
if (ret < 0) {
|
||||
ceph_release_page_vector(pages, num_pages);
|
||||
goto out;
|
||||
}
|
||||
|
||||
if ((file->f_flags & O_SYNC) == 0) {
|
||||
/* get a second commit callback */
|
||||
req->r_safe_callback = sync_write_commit;
|
||||
req->r_own_pages = 1;
|
||||
}
|
||||
}
|
||||
req->r_pages = pages;
|
||||
req->r_num_pages = num_pages;
|
||||
req->r_inode = inode;
|
||||
|
||||
ret = ceph_osdc_start_request(&client->osdc, req, false);
|
||||
if (!ret) {
|
||||
if (req->r_safe_callback) {
|
||||
/*
|
||||
* Add to inode unsafe list only after we
|
||||
* start_request so that a tid has been assigned.
|
||||
*/
|
||||
spin_lock(&ci->i_unsafe_lock);
|
||||
list_add(&ci->i_unsafe_writes, &req->r_unsafe_item);
|
||||
spin_unlock(&ci->i_unsafe_lock);
|
||||
ceph_get_cap_refs(ci, CEPH_CAP_FILE_WR);
|
||||
}
|
||||
ret = ceph_osdc_wait_request(&client->osdc, req);
|
||||
}
|
||||
|
||||
if (file->f_flags & O_DIRECT)
|
||||
put_page_vector(pages, num_pages);
|
||||
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;
|
||||
if (left)
|
||||
goto more;
|
||||
|
||||
ret = written;
|
||||
*offset = pos;
|
||||
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;
|
||||
loff_t *ppos = &iocb->ki_pos;
|
||||
size_t len = iov->iov_len;
|
||||
struct inode *inode = filp->f_dentry->d_inode;
|
||||
struct ceph_inode_info *ci = ceph_inode(inode);
|
||||
ssize_t ret;
|
||||
int got = 0;
|
||||
|
||||
dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
|
||||
inode, ceph_vinop(inode), pos, (unsigned)len, inode);
|
||||
__ceph_do_pending_vmtruncate(inode);
|
||||
ret = ceph_get_caps(ci, CEPH_CAP_FILE_RD, CEPH_CAP_FILE_CACHE,
|
||||
&got, -1);
|
||||
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));
|
||||
|
||||
if ((got & CEPH_CAP_FILE_CACHE) == 0 ||
|
||||
(iocb->ki_filp->f_flags & O_DIRECT) ||
|
||||
(inode->i_sb->s_flags & MS_SYNCHRONOUS))
|
||||
/* hmm, this isn't really async... */
|
||||
ret = ceph_sync_read(filp, iov->iov_base, len, ppos);
|
||||
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);
|
||||
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;
|
||||
struct inode *inode = file->f_dentry->d_inode;
|
||||
struct ceph_inode_info *ci = ceph_inode(inode);
|
||||
struct ceph_osd_client *osdc = &ceph_client(inode->i_sb)->osdc;
|
||||
loff_t endoff = pos + iov->iov_len;
|
||||
int got = 0;
|
||||
int ret;
|
||||
|
||||
if (ceph_snap(inode) != CEPH_NOSNAP)
|
||||
return -EROFS;
|
||||
|
||||
retry_snap:
|
||||
if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL))
|
||||
return -ENOSPC;
|
||||
__ceph_do_pending_vmtruncate(inode);
|
||||
dout("aio_write %p %llx.%llx %llu~%u getting caps. i_size %llu\n",
|
||||
inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
|
||||
inode->i_size);
|
||||
ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, CEPH_CAP_FILE_BUFFER,
|
||||
&got, endoff);
|
||||
if (ret < 0)
|
||||
goto out;
|
||||
|
||||
dout("aio_write %p %llx.%llx %llu~%u got cap refs on %s\n",
|
||||
inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
|
||||
ceph_cap_string(got));
|
||||
|
||||
if ((got & CEPH_CAP_FILE_BUFFER) == 0 ||
|
||||
(iocb->ki_filp->f_flags & O_DIRECT) ||
|
||||
(inode->i_sb->s_flags & MS_SYNCHRONOUS)) {
|
||||
ret = ceph_sync_write(file, iov->iov_base, iov->iov_len,
|
||||
&iocb->ki_pos);
|
||||
} else {
|
||||
ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
|
||||
|
||||
if ((ret >= 0 || ret == -EIOCBQUEUED) &&
|
||||
((file->f_flags & O_SYNC) || IS_SYNC(file->f_mapping->host)
|
||||
|| ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_NEARFULL)))
|
||||
ret = vfs_fsync_range(file, file->f_path.dentry,
|
||||
pos, pos + ret - 1, 1);
|
||||
}
|
||||
if (ret >= 0) {
|
||||
spin_lock(&inode->i_lock);
|
||||
__ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
|
||||
spin_unlock(&inode->i_lock);
|
||||
}
|
||||
|
||||
out:
|
||||
dout("aio_write %p %llx.%llx %llu~%u dropping cap refs on %s\n",
|
||||
inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len,
|
||||
ceph_cap_string(got));
|
||||
ceph_put_cap_refs(ci, got);
|
||||
|
||||
if (ret == -EOLDSNAPC) {
|
||||
dout("aio_write %p %llx.%llx %llu~%u got EOLDSNAPC, retrying\n",
|
||||
inode, ceph_vinop(inode), pos, (unsigned)iov->iov_len);
|
||||
goto retry_snap;
|
||||
}
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* llseek. be sure to verify file size on SEEK_END.
|
||||
*/
|
||||
static loff_t ceph_llseek(struct file *file, loff_t offset, int origin)
|
||||
{
|
||||
struct inode *inode = file->f_mapping->host;
|
||||
int ret;
|
||||
|
||||
mutex_lock(&inode->i_mutex);
|
||||
__ceph_do_pending_vmtruncate(inode);
|
||||
switch (origin) {
|
||||
case SEEK_END:
|
||||
ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
|
||||
if (ret < 0) {
|
||||
offset = ret;
|
||||
goto out;
|
||||
}
|
||||
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;
|
||||
}
|
||||
|
||||
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,
|
||||
.splice_read = generic_file_splice_read,
|
||||
.splice_write = generic_file_splice_write,
|
||||
.unlocked_ioctl = ceph_ioctl,
|
||||
.compat_ioctl = ceph_ioctl,
|
||||
};
|
||||
|
||||
Loading…
Reference in New Issue
Block a user