- 根目录:
- fs
- ceph
- file.c
#include <linux/ceph/ceph_debug.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/writeback.h>
#include <linux/aio.h>
#include <linux/falloc.h>
#include "super.h"
#include "mds_client.h"
#include "cache.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)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
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;
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
switch (inode->i_mode & S_IFMT) {
case S_IFREG:
/* First file open request creates the cookie, we want to keep
* this cookie around for the filetime of the inode as not to
* have to worry about fscache register / revoke / operation
* races.
*
* Also, if we know the operation is going to invalidate data
* (non readonly) just nuke the cache right away.
*/
ceph_fscache_register_inode_cookie(mdsc->fsc, ci);
if ((fmode & CEPH_FILE_MODE_WR))
ceph_fscache_invalidate(inode);
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);
struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct ceph_file_info *cf = file->private_data;
struct inode *parent_inode = NULL;
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) {
spin_lock(&ci->i_ceph_lock);
__ceph_get_fmode(ci, fmode);
spin_unlock(&ci->i_ceph_lock);
return ceph_init_file(inode, file, fmode);
}
/*
* No need to block if we have caps on the auth MDS (for
* write) or any MDS (for read). Update wanted set
* asynchronously.
*/
spin_lock(&ci->i_ceph_lock);
if (__ceph_is_any_real_caps(ci) &&
(((fmode & CEPH_FILE_MODE_WR) == 0) || ci->i_auth_cap)) {
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);
spin_unlock(&ci->i_ceph_lock);
/* 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);
spin_unlock(&ci->i_ceph_lock);
return ceph_init_file(inode, file, fmode);
}
spin_unlock(&ci->i_ceph_lock);
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;
}
req->r_inode = inode;
ihold(inode);
req->r_num_caps = 1;
if (flags & O_CREAT)
parent_inode = ceph_get_dentry_parent_inode(file->f_dentry);
err = ceph_mdsc_do_request(mdsc, parent_inode, req);
iput(parent_inode);
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;
}
/*
* Do a lookup + open with a single request. If we get a non-existent
* file or symlink, return 1 so the VFS can retry.
*/
int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
struct file *file, unsigned flags, umode_t mode,
int *opened)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct dentry *dn;
struct ceph_acls_info acls = {};
int err;
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;
if (flags & O_CREAT) {
err = ceph_pre_init_acls(dir, &mode, &acls);
if (err < 0)
return err;
}
/* do the open */
req = prepare_open_request(dir->i_sb, flags, mode);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out_acl;
}
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;
if (acls.pagelist) {
req->r_pagelist = acls.pagelist;
acls.pagelist = NULL;
}
}
req->r_locked_dir = dir; /* caller holds dir->i_mutex */
err = ceph_mdsc_do_request(mdsc,
(flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
req);
if (err)
goto out_req;
err = ceph_handle_snapdir(req, dentry, err);
if (err == 0 && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
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_req;
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);
if (req->r_op == CEPH_MDS_OP_CREATE && req->r_reply_info.has_create_ino) {
ceph_init_inode_acls(dentry->d_inode, &acls);
*opened |= FILE_CREATED;
}
err = finish_open(file, dentry, ceph_open, opened);
}
out_req:
if (!req->r_err && req->r_target_inode)
ceph_put_fmode(ceph_inode(req->r_target_inode), req->r_fmode);
ceph_mdsc_put_request(req);
out_acl:
ceph_release_acls_info(&acls);
dout("atomic_open result=%d\n", err);
return err;
}
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);
/* wake up anyone waiting for caps on this inode */
wake_up_all(&ci->i_cap_wq);
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,
struct page **pages, int num_pages,
int *checkeof, bool o_direct,
unsigned long buf_align)
{
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_inode_info *ci = ceph_inode(inode);
u64 pos, this_len, left;
int io_align, page_align;
int 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;
io_align = off & ~PAGE_MASK;
more:
if (o_direct)
page_align = (pos - io_align + buf_align) & ~PAGE_MASK;
else
page_align = pos & ~PAGE_MASK;
this_len = left;
ret = ceph_osdc_readpages(&fsc->client->osdc, ceph_vino(inode),
&ci->i_layout, pos, &this_len,
ci->i_truncate_seq,
ci->i_truncate_size,
page_pos, pages_left, page_align);
if (ret == -ENOENT)
ret = 0;
hit_stripe = this_len < left;
was_short = ret >= 0 && ret < this_len;
dout("striped_read %llu~%llu (read %u) got %d%s%s\n", pos, left, read,
ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");
if (ret >= 0) {
int didpages;
if (was_short && (pos + ret < inode->i_size)) {
u64 tmp = min(this_len - ret,
inode->i_size - pos - ret);
dout(" zero gap %llu to %llu\n",
pos + ret, pos + ret + tmp);
ceph_zero_page_vector_range(page_align + read + ret,
tmp, pages);
ret += tmp;
}
didpages = (page_align + ret) >> PAGE_CACHE_SHIFT;
pos += ret;
read = pos - off;
left -= ret;
page_pos += didpages;
pages_left -= didpages;
/* hit stripe and need continue*/
if (left && hit_stripe && pos < inode->i_size)
goto more;
}
if (read > 0) {
ret = read;
/* did we bounce off eof? */
if (pos + left > inode->i_size)
*checkeof = 1;
}
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 kiocb *iocb, struct iov_iter *i,
int *checkeof)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct page **pages;
u64 off = iocb->ki_pos;
int num_pages, ret;
size_t len = iov_iter_count(i);
dout("sync_read on file %p %llu~%u %s\n", file, off,
(unsigned)len,
(file->f_flags & O_DIRECT) ? "O_DIRECT" : "");
if (!len)
return 0;
/*
* 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.
*/
ret = filemap_write_and_wait_range(inode->i_mapping, off,
off + len);
if (ret < 0)
return ret;
if (file->f_flags & O_DIRECT) {
while (iov_iter_count(i)) {
size_t start;
ssize_t n;
n = iov_iter_get_pages_alloc(i, &pages, INT_MAX, &start);
if (n < 0)
return n;
num_pages = (n + start + PAGE_SIZE - 1) / PAGE_SIZE;
ret = striped_read(inode, off, n,
pages, num_pages, checkeof,
1, start);
ceph_put_page_vector(pages, num_pages, true);
if (ret <= 0)
break;
off += ret;
iov_iter_advance(i, ret);
if (ret < n)
break;
}
} else {
num_pages = calc_pages_for(off, len);
pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
if (IS_ERR(pages))
return PTR_ERR(pages);
ret = striped_read(inode, off, len, pages,
num_pages, checkeof, 0, 0);
if (ret > 0) {
int l, k = 0;
size_t left = ret;
while (left) {
size_t page_off = off & ~PAGE_MASK;
size_t copy = min_t(size_t,
PAGE_SIZE - page_off, left);
l = copy_page_to_iter(pages[k++], page_off,
copy, i);
off += l;
left -= l;
if (l < copy)
break;
}
}
ceph_release_page_vector(pages, num_pages);
}
if (off > iocb->ki_pos) {
ret = off - iocb->ki_pos;
iocb->ki_pos = off;
}
dout("sync_read result %d\n", ret);
return ret;
}
/*
* 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.
*/
static void ceph_sync_write_unsafe(struct ceph_osd_request *req, bool unsafe)
{
struct ceph_inode_info *ci = ceph_inode(req->r_inode);
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);
}
}
/*
* Synchronous write, straight from __user pointer or user pages.
*
* 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_direct_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_snap_context *snapc;
struct ceph_vino vino;
struct ceph_osd_request *req;
struct page **pages;
int num_pages;
int written = 0;
int flags;
int check_caps = 0;
int ret;
struct timespec mtime = CURRENT_TIME;
size_t count = iov_iter_count(from);
if (ceph_snap(file_inode(file)) != CEPH_NOSNAP)
return -EROFS;
dout("sync_direct_write on file %p %lld~%u\n", file, pos,
(unsigned)count);
ret = filemap_write_and_wait_range(inode->i_mapping, pos, pos + count);
if (ret < 0)
return ret;
ret = invalidate_inode_pages2_range(inode->i_mapping,
pos >> PAGE_CACHE_SHIFT,
(pos + count) >> PAGE_CACHE_SHIFT);
if (ret < 0)
dout("invalidate_inode_pages2_range returned %d\n", ret);
flags = CEPH_OSD_FLAG_ORDERSNAP |
CEPH_OSD_FLAG_ONDISK |
CEPH_OSD_FLAG_WRITE;
while (iov_iter_count(from) > 0) {
u64 len = iov_iter_single_seg_count(from);
size_t start;
ssize_t n;
snapc = ci->i_snap_realm->cached_context;
vino = ceph_vino(inode);
req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
vino, pos, &len,
2,/*include a 'startsync' command*/
CEPH_OSD_OP_WRITE, flags, snapc,
ci->i_truncate_seq,
ci->i_truncate_size,
false);
if (IS_ERR(req)) {
ret = PTR_ERR(req);
break;
}
n = iov_iter_get_pages_alloc(from, &pages, len, &start);
if (unlikely(n < 0)) {
ret = n;
ceph_osdc_put_request(req);
break;
}
num_pages = (n + start + PAGE_SIZE - 1) / PAGE_SIZE;
/*
* throw out any page cache pages in this range. this
* may block.
*/
truncate_inode_pages_range(inode->i_mapping, pos,
(pos+n) | (PAGE_CACHE_SIZE-1));
osd_req_op_extent_osd_data_pages(req, 0, pages, n, start,
false, false);
/* BUG_ON(vino.snap != CEPH_NOSNAP); */
ceph_osdc_build_request(req, pos, snapc, vino.snap, &mtime);
ret = ceph_osdc_start_request(&fsc->client->osdc, req, false);
if (!ret)
ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
ceph_put_page_vector(pages, num_pages, false);
ceph_osdc_put_request(req);
if (ret)
break;
pos += n;
written += n;
iov_iter_advance(from, n);
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);
}
}
if (ret != -EOLDSNAPC && written > 0) {
iocb->ki_pos = pos;
ret = written;
}
return ret;
}
/*
* Synchronous write, straight from __user pointer or user pages.
*
* 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 kiocb *iocb, struct iov_iter *from, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_snap_context *snapc;
struct ceph_vino vino;
struct ceph_osd_request *req;
struct page **pages;
u64 len;
int num_pages;
int written = 0;
int flags;
int check_caps = 0;
int ret;
struct timespec mtime = CURRENT_TIME;
size_t count = iov_iter_count(from);
if (ceph_snap(file_inode(file)) != CEPH_NOSNAP)
return -EROFS;
dout("sync_write on file %p %lld~%u\n", file, pos, (unsigned)count);
ret = filemap_write_and_wait_range(inode->i_mapping, pos, pos + count);
if (ret < 0)
return ret;
ret = invalidate_inode_pages2_range(inode->i_mapping,
pos >> PAGE_CACHE_SHIFT,
(pos + count) >> PAGE_CACHE_SHIFT);
if (ret < 0)
dout("invalidate_inode_pages2_range returned %d\n", ret);
flags = CEPH_OSD_FLAG_ORDERSNAP |
CEPH_OSD_FLAG_ONDISK |
CEPH_OSD_FLAG_WRITE |
CEPH_OSD_FLAG_ACK;
while ((len = iov_iter_count(from)) > 0) {
size_t left;
int n;
snapc = ci->i_snap_realm->cached_context;
vino = ceph_vino(inode);
req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
vino, pos, &len, 1,
CEPH_OSD_OP_WRITE, flags, snapc,
ci->i_truncate_seq,
ci->i_truncate_size,
false);
if (IS_ERR(req)) {
ret = PTR_ERR(req);
break;
}
/*
* write from beginning of first page,
* regardless of io alignment
*/
num_pages = (len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
if (IS_ERR(pages)) {
ret = PTR_ERR(pages);
goto out;
}
left = len;
for (n = 0; n < num_pages; n++) {
size_t plen = min_t(size_t, left, PAGE_SIZE);
ret = copy_page_from_iter(pages[n], 0, plen, from);
if (ret != plen) {
ret = -EFAULT;
break;
}
left -= ret;
}
if (ret < 0) {
ceph_release_page_vector(pages, num_pages);
goto out;
}
/* get a second commit callback */
req->r_unsafe_callback = ceph_sync_write_unsafe;
req->r_inode = inode;
osd_req_op_extent_osd_data_pages(req, 0, pages, len, 0,
false, true);
/* BUG_ON(vino.snap != CEPH_NOSNAP); */
ceph_osdc_build_request(req, pos, snapc, vino.snap, &mtime);
ret = ceph_osdc_start_request(&fsc->client->osdc, req, false);
if (!ret)
ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
out:
ceph_osdc_put_request(req);
if (ret == 0) {
pos += len;
written += len;
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);
}
} else
break;
}
if (ret != -EOLDSNAPC && written > 0) {
ret = written;
iocb->ki_pos = pos;
}
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_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
struct file *filp = iocb->ki_filp;
struct ceph_file_info *fi = filp->private_data;
size_t len = iocb->ki_nbytes;
struct inode *inode = file_inode(filp);
struct ceph_inode_info *ci = ceph_inode(inode);
ssize_t ret;
int want, got = 0;
int checkeof = 0, read = 0;
again:
dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len, inode);
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);
if (ret < 0)
return ret;
if ((got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0 ||
(iocb->ki_filp->f_flags & O_DIRECT) ||
(fi->flags & CEPH_F_SYNC)) {
dout("aio_sync_read %p %llx.%llx %llu~%u got cap refs on %s\n",
inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
ceph_cap_string(got));
/* hmm, this isn't really async... */
ret = ceph_sync_read(iocb, to, &checkeof);
} else {
dout("aio_read %p %llx.%llx %llu~%u got cap refs on %s\n",
inode, ceph_vinop(inode), iocb->ki_pos, (unsigned)len,
ceph_cap_string(got));
ret = generic_file_read_iter(iocb, to);
}
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);
if (checkeof && ret >= 0) {
int statret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);
/* hit EOF or hole? */
if (statret == 0 && iocb->ki_pos < inode->i_size &&
ret < len) {
dout("sync_read hit hole, ppos %lld < size %lld"
", reading more\n", iocb->ki_pos,
inode->i_size);
read += ret;
len -= ret;
checkeof = 0;
goto again;
}
}
if (ret >= 0)
ret += read;
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_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct ceph_file_info *fi = file->private_data;
struct inode *inode = file_inode(file);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_osd_client *osdc =
&ceph_sb_to_client(inode->i_sb)->client->osdc;
ssize_t count = iov_iter_count(from), written = 0;
int err, want, got;
loff_t pos = iocb->ki_pos;
if (ceph_snap(inode) != CEPH_NOSNAP)
return -EROFS;
mutex_lock(&inode->i_mutex);
/* 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;
iov_iter_truncate(from, count);
err = file_remove_suid(file);
if (err)
goto out;
err = file_update_time(file);
if (err)
goto out;
retry_snap:
if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL)) {
err = -ENOSPC;
goto out;
}
dout("aio_write %p %llx.%llx %llu~%zd getting caps. i_size %llu\n",
inode, ceph_vinop(inode), pos, count, inode->i_size);
if (fi->fmode & CEPH_FILE_MODE_LAZY)
want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
else
want = CEPH_CAP_FILE_BUFFER;
got = 0;
err = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, &got, pos + count);
if (err < 0)
goto out;
dout("aio_write %p %llx.%llx %llu~%zd got cap refs on %s\n",
inode, ceph_vinop(inode), pos, count, ceph_cap_string(got));
if ((got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO)) == 0 ||
(file->f_flags & O_DIRECT) || (fi->flags & CEPH_F_SYNC)) {
struct iov_iter data;
mutex_unlock(&inode->i_mutex);
/* we might need to revert back to that point */
data = *from;
if (file->f_flags & O_DIRECT)
written = ceph_sync_direct_write(iocb, &data, pos);
else
written = ceph_sync_write(iocb, &data, pos);
if (written == -EOLDSNAPC) {
dout("aio_write %p %llx.%llx %llu~%u"
"got EOLDSNAPC, retrying\n",
inode, ceph_vinop(inode),
pos, (unsigned)count);
mutex_lock(&inode->i_mutex);
goto retry_snap;
}
if (written > 0)
iov_iter_advance(from, written);
} else {
loff_t old_size = inode->i_size;
/*
* No need to acquire the i_truncate_mutex. Because
* the MDS revokes Fwb caps before sending truncate
* message to us. We can't get Fwb cap while there
* are pending vmtruncate. So write and vmtruncate
* can not run at the same time
*/
written = generic_perform_write(file, from, pos);
if (likely(written >= 0))
iocb->ki_pos = pos + written;
if (inode->i_size > old_size)
ceph_fscache_update_objectsize(inode);
mutex_unlock(&inode->i_mutex);
}
if (written >= 0) {
int dirty;
spin_lock(&ci->i_ceph_lock);
dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
spin_unlock(&ci->i_ceph_lock);
if (dirty)
__mark_inode_dirty(inode, dirty);
}
dout("aio_write %p %llx.%llx %llu~%u dropping cap refs on %s\n",
inode, ceph_vinop(inode), pos, (unsigned)count,
ceph_cap_string(got));
ceph_put_cap_refs(ci, got);
if (written >= 0 &&
((file->f_flags & O_SYNC) || IS_SYNC(file->f_mapping->host) ||
ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_NEARFULL))) {
err = vfs_fsync_range(file, pos, pos + written - 1, 1);
if (err < 0)
written = err;
}
goto out_unlocked;
out:
mutex_unlock(&inode->i_mutex);
out_unlocked:
current->backing_dev_info = NULL;
return written ? written : err;
}
/*
* llseek. be sure to verify file size on SEEK_END.
*/
static loff_t ceph_llseek(struct file *file, loff_t offset, int whence)
{
struct inode *inode = file->f_mapping->host;
int ret;
mutex_lock(&inode->i_mutex);
if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);
if (ret < 0) {
offset = ret;
goto out;
}
}
switch (whence) {
case SEEK_END:
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;
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;
}
offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
out:
mutex_unlock(&inode->i_mutex);
return offset;
}
static inline void ceph_zero_partial_page(
struct inode *inode, loff_t offset, unsigned size)
{
struct page *page;
pgoff_t index = offset >> PAGE_CACHE_SHIFT;
page = find_lock_page(inode->i_mapping, index);
if (page) {
wait_on_page_writeback(page);
zero_user(page, offset & (PAGE_CACHE_SIZE - 1), size);
unlock_page(page);
page_cache_release(page);
}
}
static void ceph_zero_pagecache_range(struct inode *inode, loff_t offset,
loff_t length)
{
loff_t nearly = round_up(offset, PAGE_CACHE_SIZE);
if (offset < nearly) {
loff_t size = nearly - offset;
if (length < size)
size = length;
ceph_zero_partial_page(inode, offset, size);
offset += size;
length -= size;
}
if (length >= PAGE_CACHE_SIZE) {
loff_t size = round_down(length, PAGE_CACHE_SIZE);
truncate_pagecache_range(inode, offset, offset + size - 1);
offset += size;
length -= size;
}
if (length)
ceph_zero_partial_page(inode, offset, length);
}
static int ceph_zero_partial_object(struct inode *inode,
loff_t offset, loff_t *length)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_osd_request *req;
int ret = 0;
loff_t zero = 0;
int op;
if (!length) {
op = offset ? CEPH_OSD_OP_DELETE : CEPH_OSD_OP_TRUNCATE;
length = &zero;
} else {
op = CEPH_OSD_OP_ZERO;
}
req = ceph_osdc_new_request(&fsc->client->osdc, &ci->i_layout,
ceph_vino(inode),
offset, length,
1, op,
CEPH_OSD_FLAG_WRITE |
CEPH_OSD_FLAG_ONDISK,
NULL, 0, 0, false);
if (IS_ERR(req)) {
ret = PTR_ERR(req);
goto out;
}
ceph_osdc_build_request(req, offset, NULL, ceph_vino(inode).snap,
&inode->i_mtime);
ret = ceph_osdc_start_request(&fsc->client->osdc, req, false);
if (!ret) {
ret = ceph_osdc_wait_request(&fsc->client->osdc, req);
if (ret == -ENOENT)
ret = 0;
}
ceph_osdc_put_request(req);
out:
return ret;
}
static int ceph_zero_objects(struct inode *inode, loff_t offset, loff_t length)
{
int ret = 0;
struct ceph_inode_info *ci = ceph_inode(inode);
s32 stripe_unit = ceph_file_layout_su(ci->i_layout);
s32 stripe_count = ceph_file_layout_stripe_count(ci->i_layout);
s32 object_size = ceph_file_layout_object_size(ci->i_layout);
u64 object_set_size = object_size * stripe_count;
u64 nearly, t;
/* round offset up to next period boundary */
nearly = offset + object_set_size - 1;
t = nearly;
nearly -= do_div(t, object_set_size);
while (length && offset < nearly) {
loff_t size = length;
ret = ceph_zero_partial_object(inode, offset, &size);
if (ret < 0)
return ret;
offset += size;
length -= size;
}
while (length >= object_set_size) {
int i;
loff_t pos = offset;
for (i = 0; i < stripe_count; ++i) {
ret = ceph_zero_partial_object(inode, pos, NULL);
if (ret < 0)
return ret;
pos += stripe_unit;
}
offset += object_set_size;
length -= object_set_size;
}
while (length) {
loff_t size = length;
ret = ceph_zero_partial_object(inode, offset, &size);
if (ret < 0)
return ret;
offset += size;
length -= size;
}
return ret;
}
static long ceph_fallocate(struct file *file, int mode,
loff_t offset, loff_t length)
{
struct ceph_file_info *fi = file->private_data;
struct inode *inode = file_inode(file);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_osd_client *osdc =
&ceph_inode_to_client(inode)->client->osdc;
int want, got = 0;
int dirty;
int ret = 0;
loff_t endoff = 0;
loff_t size;
if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
return -EOPNOTSUPP;
if (!S_ISREG(inode->i_mode))
return -EOPNOTSUPP;
mutex_lock(&inode->i_mutex);
if (ceph_snap(inode) != CEPH_NOSNAP) {
ret = -EROFS;
goto unlock;
}
if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL) &&
!(mode & FALLOC_FL_PUNCH_HOLE)) {
ret = -ENOSPC;
goto unlock;
}
size = i_size_read(inode);
if (!(mode & FALLOC_FL_KEEP_SIZE))
endoff = offset + length;
if (fi->fmode & CEPH_FILE_MODE_LAZY)
want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
else
want = CEPH_CAP_FILE_BUFFER;
ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, &got, endoff);
if (ret < 0)
goto unlock;
if (mode & FALLOC_FL_PUNCH_HOLE) {
if (offset < size)
ceph_zero_pagecache_range(inode, offset, length);
ret = ceph_zero_objects(inode, offset, length);
} else if (endoff > size) {
truncate_pagecache_range(inode, size, -1);
if (ceph_inode_set_size(inode, endoff))
ceph_check_caps(ceph_inode(inode),
CHECK_CAPS_AUTHONLY, NULL);
}
if (!ret) {
spin_lock(&ci->i_ceph_lock);
dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
spin_unlock(&ci->i_ceph_lock);
if (dirty)
__mark_inode_dirty(inode, dirty);
}
ceph_put_cap_refs(ci, got);
unlock:
mutex_unlock(&inode->i_mutex);
return ret;
}
const struct file_operations ceph_file_fops = {
.open = ceph_open,
.release = ceph_release,
.llseek = ceph_llseek,
.read = new_sync_read,
.write = new_sync_write,
.read_iter = ceph_read_iter,
.write_iter = ceph_write_iter,
.mmap = ceph_mmap,
.fsync = ceph_fsync,
.lock = ceph_lock,
.flock = ceph_flock,
.splice_read = generic_file_splice_read,
.splice_write = iter_file_splice_write,
.unlocked_ioctl = ceph_ioctl,
.compat_ioctl = ceph_ioctl,
.fallocate = ceph_fallocate,
};