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26be88087a
linux-next/fs/ceph/file.c
Alex Elder 26be88087a libceph: change how "safe" callback is used 
An osd request currently has two callbacks.  They inform the
initiator of the request when we've received confirmation for the
target osd that a request was received, and when the osd indicates
all changes described by the request are durable.

The only time the second callback is used is in the ceph file system
for a synchronous write.  There's a race that makes some handling of
this case unsafe.  This patch addresses this problem.  The error
handling for this callback is also kind of gross, and this patch
changes that as well.

In ceph_sync_write(), if a safe callback is requested we want to add
the request on the ceph inode's unsafe items list.  Because items on
this list must have their tid set (by ceph_osd_start_request()), the
request added *after* the call to that function returns.  The
problem with this is that there's a race between starting the
request and adding it to the unsafe items list; the request may
already be complete before ceph_sync_write() even begins to put it
on the list.

To address this, we change the way the "safe" callback is used.
Rather than just calling it when the request is "safe", we use it to
notify the initiator the bounds (start and end) of the period during
which the request is *unsafe*.  So the initiator gets notified just
before the request gets sent to the osd (when it is "unsafe"), and
again when it's known the results are durable (it's no longer
unsafe).  The first call will get made in __send_request(), just
before the request message gets sent to the messenger for the first
time.  That function is only called by __send_queued(), which is
always called with the osd client's request mutex held.

We then have this callback function insert the request on the ceph
inode's unsafe list when we're told the request is unsafe.  This
will avoid the race because this call will be made under protection
of the osd client's request mutex.  It also nicely groups the setup
and cleanup of the state associated with managing unsafe requests.

The name of the "safe" callback field is changed to "unsafe" to
better reflect its new purpose.  It has a Boolean "unsafe" parameter
to indicate whether the request is becoming unsafe or is now safe.
Because the "msg" parameter wasn't used, we drop that.

This resolves the original problem reportedin:
    http://tracker.ceph.com/issues/4706

Reported-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
2013-05-01 21:18:52 -07:00

878 lines
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#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 "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)
{
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;
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);
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|O_TRUNC))
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;
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;
/* do the open */
req = prepare_open_request(dir->i_sb, flags, mode);
if (IS_ERR(req))
return PTR_ERR(req);
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 */
err = ceph_mdsc_do_request(mdsc,
(flags & (O_CREAT|O_TRUNC)) ? dir : NULL,
req);
if (err)
goto out_err;
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_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);
if (req->r_op == CEPH_MDS_OP_CREATE && req->r_reply_info.has_create_ino) {
*opened |= FILE_CREATED;
}
err = finish_open(file, dentry, ceph_open, opened);
}
out_err:
ceph_mdsc_put_request(req);
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;
int io_align, page_align;
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;
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~%u (read %u) got %d%s%s\n", pos, left, read,
ret, hit_stripe ? " HITSTRIPE" : "", was_short ? " SHORT" : "");
if (ret > 0) {
int didpages = (page_align + ret) >> PAGE_CACHE_SHIFT;
if (read < pos - off) {
dout(" zero gap %llu to %llu\n", off + read, pos);
ceph_zero_page_vector_range(page_align + 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) {
/* 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);
ceph_zero_page_vector_range(page_align + read, left,
pages);
read += left;
}
}
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, int *checkeof)
{
struct inode *inode = file_inode(file);
struct page **pages;
u64 off = *poff;
int num_pages, 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) {
num_pages = calc_pages_for((unsigned long)data, len);
pages = ceph_get_direct_page_vector(data, num_pages, true);
} 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);
/*
* 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(inode->i_mapping);
if (ret < 0)
goto done;
ret = striped_read(inode, off, len, pages, num_pages, checkeof,
file->f_flags & O_DIRECT,
(unsigned long)data & ~PAGE_MASK);
if (ret >= 0 && (file->f_flags & O_DIRECT) == 0)
ret = ceph_copy_page_vector_to_user(pages, data, off, ret);
if (ret >= 0)
*poff = off + ret;
done:
if (file->f_flags & O_DIRECT)
ceph_put_page_vector(pages, num_pages, true);
else
ceph_release_page_vector(pages, num_pages);
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
* 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_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;
int num_ops = 1;
struct page **pages;
int num_pages;
long long unsigned pos;
u64 len;
int written = 0;
int flags;
int check_caps = 0;
int page_align, io_align;
unsigned long buf_align;
int ret;
struct timespec mtime = CURRENT_TIME;
bool own_pages = false;
if (ceph_snap(file_inode(file)) != 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;
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);
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
num_ops++; /* Also include a 'startsync' command. */
/*
* we may need to do multiple writes here if we span an object
* boundary. this isn't atomic, unfortunately. :(
*/
more:
io_align = pos & ~PAGE_MASK;
buf_align = (unsigned long)data & ~PAGE_MASK;
len = left;
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, num_ops,
CEPH_OSD_OP_WRITE, flags, snapc,
ci->i_truncate_seq, ci->i_truncate_size,
false);
if (IS_ERR(req))
return PTR_ERR(req);
/* 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);
if (file->f_flags & O_DIRECT) {
pages = ceph_get_direct_page_vector(data, num_pages, false);
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) | (PAGE_CACHE_SIZE-1));
} else {
pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
if (IS_ERR(pages)) {
ret = PTR_ERR(pages);
goto out;
}
ret = ceph_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_unsafe_callback = ceph_sync_write_unsafe;
req->r_inode = inode;
own_pages = true;
}
}
osd_req_op_extent_osd_data_pages(req, 0, true, pages, len,
page_align, false, own_pages);
/* 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);
if (file->f_flags & O_DIRECT)
ceph_put_page_vector(pages, num_pages, false);
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;
data += 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;
struct ceph_file_info *fi = filp->private_data;
loff_t *ppos = &iocb->ki_pos;
size_t len = iov->iov_len;
struct inode *inode = file_inode(filp);
struct ceph_inode_info *ci = ceph_inode(inode);
void __user *base = iov->iov_base;
ssize_t ret;
int want, got = 0;
int checkeof = 0, read = 0;
dout("aio_read %p %llx.%llx %llu~%u trying to get caps on %p\n",
inode, ceph_vinop(inode), pos, (unsigned)len, inode);
again:
__ceph_do_pending_vmtruncate(inode, true);
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)
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|CEPH_CAP_FILE_LAZYIO)) == 0 ||
(iocb->ki_filp->f_flags & O_DIRECT) ||
(inode->i_sb->s_flags & MS_SYNCHRONOUS) ||
(fi->flags & CEPH_F_SYNC))
/* hmm, this isn't really async... */
ret = ceph_sync_read(filp, base, len, ppos, &checkeof);
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);
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) {
dout("aio_read sync_read hit hole, ppos %lld < size %lld, reading more\n", *ppos, inode->i_size);
read += ret;
base += 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_aio_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
{
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;
loff_t endoff = pos + iov->iov_len;
int want, got = 0;
int ret, err;
if (ceph_snap(inode) != CEPH_NOSNAP)
return -EROFS;
sb_start_write(inode->i_sb);
retry_snap:
if (ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL)) {
ret = -ENOSPC;
goto out;
}
__ceph_do_pending_vmtruncate(inode, true);
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);
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 out_put;
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|CEPH_CAP_FILE_LAZYIO)) == 0 ||
(iocb->ki_filp->f_flags & O_DIRECT) ||
(inode->i_sb->s_flags & MS_SYNCHRONOUS) ||
(fi->flags & CEPH_F_SYNC)) {
ret = ceph_sync_write(file, iov->iov_base, iov->iov_len,
&iocb->ki_pos);
} else {
mutex_lock(&inode->i_mutex);
ret = __generic_file_aio_write(iocb, iov, nr_segs,
&iocb->ki_pos);
mutex_unlock(&inode->i_mutex);
}
if (ret >= 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);
}
out_put:
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 >= 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 + ret - 1, 1);
if (err < 0)
ret = err;
}
out:
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;
}
sb_end_write(inode->i_sb);
return ret;
}
/*
* 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);
__ceph_do_pending_vmtruncate(inode, false);
if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
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;
}
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,
.lock = ceph_lock,
.flock = ceph_flock,
.splice_read = generic_file_splice_read,
.splice_write = generic_file_splice_write,
.unlocked_ioctl = ceph_ioctl,
.compat_ioctl = ceph_ioctl,
};
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