WSL2-Linux-Kernel/fs/ceph/file.c

949 строки
25 KiB
C

#include "ceph_debug.h"
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/file.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_client *client = ceph_sb_to_client(sb);
struct ceph_mds_client *mdsc = &client->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);
req->r_args.open.preferred = cpu_to_le32(-1);
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 the filp already has private_data, that means the file was
* already opened by intent during lookup, and we do nothing.
*
* 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_client *client = ceph_sb_to_client(inode->i_sb);
struct ceph_mds_client *mdsc = &client->mdsc;
struct ceph_mds_request *req;
struct ceph_file_info *cf = file->private_data;
struct inode *parent_inode = file->f_dentry->d_parent->d_inode;
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(&inode->i_lock);
__ceph_get_fmode(ci, fmode);
spin_unlock(&inode->i_lock);
return ceph_init_file(inode, file, fmode);
}
/*
* No need to block if we have any caps. Update wanted set
* asynchronously.
*/
spin_lock(&inode->i_lock);
if (__ceph_is_any_real_caps(ci)) {
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(&inode->i_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(&inode->i_lock);
return ceph_init_file(inode, file, fmode);
}
spin_unlock(&inode->i_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 = igrab(inode);
req->r_num_caps = 1;
err = ceph_mdsc_do_request(mdsc, parent_inode, req);
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 this succeeds, but some subsequent check in the vfs
* may_open() fails, the struct *file gets cleaned up (i.e.
* ceph_release gets called). So fear not!
*/
/*
* flags
* path_lookup_open -> LOOKUP_OPEN
* path_lookup_create -> LOOKUP_OPEN|LOOKUP_CREATE
*/
struct dentry *ceph_lookup_open(struct inode *dir, struct dentry *dentry,
struct nameidata *nd, int mode,
int locked_dir)
{
struct ceph_client *client = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = &client->mdsc;
struct file *file = nd->intent.open.file;
struct inode *parent_inode = get_dentry_parent_inode(file->f_dentry);
struct ceph_mds_request *req;
int err;
int flags = nd->intent.open.flags - 1; /* silly vfs! */
dout("ceph_lookup_open dentry %p '%.*s' flags %d mode 0%o\n",
dentry, dentry->d_name.len, dentry->d_name.name, flags, mode);
/* do the open */
req = prepare_open_request(dir->i_sb, flags, mode);
if (IS_ERR(req))
return ERR_CAST(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, parent_inode, req);
dentry = ceph_finish_lookup(req, dentry, err);
if (!err && (flags & O_CREAT) && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
if (!err)
err = ceph_init_file(req->r_dentry->d_inode, file,
req->r_fmode);
ceph_mdsc_put_request(req);
dout("ceph_lookup_open result=%p\n", dentry);
return dentry;
}
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;
}
/*
* build a vector of user pages
*/
static struct page **get_direct_page_vector(const char __user *data,
int num_pages,
loff_t off, size_t len)
{
struct page **pages;
int rc;
pages = kmalloc(sizeof(*pages) * num_pages, GFP_NOFS);
if (!pages)
return ERR_PTR(-ENOMEM);
down_read(&current->mm->mmap_sem);
rc = get_user_pages(current, current->mm, (unsigned long)data,
num_pages, 0, 0, pages, NULL);
up_read(&current->mm->mmap_sem);
if (rc < 0)
goto fail;
return pages;
fail:
kfree(pages);
return ERR_PTR(rc);
}
static void put_page_vector(struct page **pages, int num_pages)
{
int i;
for (i = 0; i < num_pages; i++)
put_page(pages[i]);
kfree(pages);
}
void ceph_release_page_vector(struct page **pages, int num_pages)
{
int i;
for (i = 0; i < num_pages; i++)
__free_pages(pages[i], 0);
kfree(pages);
}
/*
* allocate a vector new pages
*/
static struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags)
{
struct page **pages;
int i;
pages = kmalloc(sizeof(*pages) * num_pages, flags);
if (!pages)
return ERR_PTR(-ENOMEM);
for (i = 0; i < num_pages; i++) {
pages[i] = __page_cache_alloc(flags);
if (pages[i] == NULL) {
ceph_release_page_vector(pages, i);
return ERR_PTR(-ENOMEM);
}
}
return pages;
}
/*
* copy user data into a page vector
*/
static int copy_user_to_page_vector(struct page **pages,
const char __user *data,
loff_t off, size_t len)
{
int i = 0;
int po = off & ~PAGE_CACHE_MASK;
int left = len;
int l, bad;
while (left > 0) {
l = min_t(int, PAGE_CACHE_SIZE-po, left);
bad = copy_from_user(page_address(pages[i]) + po, data, l);
if (bad == l)
return -EFAULT;
data += l - bad;
left -= l - bad;
po += l - bad;
if (po == PAGE_CACHE_SIZE) {
po = 0;
i++;
}
}
return len;
}
/*
* copy user data from a page vector into a user pointer
*/
static int copy_page_vector_to_user(struct page **pages, char __user *data,
loff_t off, size_t len)
{
int i = 0;
int po = off & ~PAGE_CACHE_MASK;
int left = len;
int l, bad;
while (left > 0) {
l = min_t(int, left, PAGE_CACHE_SIZE-po);
bad = copy_to_user(data, page_address(pages[i]) + po, l);
if (bad == l)
return -EFAULT;
data += l - bad;
left -= l - bad;
if (po) {
po += l - bad;
if (po == PAGE_CACHE_SIZE)
po = 0;
}
i++;
}
return len;
}
/*
* Zero an extent within a page vector. Offset is relative to the
* start of the first page.
*/
static void zero_page_vector_range(int off, int len, struct page **pages)
{
int i = off >> PAGE_CACHE_SHIFT;
off &= ~PAGE_CACHE_MASK;
dout("zero_page_vector_page %u~%u\n", off, len);
/* leading partial page? */
if (off) {
int end = min((int)PAGE_CACHE_SIZE, off + len);
dout("zeroing %d %p head from %d\n", i, pages[i],
(int)off);
zero_user_segment(pages[i], off, end);
len -= (end - off);
i++;
}
while (len >= PAGE_CACHE_SIZE) {
dout("zeroing %d %p len=%d\n", i, pages[i], len);
zero_user_segment(pages[i], 0, PAGE_CACHE_SIZE);
len -= PAGE_CACHE_SIZE;
i++;
}
/* trailing partial page? */
if (len) {
dout("zeroing %d %p tail to %d\n", i, pages[i], (int)len);
zero_user_segment(pages[i], 0, len);
}
}
/*
* 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)
{
struct ceph_client *client = ceph_inode_to_client(inode);
struct ceph_inode_info *ci = ceph_inode(inode);
u64 pos, this_len;
int page_off = off & ~PAGE_CACHE_MASK; /* first byte's offset in page */
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;
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);
read = len;
goto out;
}
/* check i_size */
*checkeof = 1;
}
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, int *checkeof)
{
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.
*/
} else {
pages = ceph_alloc_page_vector(num_pages, GFP_NOFS);
}
if (IS_ERR(pages))
return PTR_ERR(pages);
ret = filemap_write_and_wait(inode->i_mapping);
if (ret < 0)
goto done;
ret = striped_read(inode, off, len, pages, num_pages, checkeof);
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;
done:
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;
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
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 (!req)
return -ENOMEM;
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) | (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 = 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(&req->r_unsafe_item, &ci->i_unsafe_writes);
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;
struct ceph_file_info *fi = filp->private_data;
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);
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);
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))
/* 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, reading more\n");
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->f_dentry->d_inode;
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_osd_client *osdc = &ceph_sb_to_client(inode->i_sb)->osdc;
loff_t endoff = pos + iov->iov_len;
int want, got = 0;
int ret, err;
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);
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;
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)) {
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))) {
err = vfs_fsync_range(file, pos, pos + ret - 1, 1);
if (err < 0)
ret = err;
}
}
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,
.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,
};