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authorSage Weil <sage@inktank.com>2012-11-05 11:07:23 -0800
committerSage Weil <sage@inktank.com>2012-11-05 11:07:23 -0800
commit22cddde104d715600a4c218bf9224923208afe90 (patch)
tree82fc93d9c89ef41145e52ace63484047e600f866 /fs/ceph
parent4d1d0534f53863108fdea496288cb3310f88118d (diff)
ceph: Fix i_size update race
ceph_aio_write() has an optimization that marks cap EPH_CAP_FILE_WR dirty before data is copied to page cache and inode size is updated. If ceph_check_caps() flushes the dirty cap before the inode size is updated, MDS can miss the new inode size. The fix is move ceph_{get,put}_cap_refs() into ceph_write_{begin,end}() and call __ceph_mark_dirty_caps() after inode size is updated. Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com> Signed-off-by: Sage Weil <sage@inktank.com>
Diffstat (limited to 'fs/ceph')
-rw-r--r--fs/ceph/addr.c51
-rw-r--r--fs/ceph/file.c73
2 files changed, 77 insertions, 47 deletions
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 22b6e4583fa..21a07187df0 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1078,23 +1078,51 @@ static int ceph_write_begin(struct file *file, struct address_space *mapping,
struct page **pagep, void **fsdata)
{
struct inode *inode = file->f_dentry->d_inode;
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ struct ceph_file_info *fi = file->private_data;
struct page *page;
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
- int r;
+ int r, want, got = 0;
+
+ if (fi->fmode & CEPH_FILE_MODE_LAZY)
+ want = CEPH_CAP_FILE_BUFFER | CEPH_CAP_FILE_LAZYIO;
+ else
+ want = CEPH_CAP_FILE_BUFFER;
+
+ dout("write_begin %p %llx.%llx %llu~%u getting caps. i_size %llu\n",
+ inode, ceph_vinop(inode), pos, len, inode->i_size);
+ r = ceph_get_caps(ci, CEPH_CAP_FILE_WR, want, &got, pos+len);
+ if (r < 0)
+ return r;
+ dout("write_begin %p %llx.%llx %llu~%u got cap refs on %s\n",
+ inode, ceph_vinop(inode), pos, len, ceph_cap_string(got));
+ if (!(got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO))) {
+ ceph_put_cap_refs(ci, got);
+ return -EAGAIN;
+ }
do {
/* get a page */
page = grab_cache_page_write_begin(mapping, index, 0);
- if (!page)
- return -ENOMEM;
- *pagep = page;
+ if (!page) {
+ r = -ENOMEM;
+ break;
+ }
dout("write_begin file %p inode %p page %p %d~%d\n", file,
inode, page, (int)pos, (int)len);
r = ceph_update_writeable_page(file, pos, len, page);
+ if (r)
+ page_cache_release(page);
} while (r == -EAGAIN);
+ if (r) {
+ ceph_put_cap_refs(ci, got);
+ } else {
+ *pagep = page;
+ *(int *)fsdata = got;
+ }
return r;
}
@@ -1108,10 +1136,12 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
struct page *page, void *fsdata)
{
struct inode *inode = file->f_dentry->d_inode;
+ struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_mds_client *mdsc = fsc->mdsc;
unsigned from = pos & (PAGE_CACHE_SIZE - 1);
int check_cap = 0;
+ int got = (unsigned long)fsdata;
dout("write_end file %p inode %p page %p %d~%d (%d)\n", file,
inode, page, (int)pos, (int)copied, (int)len);
@@ -1134,6 +1164,19 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
up_read(&mdsc->snap_rwsem);
page_cache_release(page);
+ if (copied > 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("write_end %p %llx.%llx %llu~%u dropping cap refs on %s\n",
+ inode, ceph_vinop(inode), pos, len, ceph_cap_string(got));
+ ceph_put_cap_refs(ci, got);
+
if (check_cap)
ceph_check_caps(ceph_inode(inode), CHECK_CAPS_AUTHONLY, NULL);
diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 5840d2aaed1..d415096800a 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -712,63 +712,53 @@ static ssize_t ceph_aio_write(struct kiocb *iocb, const struct iovec *iov,
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;
+ int got = 0;
+ int ret, err, written;
if (ceph_snap(inode) != CEPH_NOSNAP)
return -EROFS;
retry_snap:
+ written = 0;
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_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 {
- /*
- * buffered write; drop Fw early to avoid slow
- * revocation if we get stuck on balance_dirty_pages
- */
- int dirty;
-
- spin_lock(&ci->i_ceph_lock);
- dirty = __ceph_mark_dirty_caps(ci, CEPH_CAP_FILE_WR);
- spin_unlock(&ci->i_ceph_lock);
- ceph_put_cap_refs(ci, got);
+ /*
+ * try to do a buffered write. if we don't have sufficient
+ * caps, we'll get -EAGAIN from generic_file_aio_write, or a
+ * short write if we only get caps for some pages.
+ */
+ if (!(iocb->ki_filp->f_flags & O_DIRECT) &&
+ !(inode->i_sb->s_flags & MS_SYNCHRONOUS) &&
+ !(fi->flags & CEPH_F_SYNC)) {
ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+ if (ret >= 0)
+ written = ret;
+
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);
+ err = vfs_fsync_range(file, pos, pos + written - 1, 1);
if (err < 0)
ret = err;
}
+ if ((ret < 0 && ret != -EAGAIN) || pos + written >= endoff)
+ goto out;
+ }
- if (dirty)
- __mark_inode_dirty(inode, dirty);
+ dout("aio_write %p %llx.%llx %llu~%u getting caps. i_size %llu\n",
+ inode, ceph_vinop(inode), pos + written,
+ (unsigned)iov->iov_len - written, inode->i_size);
+ ret = ceph_get_caps(ci, CEPH_CAP_FILE_WR, 0, &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 + written,
+ (unsigned)iov->iov_len - written, ceph_cap_string(got));
+ ret = ceph_sync_write(file, iov->iov_base + written,
+ iov->iov_len - written, &iocb->ki_pos);
if (ret >= 0) {
int dirty;
spin_lock(&ci->i_ceph_lock);
@@ -777,13 +767,10 @@ retry_snap:
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));
+ inode, ceph_vinop(inode), pos + written,
+ (unsigned)iov->iov_len - written, ceph_cap_string(got));
ceph_put_cap_refs(ci, got);
-
out:
if (ret == -EOLDSNAPC) {
dout("aio_write %p %llx.%llx %llu~%u got EOLDSNAPC, retrying\n",