From 26544c623e741ac6445f8b1ae369ee32ae1794ad Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Tue, 4 Apr 2017 08:39:46 -0400 Subject: [PATCH] ceph: when seeing write errors on an inode, switch to sync writes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Currently, we don't have a real feedback mechanism in place for when we start seeing buffered writeback errors. If writeback is failing, there is nothing that prevents an application from continuing to dirty pages that aren't being cleaned. In the event that we're seeing write errors of any sort occur on an inode, have the callback set a flag to force further writes to be synchronous. When the next write succeeds, clear the flag to allow buffered writeback to continue. Since this is just a hint to the write submission mechanism, we only take the i_ceph_lock when a lockless check shows that the flag needs to be changed. Signed-off-by: Jeff Layton Reviewed-by: "Yan, Zheng” Signed-off-by: Ilya Dryomov --- fs/ceph/addr.c | 6 +++++- fs/ceph/file.c | 31 ++++++++++++++++++------------- fs/ceph/super.h | 26 ++++++++++++++++++++++++++ 3 files changed, 49 insertions(+), 14 deletions(-) diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 6cdf94459ac4..e253102b43cd 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -670,8 +670,12 @@ static void writepages_finish(struct ceph_osd_request *req) bool remove_page; dout("writepages_finish %p rc %d\n", inode, rc); - if (rc < 0) + if (rc < 0) { mapping_set_error(mapping, rc); + ceph_set_error_write(ci); + } else { + ceph_clear_error_write(ci); + } /* * We lost the cache cap, need to truncate the page before diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 134c978141d0..39866d6a34b6 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -1089,19 +1089,22 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos, 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 + if (ret != 0) { + ceph_set_error_write(ci); break; + } + + ceph_clear_error_write(ci); + 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); + } + } if (ret != -EOLDSNAPC && written > 0) { @@ -1307,6 +1310,7 @@ static ssize_t ceph_write_iter(struct kiocb *iocb, struct iov_iter *from) } retry_snap: + /* FIXME: not complete since it doesn't account for being at quota */ if (ceph_osdmap_flag(osdc, CEPH_OSDMAP_FULL)) { err = -ENOSPC; goto out; @@ -1328,7 +1332,8 @@ retry_snap: inode, ceph_vinop(inode), pos, count, ceph_cap_string(got)); if ((got & (CEPH_CAP_FILE_BUFFER|CEPH_CAP_FILE_LAZYIO)) == 0 || - (iocb->ki_flags & IOCB_DIRECT) || (fi->flags & CEPH_F_SYNC)) { + (iocb->ki_flags & IOCB_DIRECT) || (fi->flags & CEPH_F_SYNC) || + (ci->i_ceph_flags & CEPH_I_ERROR_WRITE)) { struct ceph_snap_context *snapc; struct iov_iter data; inode_unlock(inode); diff --git a/fs/ceph/super.h b/fs/ceph/super.h index c68e6a045fb9..7334ee86b9e8 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -474,6 +474,32 @@ static inline struct inode *ceph_find_inode(struct super_block *sb, #define CEPH_I_CAP_DROPPED (1 << 8) /* caps were forcibly dropped */ #define CEPH_I_KICK_FLUSH (1 << 9) /* kick flushing caps */ #define CEPH_I_FLUSH_SNAPS (1 << 10) /* need flush snapss */ +#define CEPH_I_ERROR_WRITE (1 << 11) /* have seen write errors */ + +/* + * We set the ERROR_WRITE bit when we start seeing write errors on an inode + * and then clear it when they start succeeding. Note that we do a lockless + * check first, and only take the lock if it looks like it needs to be changed. + * The write submission code just takes this as a hint, so we're not too + * worried if a few slip through in either direction. + */ +static inline void ceph_set_error_write(struct ceph_inode_info *ci) +{ + if (!(READ_ONCE(ci->i_ceph_flags) & CEPH_I_ERROR_WRITE)) { + spin_lock(&ci->i_ceph_lock); + ci->i_ceph_flags |= CEPH_I_ERROR_WRITE; + spin_unlock(&ci->i_ceph_lock); + } +} + +static inline void ceph_clear_error_write(struct ceph_inode_info *ci) +{ + if (READ_ONCE(ci->i_ceph_flags) & CEPH_I_ERROR_WRITE) { + spin_lock(&ci->i_ceph_lock); + ci->i_ceph_flags &= ~CEPH_I_ERROR_WRITE; + spin_unlock(&ci->i_ceph_lock); + } +} static inline void __ceph_dir_set_complete(struct ceph_inode_info *ci, long long release_count, -- 2.20.1