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author | Yan, Zheng <zyan@redhat.com> | 2015-01-09 15:56:18 +0800 |
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committer | Ilya Dryomov <idryomov@gmail.com> | 2015-02-19 13:31:38 +0300 |
commit | c4d4a582c538e890f09c338bc3063c28dfdc9ae5 (patch) | |
tree | 2d6d7d75b857efcda89931866481057660dedaae /fs/ceph/caps.c | |
parent | d3383a8e37f802818cde4cb489bb0735db637cf0 (diff) | |
download | lwn-c4d4a582c538e890f09c338bc3063c28dfdc9ae5.tar.gz lwn-c4d4a582c538e890f09c338bc3063c28dfdc9ae5.zip |
ceph: avoid block operation when !TASK_RUNNING (ceph_get_caps)
we should not do block operation in wait_event_interruptible()'s condition
check function, but reading inline data can block. so move the read inline
data code to ceph_get_caps()
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Diffstat (limited to 'fs/ceph/caps.c')
-rw-r--r-- | fs/ceph/caps.c | 86 |
1 files changed, 42 insertions, 44 deletions
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 844b57cb52bd..8172775428a0 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -2072,17 +2072,16 @@ static void __take_cap_refs(struct ceph_inode_info *ci, int got) * requested from the MDS. */ static int try_get_cap_refs(struct ceph_inode_info *ci, int need, int want, - loff_t endoff, int *got, struct page **pinned_page, - int *check_max, int *err) + loff_t endoff, int *got, int *check_max, int *err) { struct inode *inode = &ci->vfs_inode; int ret = 0; - int have, implemented, _got = 0; + int have, implemented; int file_wanted; dout("get_cap_refs %p need %s want %s\n", inode, ceph_cap_string(need), ceph_cap_string(want)); -again: + spin_lock(&ci->i_ceph_lock); /* make sure file is actually open */ @@ -2137,8 +2136,8 @@ again: inode, ceph_cap_string(have), ceph_cap_string(not), ceph_cap_string(revoking)); if ((revoking & not) == 0) { - _got = need | (have & want); - __take_cap_refs(ci, _got); + *got = need | (have & want); + __take_cap_refs(ci, *got); ret = 1; } } else { @@ -2163,39 +2162,8 @@ again: out_unlock: spin_unlock(&ci->i_ceph_lock); - if (ci->i_inline_version != CEPH_INLINE_NONE && - (_got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) && - i_size_read(inode) > 0) { - int ret1; - struct page *page = find_get_page(inode->i_mapping, 0); - if (page) { - if (PageUptodate(page)) { - *pinned_page = page; - goto out; - } - page_cache_release(page); - } - /* - * drop cap refs first because getattr while holding - * caps refs can cause deadlock. - */ - ceph_put_cap_refs(ci, _got); - _got = 0; - - /* getattr request will bring inline data into page cache */ - ret1 = __ceph_do_getattr(inode, NULL, - CEPH_STAT_CAP_INLINE_DATA, true); - if (ret1 >= 0) { - ret = 0; - goto again; - } - *err = ret1; - ret = 1; - } -out: dout("get_cap_refs %p ret %d got %s\n", inode, - ret, ceph_cap_string(_got)); - *got = _got; + ret, ceph_cap_string(*got)); return ret; } @@ -2235,22 +2203,52 @@ static void check_max_size(struct inode *inode, loff_t endoff) int ceph_get_caps(struct ceph_inode_info *ci, int need, int want, loff_t endoff, int *got, struct page **pinned_page) { - int check_max, ret, err; + int _got, check_max, ret, err = 0; retry: if (endoff > 0) check_max_size(&ci->vfs_inode, endoff); + _got = 0; check_max = 0; - err = 0; ret = wait_event_interruptible(ci->i_cap_wq, - try_get_cap_refs(ci, need, want, endoff, - got, pinned_page, - &check_max, &err)); + try_get_cap_refs(ci, need, want, endoff, + &_got, &check_max, &err)); if (err) ret = err; + if (ret < 0) + return ret; + if (check_max) goto retry; - return ret; + + if (ci->i_inline_version != CEPH_INLINE_NONE && + (_got & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) && + i_size_read(&ci->vfs_inode) > 0) { + struct page *page = find_get_page(ci->vfs_inode.i_mapping, 0); + if (page) { + if (PageUptodate(page)) { + *pinned_page = page; + goto out; + } + page_cache_release(page); + } + /* + * drop cap refs first because getattr while holding + * caps refs can cause deadlock. + */ + ceph_put_cap_refs(ci, _got); + _got = 0; + + /* getattr request will bring inline data into page cache */ + ret = __ceph_do_getattr(&ci->vfs_inode, NULL, + CEPH_STAT_CAP_INLINE_DATA, true); + if (ret < 0) + return ret; + goto retry; + } +out: + *got = _got; + return 0; } /* |