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| author | Al Viro <viro@zeniv.linux.org.uk> | 2015-11-18 05:14:24 +0300 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2015-12-09 06:41:55 +0300 |
| commit | 0d0def49d05ae988936268b0e57d19aeef8c3ad2 (patch) | |
| tree | 471fbf67f67815197aea2540650ee73d754b40ac | |
| parent | 1a384eaac265b57961c9696d9177f82eb84319e9 (diff) | |
| download | linux-0d0def49d05ae988936268b0e57d19aeef8c3ad2.tar.xz | |
teach nfs_get_link() to work in RCU mode
based upon the corresponding patch from Neil's March patchset,
again with kmap-related horrors removed.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/nfs/inode.c | 21 | ||||
| -rw-r--r-- | fs/nfs/symlink.c | 30 | ||||
| -rw-r--r-- | include/linux/nfs_fs.h | 1 |
3 files changed, 42 insertions, 10 deletions
diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index ae9aa0b8155c..aa828e8b6e04 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1087,6 +1087,27 @@ static bool nfs_mapping_need_revalidate_inode(struct inode *inode) || NFS_STALE(inode); } +int nfs_revalidate_mapping_rcu(struct inode *inode) +{ + struct nfs_inode *nfsi = NFS_I(inode); + unsigned long *bitlock = &nfsi->flags; + int ret = 0; + + if (IS_SWAPFILE(inode)) + goto out; + if (nfs_mapping_need_revalidate_inode(inode)) { + ret = -ECHILD; + goto out; + } + spin_lock(&inode->i_lock); + if (test_bit(NFS_INO_INVALIDATING, bitlock) || + (nfsi->cache_validity & NFS_INO_INVALID_DATA)) + ret = -ECHILD; + spin_unlock(&inode->i_lock); +out: + return ret; +} + /** * __nfs_revalidate_mapping - Revalidate the pagecache * @inode - pointer to host inode diff --git a/fs/nfs/symlink.c b/fs/nfs/symlink.c index 8ade8a812607..95c69af7e4d0 100644 --- a/fs/nfs/symlink.c +++ b/fs/nfs/symlink.c @@ -48,16 +48,26 @@ static const char *nfs_get_link(struct dentry *dentry, struct page *page; void *err; - if (!dentry) - return ERR_PTR(-ECHILD); - - err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping)); - if (err) - return err; - page = read_cache_page(&inode->i_data, 0, - (filler_t *)nfs_symlink_filler, inode); - if (IS_ERR(page)) - return ERR_CAST(page); + if (!dentry) { + err = ERR_PTR(nfs_revalidate_mapping_rcu(inode)); + if (err) + return err; + page = find_get_page(inode->i_mapping, 0); + if (!page) + return ERR_PTR(-ECHILD); + if (!PageUptodate(page)) { + put_page(page); + return ERR_PTR(-ECHILD); + } + } else { + err = ERR_PTR(nfs_revalidate_mapping(inode, inode->i_mapping)); + if (err) + return err; + page = read_cache_page(&inode->i_data, 0, + (filler_t *)nfs_symlink_filler, inode); + if (IS_ERR(page)) + return ERR_CAST(page); + } *cookie = page; return page_address(page); } diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index c0e961474a52..37a3d2981352 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -359,6 +359,7 @@ extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode); extern int nfs_revalidate_inode_rcu(struct nfs_server *server, struct inode *inode); extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *); extern int nfs_revalidate_mapping(struct inode *inode, struct address_space *mapping); +extern int nfs_revalidate_mapping_rcu(struct inode *inode); extern int nfs_revalidate_mapping_protected(struct inode *inode, struct address_space *mapping); extern int nfs_setattr(struct dentry *, struct iattr *); extern void nfs_setattr_update_inode(struct inode *inode, struct iattr *attr, struct nfs_fattr *); |