From 863981e96738983919de841ec669e157e6bdaeb0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Sun, 11 Sep 2016 04:34:46 -0300 Subject: Linux-libre 4.7.1-gnu --- fs/nfs/unlink.c | 192 +++++++++++++++----------------------------------------- 1 file changed, 51 insertions(+), 141 deletions(-) (limited to 'fs/nfs/unlink.c') diff --git a/fs/nfs/unlink.c b/fs/nfs/unlink.c index fa538b2ba..1868246f5 100644 --- a/fs/nfs/unlink.c +++ b/fs/nfs/unlink.c @@ -30,45 +30,11 @@ static void nfs_free_unlinkdata(struct nfs_unlinkdata *data) { - iput(data->dir); put_rpccred(data->cred); kfree(data->args.name.name); kfree(data); } -#define NAME_ALLOC_LEN(len) ((len+16) & ~15) -/** - * nfs_copy_dname - copy dentry name to data structure - * @dentry: pointer to dentry - * @data: nfs_unlinkdata - */ -static int nfs_copy_dname(struct dentry *dentry, struct nfs_unlinkdata *data) -{ - char *str; - int len = dentry->d_name.len; - - str = kmemdup(dentry->d_name.name, NAME_ALLOC_LEN(len), GFP_KERNEL); - if (!str) - return -ENOMEM; - data->args.name.len = len; - data->args.name.name = str; - return 0; -} - -static void nfs_free_dname(struct nfs_unlinkdata *data) -{ - kfree(data->args.name.name); - data->args.name.name = NULL; - data->args.name.len = 0; -} - -static void nfs_dec_sillycount(struct inode *dir) -{ - struct nfs_inode *nfsi = NFS_I(dir); - if (atomic_dec_return(&nfsi->silly_count) == 1) - wake_up(&nfsi->waitqueue); -} - /** * nfs_async_unlink_done - Sillydelete post-processing * @task: rpc_task of the sillydelete @@ -78,7 +44,7 @@ static void nfs_dec_sillycount(struct inode *dir) static void nfs_async_unlink_done(struct rpc_task *task, void *calldata) { struct nfs_unlinkdata *data = calldata; - struct inode *dir = data->dir; + struct inode *dir = d_inode(data->dentry->d_parent); trace_nfs_sillyrename_unlink(data, task->tk_status); if (!NFS_PROTO(dir)->unlink_done(task, dir)) @@ -95,17 +61,21 @@ static void nfs_async_unlink_done(struct rpc_task *task, void *calldata) static void nfs_async_unlink_release(void *calldata) { struct nfs_unlinkdata *data = calldata; - struct super_block *sb = data->dir->i_sb; + struct dentry *dentry = data->dentry; + struct super_block *sb = dentry->d_sb; - nfs_dec_sillycount(data->dir); + up_read_non_owner(&NFS_I(d_inode(dentry->d_parent))->rmdir_sem); + d_lookup_done(dentry); nfs_free_unlinkdata(data); + dput(dentry); nfs_sb_deactive(sb); } static void nfs_unlink_prepare(struct rpc_task *task, void *calldata) { struct nfs_unlinkdata *data = calldata; - NFS_PROTO(data->dir)->unlink_rpc_prepare(task, data); + struct inode *dir = d_inode(data->dentry->d_parent); + NFS_PROTO(dir)->unlink_rpc_prepare(task, data); } static const struct rpc_call_ops nfs_unlink_ops = { @@ -114,7 +84,7 @@ static const struct rpc_call_ops nfs_unlink_ops = { .rpc_call_prepare = nfs_unlink_prepare, }; -static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct nfs_unlinkdata *data) +static void nfs_do_call_unlink(struct nfs_unlinkdata *data) { struct rpc_message msg = { .rpc_argp = &data->args, @@ -129,10 +99,31 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n .flags = RPC_TASK_ASYNC, }; struct rpc_task *task; + struct inode *dir = d_inode(data->dentry->d_parent); + nfs_sb_active(dir->i_sb); + data->args.fh = NFS_FH(dir); + nfs_fattr_init(data->res.dir_attr); + + NFS_PROTO(dir)->unlink_setup(&msg, dir); + + task_setup_data.rpc_client = NFS_CLIENT(dir); + task = rpc_run_task(&task_setup_data); + if (!IS_ERR(task)) + rpc_put_task_async(task); +} + +static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data) +{ + struct inode *dir = d_inode(dentry->d_parent); struct dentry *alias; - alias = d_lookup(parent, &data->args.name); - if (alias != NULL) { + down_read_non_owner(&NFS_I(dir)->rmdir_sem); + alias = d_alloc_parallel(dentry->d_parent, &data->args.name, &data->wq); + if (IS_ERR(alias)) { + up_read_non_owner(&NFS_I(dir)->rmdir_sem); + return 0; + } + if (!d_in_lookup(alias)) { int ret; void *devname_garbage = NULL; @@ -140,10 +131,8 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n * Hey, we raced with lookup... See if we need to transfer * the sillyrename information to the aliased dentry. */ - nfs_free_dname(data); - ret = nfs_copy_dname(alias, data); spin_lock(&alias->d_lock); - if (ret == 0 && d_really_is_positive(alias) && + if (d_really_is_positive(alias) && !(alias->d_flags & DCACHE_NFSFS_RENAMED)) { devname_garbage = alias->d_fsdata; alias->d_fsdata = data; @@ -152,8 +141,8 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n } else ret = 0; spin_unlock(&alias->d_lock); - nfs_dec_sillycount(dir); dput(alias); + up_read_non_owner(&NFS_I(dir)->rmdir_sem); /* * If we'd displaced old cached devname, free it. At that * point dentry is definitely not a root, so we won't need @@ -162,94 +151,18 @@ static int nfs_do_call_unlink(struct dentry *parent, struct inode *dir, struct n kfree(devname_garbage); return ret; } - data->dir = igrab(dir); - if (!data->dir) { - nfs_dec_sillycount(dir); - return 0; - } - nfs_sb_active(dir->i_sb); - data->args.fh = NFS_FH(dir); - nfs_fattr_init(data->res.dir_attr); - - NFS_PROTO(dir)->unlink_setup(&msg, dir); - - task_setup_data.rpc_client = NFS_CLIENT(dir); - task = rpc_run_task(&task_setup_data); - if (!IS_ERR(task)) - rpc_put_task_async(task); + data->dentry = alias; + nfs_do_call_unlink(data); return 1; } -static int nfs_call_unlink(struct dentry *dentry, struct nfs_unlinkdata *data) -{ - struct dentry *parent; - struct inode *dir; - int ret = 0; - - - parent = dget_parent(dentry); - if (parent == NULL) - goto out_free; - dir = d_inode(parent); - /* Non-exclusive lock protects against concurrent lookup() calls */ - spin_lock(&dir->i_lock); - if (atomic_inc_not_zero(&NFS_I(dir)->silly_count) == 0) { - /* Deferred delete */ - hlist_add_head(&data->list, &NFS_I(dir)->silly_list); - spin_unlock(&dir->i_lock); - ret = 1; - goto out_dput; - } - spin_unlock(&dir->i_lock); - ret = nfs_do_call_unlink(parent, dir, data); -out_dput: - dput(parent); -out_free: - return ret; -} - -void nfs_wait_on_sillyrename(struct dentry *dentry) -{ - struct nfs_inode *nfsi = NFS_I(d_inode(dentry)); - - wait_event(nfsi->waitqueue, atomic_read(&nfsi->silly_count) <= 1); -} - -void nfs_block_sillyrename(struct dentry *dentry) -{ - struct nfs_inode *nfsi = NFS_I(d_inode(dentry)); - - wait_event(nfsi->waitqueue, atomic_cmpxchg(&nfsi->silly_count, 1, 0) == 1); -} - -void nfs_unblock_sillyrename(struct dentry *dentry) -{ - struct inode *dir = d_inode(dentry); - struct nfs_inode *nfsi = NFS_I(dir); - struct nfs_unlinkdata *data; - - atomic_inc(&nfsi->silly_count); - spin_lock(&dir->i_lock); - while (!hlist_empty(&nfsi->silly_list)) { - if (!atomic_inc_not_zero(&nfsi->silly_count)) - break; - data = hlist_entry(nfsi->silly_list.first, struct nfs_unlinkdata, list); - hlist_del(&data->list); - spin_unlock(&dir->i_lock); - if (nfs_do_call_unlink(dentry, dir, data) == 0) - nfs_free_unlinkdata(data); - spin_lock(&dir->i_lock); - } - spin_unlock(&dir->i_lock); -} - /** * nfs_async_unlink - asynchronous unlinking of a file * @dir: parent directory of dentry * @dentry: dentry to unlink */ static int -nfs_async_unlink(struct inode *dir, struct dentry *dentry) +nfs_async_unlink(struct dentry *dentry, struct qstr *name) { struct nfs_unlinkdata *data; int status = -ENOMEM; @@ -258,13 +171,18 @@ nfs_async_unlink(struct inode *dir, struct dentry *dentry) data = kzalloc(sizeof(*data), GFP_KERNEL); if (data == NULL) goto out; + data->args.name.name = kstrdup(name->name, GFP_KERNEL); + if (!data->args.name.name) + goto out_free; + data->args.name.len = name->len; data->cred = rpc_lookup_cred(); if (IS_ERR(data->cred)) { status = PTR_ERR(data->cred); - goto out_free; + goto out_free_name; } data->res.dir_attr = &data->dir_attr; + init_waitqueue_head(&data->wq); status = -EBUSY; spin_lock(&dentry->d_lock); @@ -284,6 +202,8 @@ nfs_async_unlink(struct inode *dir, struct dentry *dentry) out_unlock: spin_unlock(&dentry->d_lock); put_rpccred(data->cred); +out_free_name: + kfree(data->args.name.name); out_free: kfree(data); out: @@ -302,17 +222,15 @@ out: void nfs_complete_unlink(struct dentry *dentry, struct inode *inode) { - struct nfs_unlinkdata *data = NULL; + struct nfs_unlinkdata *data; spin_lock(&dentry->d_lock); - if (dentry->d_flags & DCACHE_NFSFS_RENAMED) { - dentry->d_flags &= ~DCACHE_NFSFS_RENAMED; - data = dentry->d_fsdata; - dentry->d_fsdata = NULL; - } + dentry->d_flags &= ~DCACHE_NFSFS_RENAMED; + data = dentry->d_fsdata; + dentry->d_fsdata = NULL; spin_unlock(&dentry->d_lock); - if (data != NULL && (NFS_STALE(inode) || !nfs_call_unlink(dentry, data))) + if (NFS_STALE(inode) || !nfs_call_unlink(dentry, data)) nfs_free_unlinkdata(data); } @@ -559,18 +477,10 @@ nfs_sillyrename(struct inode *dir, struct dentry *dentry) /* queue unlink first. Can't do this from rpc_release as it * has to allocate memory */ - error = nfs_async_unlink(dir, dentry); + error = nfs_async_unlink(dentry, &sdentry->d_name); if (error) goto out_dput; - /* populate unlinkdata with the right dname */ - error = nfs_copy_dname(sdentry, - (struct nfs_unlinkdata *)dentry->d_fsdata); - if (error) { - nfs_cancel_async_unlink(dentry); - goto out_dput; - } - /* run the rename task, undo unlink if it fails */ task = nfs_async_rename(dir, dir, dentry, sdentry, nfs_complete_sillyrename); -- cgit v1.2.3-54-g00ecf