diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-16 16:32:04 +0900 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-06-16 16:32:04 +0900 |
commit | 35773c93817c5f2df264d013978e7551056a063a (patch) | |
tree | 5ca02a3f3c680091d5b1019b27ba23b5323a038a /fs/afs/dynroot.c | |
parent | 29d6849d88b61edf130aef500acad78206bda3cd (diff) | |
parent | 47ea0f2ebffd400d36ab5946ec8d6d6e08a67d53 (diff) |
Merge branch 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull AFS updates from Al Viro:
"Assorted AFS stuff - ended up in vfs.git since most of that consists
of David's AFS-related followups to Christoph's procfs series"
* 'afs-proc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
afs: Optimise callback breaking by not repeating volume lookup
afs: Display manually added cells in dynamic root mount
afs: Enable IPv6 DNS lookups
afs: Show all of a server's addresses in /proc/fs/afs/servers
afs: Handle CONFIG_PROC_FS=n
proc: Make inline name size calculation automatic
afs: Implement network namespacing
afs: Mark afs_net::ws_cell as __rcu and set using rcu functions
afs: Fix a Sparse warning in xdr_decode_AFSFetchStatus()
proc: Add a way to make network proc files writable
afs: Rearrange fs/afs/proc.c to remove remaining predeclarations.
afs: Rearrange fs/afs/proc.c to move the show routines up
afs: Rearrange fs/afs/proc.c by moving fops and open functions down
afs: Move /proc management functions to the end of the file
Diffstat (limited to 'fs/afs/dynroot.c')
-rw-r--r-- | fs/afs/dynroot.c | 126 |
1 files changed, 124 insertions, 2 deletions
diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c index 983f3946ab57..174e843f0633 100644 --- a/fs/afs/dynroot.c +++ b/fs/afs/dynroot.c @@ -1,4 +1,4 @@ -/* dir.c: AFS dynamic root handling +/* AFS dynamic root handling * * Copyright (C) 2018 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) @@ -46,7 +46,7 @@ static int afs_probe_cell_name(struct dentry *dentry) return 0; } - ret = dns_query("afsdb", name, len, "ipv4", NULL, NULL); + ret = dns_query("afsdb", name, len, "", NULL, NULL); if (ret == -ENODATA) ret = -EDESTADDRREQ; return ret; @@ -207,3 +207,125 @@ const struct dentry_operations afs_dynroot_dentry_operations = { .d_release = afs_d_release, .d_automount = afs_d_automount, }; + +/* + * Create a manually added cell mount directory. + * - The caller must hold net->proc_cells_lock + */ +int afs_dynroot_mkdir(struct afs_net *net, struct afs_cell *cell) +{ + struct super_block *sb = net->dynroot_sb; + struct dentry *root, *subdir; + int ret; + + if (!sb || atomic_read(&sb->s_active) == 0) + return 0; + + /* Let the ->lookup op do the creation */ + root = sb->s_root; + inode_lock(root->d_inode); + subdir = lookup_one_len(cell->name, root, cell->name_len); + if (IS_ERR(subdir)) { + ret = PTR_ERR(subdir); + goto unlock; + } + + /* Note that we're retaining an extra ref on the dentry */ + subdir->d_fsdata = (void *)1UL; + ret = 0; +unlock: + inode_unlock(root->d_inode); + return ret; +} + +/* + * Remove a manually added cell mount directory. + * - The caller must hold net->proc_cells_lock + */ +void afs_dynroot_rmdir(struct afs_net *net, struct afs_cell *cell) +{ + struct super_block *sb = net->dynroot_sb; + struct dentry *root, *subdir; + + if (!sb || atomic_read(&sb->s_active) == 0) + return; + + root = sb->s_root; + inode_lock(root->d_inode); + + /* Don't want to trigger a lookup call, which will re-add the cell */ + subdir = try_lookup_one_len(cell->name, root, cell->name_len); + if (IS_ERR_OR_NULL(subdir)) { + _debug("lookup %ld", PTR_ERR(subdir)); + goto no_dentry; + } + + _debug("rmdir %pd %u", subdir, d_count(subdir)); + + if (subdir->d_fsdata) { + _debug("unpin %u", d_count(subdir)); + subdir->d_fsdata = NULL; + dput(subdir); + } + dput(subdir); +no_dentry: + inode_unlock(root->d_inode); + _leave(""); +} + +/* + * Populate a newly created dynamic root with cell names. + */ +int afs_dynroot_populate(struct super_block *sb) +{ + struct afs_cell *cell; + struct afs_net *net = afs_sb2net(sb); + int ret; + + if (mutex_lock_interruptible(&net->proc_cells_lock) < 0) + return -ERESTARTSYS; + + net->dynroot_sb = sb; + list_for_each_entry(cell, &net->proc_cells, proc_link) { + ret = afs_dynroot_mkdir(net, cell); + if (ret < 0) + goto error; + } + + ret = 0; +out: + mutex_unlock(&net->proc_cells_lock); + return ret; + +error: + net->dynroot_sb = NULL; + goto out; +} + +/* + * When a dynamic root that's in the process of being destroyed, depopulate it + * of pinned directories. + */ +void afs_dynroot_depopulate(struct super_block *sb) +{ + struct afs_net *net = afs_sb2net(sb); + struct dentry *root = sb->s_root, *subdir, *tmp; + + /* Prevent more subdirs from being created */ + mutex_lock(&net->proc_cells_lock); + if (net->dynroot_sb == sb) + net->dynroot_sb = NULL; + mutex_unlock(&net->proc_cells_lock); + + inode_lock(root->d_inode); + + /* Remove all the pins for dirs created for manually added cells */ + list_for_each_entry_safe(subdir, tmp, &root->d_subdirs, d_child) { + if (subdir->d_fsdata) { + subdir->d_fsdata = NULL; + dput(subdir); + } + } + + inode_unlock(root->d_inode); +} |