diff options
author | David Howells <dhowells@redhat.com> | 2018-11-04 09:28:36 -0500 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-01-30 17:44:26 -0500 |
commit | 8d0347f6c3a9d4953ddd636a31c6584da082e084 (patch) | |
tree | a8dec0e9d854bad8732ae41084e6f7c980713758 /fs/fs_context.c | |
parent | c9ce29ed795fae86e594844857fad1b0d3be85f4 (diff) |
convert do_remount_sb() to fs_context
Replace do_remount_sb() with a function, reconfigure_super(), that's
fs_context aware. The fs_context is expected to be parameterised already
and have ->root pointing to the superblock to be reconfigured.
A legacy wrapper is provided that is intended to be called from the
fs_context ops when those appear, but for now is called directly from
reconfigure_super(). This wrapper invokes the ->remount_fs() superblock op
for the moment. It is intended that the remount_fs() op will be phased
out.
The fs_context->purpose is set to FS_CONTEXT_FOR_RECONFIGURE to indicate
that the context is being used for reconfiguration.
do_umount_root() is provided to consolidate remount-to-R/O for umount and
emergency remount by creating a context and invoking reconfiguration.
do_remount(), do_umount() and do_emergency_remount_callback() are switched
to use the new process.
[AV -- fold UMOUNT and EMERGENCY_REMOUNT in; fixes the
umount / bug, gets rid of pointless complexity]
[AV -- set ->net_ns in all cases; nfs remount will need that]
[AV -- shift security_sb_remount() call into reconfigure_super(); the callers
that didn't do security_sb_remount() have NULL fc->security anyway, so it's
a no-op for them]
Signed-off-by: David Howells <dhowells@redhat.com>
Co-developed-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/fs_context.c')
-rw-r--r-- | fs/fs_context.c | 35 |
1 files changed, 33 insertions, 2 deletions
diff --git a/fs/fs_context.c b/fs/fs_context.c index 857cd46a687b..5e2c3aba1dd8 100644 --- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -69,6 +69,13 @@ static struct fs_context *alloc_fs_context(struct file_system_type *fs_type, case FS_CONTEXT_FOR_MOUNT: fc->user_ns = get_user_ns(fc->cred->user_ns); break; + case FS_CONTEXT_FOR_RECONFIGURE: + /* We don't pin any namespaces as the superblock's + * subscriptions cannot be changed at this point. + */ + atomic_inc(&reference->d_sb->s_active); + fc->root = dget(reference); + break; } ret = legacy_init_fs_context(fc); @@ -90,6 +97,15 @@ struct fs_context *fs_context_for_mount(struct file_system_type *fs_type, } EXPORT_SYMBOL(fs_context_for_mount); +struct fs_context *fs_context_for_reconfigure(struct dentry *dentry, + unsigned int sb_flags, + unsigned int sb_flags_mask) +{ + return alloc_fs_context(dentry->d_sb->s_type, dentry, sb_flags, + sb_flags_mask, FS_CONTEXT_FOR_RECONFIGURE); +} +EXPORT_SYMBOL(fs_context_for_reconfigure); + void fc_drop_locked(struct fs_context *fc) { struct super_block *sb = fc->root->d_sb; @@ -99,6 +115,7 @@ void fc_drop_locked(struct fs_context *fc) } static void legacy_fs_context_free(struct fs_context *fc); + /** * put_fs_context - Dispose of a superblock configuration context. * @fc: The context to dispose of. @@ -118,8 +135,7 @@ void put_fs_context(struct fs_context *fc) legacy_fs_context_free(fc); security_free_mnt_opts(&fc->security); - if (fc->net_ns) - put_net(fc->net_ns); + put_net(fc->net_ns); put_user_ns(fc->user_ns); put_cred(fc->cred); kfree(fc->subtype); @@ -173,6 +189,21 @@ int legacy_get_tree(struct fs_context *fc) } /* + * Handle remount. + */ +int legacy_reconfigure(struct fs_context *fc) +{ + struct legacy_fs_context *ctx = fc->fs_private; + struct super_block *sb = fc->root->d_sb; + + if (!sb->s_op->remount_fs) + return 0; + + return sb->s_op->remount_fs(sb, &fc->sb_flags, + ctx ? ctx->legacy_data : NULL); +} + +/* * Initialise a legacy context for a filesystem that doesn't support * fs_context. */ |