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authorDavid Howells <dhowells@redhat.com>2019-04-25 14:26:52 +0100
committerDavid Howells <dhowells@redhat.com>2019-04-25 14:26:52 +0100
commit6c6c1d63c243025956f061e67fff3a615aa0f6be (patch)
tree2dc16f2dfa389efcc4b53197a33a9654cf02f794 /fs/afs/super.c
parent80548b03991f58758a336424a90bf9f988e3b077 (diff)
afs: Provide mount-time configurable byte-range file locking emulation
Provide byte-range file locking emulation that can be configured at mount time to one of four modes: (1) flock=local. Locking is done locally only and no reference is made to the server. (2) flock=openafs. Byte-range locking is done locally only; whole-file locking is done with reference to the server. Whole-file locks cannot be upgraded unless the client holds an exclusive lock. (3) flock=strict. Byte-range and whole-file locking both require a sufficient whole-file lock on the server. (4) flock=write. As strict, but the client always gets an exclusive whole-file lock on the server. Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'fs/afs/super.c')
-rw-r--r--fs/afs/super.c27
1 files changed, 27 insertions, 0 deletions
diff --git a/fs/afs/super.c b/fs/afs/super.c
index ce85ae61f12d..18334fa1a0d2 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -67,19 +67,30 @@ static atomic_t afs_count_active_inodes;
enum afs_param {
Opt_autocell,
Opt_dyn,
+ Opt_flock,
Opt_source,
};
static const struct fs_parameter_spec afs_param_specs[] = {
fsparam_flag ("autocell", Opt_autocell),
fsparam_flag ("dyn", Opt_dyn),
+ fsparam_enum ("flock", Opt_flock),
fsparam_string("source", Opt_source),
{}
};
+static const struct fs_parameter_enum afs_param_enums[] = {
+ { Opt_flock, "local", afs_flock_mode_local },
+ { Opt_flock, "openafs", afs_flock_mode_openafs },
+ { Opt_flock, "strict", afs_flock_mode_strict },
+ { Opt_flock, "write", afs_flock_mode_write },
+ {}
+};
+
static const struct fs_parameter_description afs_fs_parameters = {
.name = "kAFS",
.specs = afs_param_specs,
+ .enums = afs_param_enums,
};
/*
@@ -182,11 +193,22 @@ static int afs_show_devname(struct seq_file *m, struct dentry *root)
static int afs_show_options(struct seq_file *m, struct dentry *root)
{
struct afs_super_info *as = AFS_FS_S(root->d_sb);
+ const char *p = NULL;
if (as->dyn_root)
seq_puts(m, ",dyn");
if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
seq_puts(m, ",autocell");
+ switch (as->flock_mode) {
+ case afs_flock_mode_unset: break;
+ case afs_flock_mode_local: p = "local"; break;
+ case afs_flock_mode_openafs: p = "openafs"; break;
+ case afs_flock_mode_strict: p = "strict"; break;
+ case afs_flock_mode_write: p = "write"; break;
+ }
+ if (p)
+ seq_printf(m, ",flock=%s", p);
+
return 0;
}
@@ -315,6 +337,10 @@ static int afs_parse_param(struct fs_context *fc, struct fs_parameter *param)
ctx->dyn_root = true;
break;
+ case Opt_flock:
+ ctx->flock_mode = result.uint_32;
+ break;
+
default:
return -EINVAL;
}
@@ -466,6 +492,7 @@ static struct afs_super_info *afs_alloc_sbi(struct fs_context *fc)
as = kzalloc(sizeof(struct afs_super_info), GFP_KERNEL);
if (as) {
as->net_ns = get_net(fc->net_ns);
+ as->flock_mode = ctx->flock_mode;
if (ctx->dyn_root) {
as->dyn_root = true;
} else {