xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

afs: Provide mount-time configurable byte-range file locking emulation

Browse Source 
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>
This commit is contained in:
David Howells
2019-04-25 14:26:52 +01:00
parent 80548b0399
commit 6c6c1d63c2
6 changed files with 120 additions and 9 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
fs/afs/super.c
View File

@@ -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 {