GFS2: Clean up of extended attribute support
This has been on my list for some time. We need to change the way
in which we handle extended attributes to allow faster file creation
times (by reducing the number of transactions required) and the
extended attribute code is the main obstacle to this.
In addition to that, the VFS provides a way to demultiplex the xattr
calls which we ought to be using, rather than rolling our own. This
patch changes the GFS2 code to use that VFS feature and as a result
the code shrinks by a couple of hundred lines or so, and becomes
easier to read.
I'm planning on doing further clean up work in this area, but this
patch is a good start. The cleaned up code also uses the more usual
"xattr" shorthand, I plan to eliminate the use of "eattr" eventually
and in the mean time it serves as a flag as to which bits of the code
have been updated.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/eattr.c b/fs/gfs2/eattr.c
index 07ea952..d9a9e26 100644
--- a/fs/gfs2/eattr.c
+++ b/fs/gfs2/eattr.c
@@ -18,7 +18,6 @@
#include "gfs2.h"
#include "incore.h"
#include "acl.h"
-#include "eaops.h"
#include "eattr.h"
#include "glock.h"
#include "inode.h"
@@ -38,26 +37,32 @@
* Returns: 1 if the EA should be stuffed
*/
-static int ea_calc_size(struct gfs2_sbd *sdp, struct gfs2_ea_request *er,
+static int ea_calc_size(struct gfs2_sbd *sdp, unsigned int nsize, size_t dsize,
unsigned int *size)
{
- *size = GFS2_EAREQ_SIZE_STUFFED(er);
- if (*size <= sdp->sd_jbsize)
+ unsigned int jbsize = sdp->sd_jbsize;
+
+ /* Stuffed */
+ *size = ALIGN(sizeof(struct gfs2_ea_header) + nsize + dsize, 8);
+
+ if (*size <= jbsize)
return 1;
- *size = GFS2_EAREQ_SIZE_UNSTUFFED(sdp, er);
+ /* Unstuffed */
+ *size = ALIGN(sizeof(struct gfs2_ea_header) + nsize +
+ (sizeof(__be64) * DIV_ROUND_UP(dsize, jbsize)), 8);
return 0;
}
-static int ea_check_size(struct gfs2_sbd *sdp, struct gfs2_ea_request *er)
+static int ea_check_size(struct gfs2_sbd *sdp, unsigned int nsize, size_t dsize)
{
unsigned int size;
- if (er->er_data_len > GFS2_EA_MAX_DATA_LEN)
+ if (dsize > GFS2_EA_MAX_DATA_LEN)
return -ERANGE;
- ea_calc_size(sdp, er, &size);
+ ea_calc_size(sdp, nsize, dsize, &size);
/* This can only happen with 512 byte blocks */
if (size > sdp->sd_jbsize)
@@ -151,7 +156,9 @@
}
struct ea_find {
- struct gfs2_ea_request *ef_er;
+ int type;
+ const char *name;
+ size_t namel;
struct gfs2_ea_location *ef_el;
};
@@ -160,14 +167,13 @@
void *private)
{
struct ea_find *ef = private;
- struct gfs2_ea_request *er = ef->ef_er;
if (ea->ea_type == GFS2_EATYPE_UNUSED)
return 0;
- if (ea->ea_type == er->er_type) {
- if (ea->ea_name_len == er->er_name_len &&
- !memcmp(GFS2_EA2NAME(ea), er->er_name, ea->ea_name_len)) {
+ if (ea->ea_type == ef->type) {
+ if (ea->ea_name_len == ef->namel &&
+ !memcmp(GFS2_EA2NAME(ea), ef->name, ea->ea_name_len)) {
struct gfs2_ea_location *el = ef->ef_el;
get_bh(bh);
el->el_bh = bh;
@@ -180,13 +186,15 @@
return 0;
}
-int gfs2_ea_find(struct gfs2_inode *ip, struct gfs2_ea_request *er,
+int gfs2_ea_find(struct gfs2_inode *ip, int type, const char *name,
struct gfs2_ea_location *el)
{
struct ea_find ef;
int error;
- ef.ef_er = er;
+ ef.type = type;
+ ef.name = name;
+ ef.namel = strlen(name);
ef.ef_el = el;
memset(el, 0, sizeof(struct gfs2_ea_location));
@@ -344,6 +352,20 @@
unsigned int ei_size;
};
+static inline unsigned int gfs2_ea_strlen(struct gfs2_ea_header *ea)
+{
+ switch (ea->ea_type) {
+ case GFS2_EATYPE_USR:
+ return 5 + ea->ea_name_len + 1;
+ case GFS2_EATYPE_SYS:
+ return 7 + ea->ea_name_len + 1;
+ case GFS2_EATYPE_SECURITY:
+ return 9 + ea->ea_name_len + 1;
+ default:
+ return 0;
+ }
+}
+
static int ea_list_i(struct gfs2_inode *ip, struct buffer_head *bh,
struct gfs2_ea_header *ea, struct gfs2_ea_header *prev,
void *private)
@@ -392,21 +414,25 @@
}
/**
- * gfs2_ea_list -
- * @ip:
- * @er:
+ * gfs2_listxattr - List gfs2 extended attributes
+ * @dentry: The dentry whose inode we are interested in
+ * @buffer: The buffer to write the results
+ * @size: The size of the buffer
*
* Returns: actual size of data on success, -errno on error
*/
-int gfs2_ea_list(struct gfs2_inode *ip, struct gfs2_ea_request *er)
+ssize_t gfs2_listxattr(struct dentry *dentry, char *buffer, size_t size)
{
+ struct gfs2_inode *ip = GFS2_I(dentry->d_inode);
+ struct gfs2_ea_request er;
struct gfs2_holder i_gh;
int error;
- if (!er->er_data || !er->er_data_len) {
- er->er_data = NULL;
- er->er_data_len = 0;
+ memset(&er, 0, sizeof(struct gfs2_ea_request));
+ if (size) {
+ er.er_data = buffer;
+ er.er_data_len = size;
}
error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
@@ -414,7 +440,7 @@
return error;
if (ip->i_eattr) {
- struct ea_list ei = { .ei_er = er, .ei_size = 0 };
+ struct ea_list ei = { .ei_er = &er, .ei_size = 0 };
error = ea_foreach(ip, ea_list_i, &ei);
if (!error)
@@ -491,84 +517,61 @@
}
int gfs2_ea_get_copy(struct gfs2_inode *ip, struct gfs2_ea_location *el,
- char *data)
+ char *data, size_t size)
{
+ int ret;
+ size_t len = GFS2_EA_DATA_LEN(el->el_ea);
+ if (len > size)
+ return -ERANGE;
+
if (GFS2_EA_IS_STUFFED(el->el_ea)) {
- memcpy(data, GFS2_EA2DATA(el->el_ea), GFS2_EA_DATA_LEN(el->el_ea));
- return 0;
- } else
- return ea_get_unstuffed(ip, el->el_ea, data);
+ memcpy(data, GFS2_EA2DATA(el->el_ea), len);
+ return len;
+ }
+ ret = ea_get_unstuffed(ip, el->el_ea, data);
+ if (ret < 0)
+ return ret;
+ return len;
}
/**
- * gfs2_ea_get_i -
- * @ip: The GFS2 inode
- * @er: The request structure
+ * gfs2_xattr_get - Get a GFS2 extended attribute
+ * @inode: The inode
+ * @type: The type of extended attribute
+ * @name: The name of the extended attribute
+ * @buffer: The buffer to write the result into
+ * @size: The size of the buffer
*
* Returns: actual size of data on success, -errno on error
*/
-int gfs2_ea_get_i(struct gfs2_inode *ip, struct gfs2_ea_request *er)
+int gfs2_xattr_get(struct inode *inode, int type, const char *name,
+ void *buffer, size_t size)
{
+ struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_ea_location el;
int error;
if (!ip->i_eattr)
return -ENODATA;
+ if (strlen(name) > GFS2_EA_MAX_NAME_LEN)
+ return -EINVAL;
- error = gfs2_ea_find(ip, er, &el);
+ error = gfs2_ea_find(ip, type, name, &el);
if (error)
return error;
if (!el.el_ea)
return -ENODATA;
-
- if (er->er_data_len) {
- if (GFS2_EA_DATA_LEN(el.el_ea) > er->er_data_len)
- error = -ERANGE;
- else
- error = gfs2_ea_get_copy(ip, &el, er->er_data);
- }
- if (!error)
+ if (size)
+ error = gfs2_ea_get_copy(ip, &el, buffer, size);
+ else
error = GFS2_EA_DATA_LEN(el.el_ea);
-
brelse(el.el_bh);
return error;
}
/**
- * gfs2_ea_get -
- * @ip: The GFS2 inode
- * @er: The request structure
- *
- * Returns: actual size of data on success, -errno on error
- */
-
-int gfs2_ea_get(struct gfs2_inode *ip, struct gfs2_ea_request *er)
-{
- struct gfs2_holder i_gh;
- int error;
-
- if (!er->er_name_len ||
- er->er_name_len > GFS2_EA_MAX_NAME_LEN)
- return -EINVAL;
- if (!er->er_data || !er->er_data_len) {
- er->er_data = NULL;
- er->er_data_len = 0;
- }
-
- error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh);
- if (error)
- return error;
-
- error = gfs2_ea_ops[er->er_type]->eo_get(ip, er);
-
- gfs2_glock_dq_uninit(&i_gh);
-
- return error;
-}
-
-/**
* ea_alloc_blk - allocates a new block for extended attributes.
* @ip: A pointer to the inode that's getting extended attributes
* @bhp: Pointer to pointer to a struct buffer_head
@@ -713,12 +716,6 @@
error = gfs2_meta_inode_buffer(ip, &dibh);
if (!error) {
- if (er->er_flags & GFS2_ERF_MODE) {
- gfs2_assert_withdraw(GFS2_SB(&ip->i_inode),
- (ip->i_inode.i_mode & S_IFMT) ==
- (er->er_mode & S_IFMT));
- ip->i_inode.i_mode = er->er_mode;
- }
ip->i_inode.i_ctime = CURRENT_TIME;
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(ip, dibh->b_data);
@@ -762,15 +759,23 @@
* Returns: errno
*/
-static int ea_init(struct gfs2_inode *ip, struct gfs2_ea_request *er)
+static int ea_init(struct gfs2_inode *ip, int type, const char *name,
+ const void *data, size_t size)
{
+ struct gfs2_ea_request er;
unsigned int jbsize = GFS2_SB(&ip->i_inode)->sd_jbsize;
unsigned int blks = 1;
- if (GFS2_EAREQ_SIZE_STUFFED(er) > jbsize)
- blks += DIV_ROUND_UP(er->er_data_len, jbsize);
+ er.er_type = type;
+ er.er_name = name;
+ er.er_name_len = strlen(name);
+ er.er_data = (void *)data;
+ er.er_data_len = size;
- return ea_alloc_skeleton(ip, er, blks, ea_init_i, NULL);
+ if (GFS2_EAREQ_SIZE_STUFFED(&er) > jbsize)
+ blks += DIV_ROUND_UP(er.er_data_len, jbsize);
+
+ return ea_alloc_skeleton(ip, &er, blks, ea_init_i, NULL);
}
static struct gfs2_ea_header *ea_split_ea(struct gfs2_ea_header *ea)
@@ -848,12 +853,6 @@
error = gfs2_meta_inode_buffer(ip, &dibh);
if (error)
goto out;
-
- if (er->er_flags & GFS2_ERF_MODE) {
- gfs2_assert_withdraw(GFS2_SB(&ip->i_inode),
- (ip->i_inode.i_mode & S_IFMT) == (er->er_mode & S_IFMT));
- ip->i_inode.i_mode = er->er_mode;
- }
ip->i_inode.i_ctime = CURRENT_TIME;
gfs2_trans_add_bh(ip->i_gl, dibh, 1);
gfs2_dinode_out(ip, dibh->b_data);
@@ -894,7 +893,8 @@
int stuffed;
int error;
- stuffed = ea_calc_size(GFS2_SB(&ip->i_inode), es->es_er, &size);
+ stuffed = ea_calc_size(GFS2_SB(&ip->i_inode), es->es_er->er_name_len,
+ es->es_er->er_data_len, &size);
if (ea->ea_type == GFS2_EATYPE_UNUSED) {
if (GFS2_EA_REC_LEN(ea) < size)
@@ -1005,15 +1005,22 @@
return error;
}
-static int ea_set_i(struct gfs2_inode *ip, struct gfs2_ea_request *er,
- struct gfs2_ea_location *el)
+static int ea_set_i(struct gfs2_inode *ip, int type, const char *name,
+ const void *value, size_t size, struct gfs2_ea_location *el)
{
+ struct gfs2_ea_request er;
struct ea_set es;
unsigned int blks = 2;
int error;
+ er.er_type = type;
+ er.er_name = name;
+ er.er_data = (void *)value;
+ er.er_name_len = strlen(name);
+ er.er_data_len = size;
+
memset(&es, 0, sizeof(struct ea_set));
- es.es_er = er;
+ es.es_er = &er;
es.es_el = el;
error = ea_foreach(ip, ea_set_simple, &es);
@@ -1024,10 +1031,10 @@
if (!(ip->i_diskflags & GFS2_DIF_EA_INDIRECT))
blks++;
- if (GFS2_EAREQ_SIZE_STUFFED(er) > GFS2_SB(&ip->i_inode)->sd_jbsize)
- blks += DIV_ROUND_UP(er->er_data_len, GFS2_SB(&ip->i_inode)->sd_jbsize);
+ if (GFS2_EAREQ_SIZE_STUFFED(&er) > GFS2_SB(&ip->i_inode)->sd_jbsize)
+ blks += DIV_ROUND_UP(er.er_data_len, GFS2_SB(&ip->i_inode)->sd_jbsize);
- return ea_alloc_skeleton(ip, er, blks, ea_set_block, el);
+ return ea_alloc_skeleton(ip, &er, blks, ea_set_block, el);
}
static int ea_set_remove_unstuffed(struct gfs2_inode *ip,
@@ -1042,74 +1049,6 @@
return ea_remove_unstuffed(ip, el->el_bh, el->el_ea, el->el_prev,0);
}
-int gfs2_ea_set_i(struct gfs2_inode *ip, struct gfs2_ea_request *er)
-{
- struct gfs2_ea_location el;
- int error;
-
- if (!ip->i_eattr) {
- if (er->er_flags & XATTR_REPLACE)
- return -ENODATA;
- return ea_init(ip, er);
- }
-
- error = gfs2_ea_find(ip, er, &el);
- if (error)
- return error;
-
- if (el.el_ea) {
- if (ip->i_diskflags & GFS2_DIF_APPENDONLY) {
- brelse(el.el_bh);
- return -EPERM;
- }
-
- error = -EEXIST;
- if (!(er->er_flags & XATTR_CREATE)) {
- int unstuffed = !GFS2_EA_IS_STUFFED(el.el_ea);
- error = ea_set_i(ip, er, &el);
- if (!error && unstuffed)
- ea_set_remove_unstuffed(ip, &el);
- }
-
- brelse(el.el_bh);
- } else {
- error = -ENODATA;
- if (!(er->er_flags & XATTR_REPLACE))
- error = ea_set_i(ip, er, NULL);
- }
-
- return error;
-}
-
-int gfs2_ea_set(struct gfs2_inode *ip, struct gfs2_ea_request *er)
-{
- struct gfs2_holder i_gh;
- int error;
-
- if (!er->er_name_len || er->er_name_len > GFS2_EA_MAX_NAME_LEN)
- return -EINVAL;
- if (!er->er_data || !er->er_data_len) {
- er->er_data = NULL;
- er->er_data_len = 0;
- }
- error = ea_check_size(GFS2_SB(&ip->i_inode), er);
- if (error)
- return error;
-
- error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
- if (error)
- return error;
-
- if (IS_IMMUTABLE(&ip->i_inode))
- error = -EPERM;
- else
- error = gfs2_ea_ops[er->er_type]->eo_set(ip, er);
-
- gfs2_glock_dq_uninit(&i_gh);
-
- return error;
-}
-
static int ea_remove_stuffed(struct gfs2_inode *ip, struct gfs2_ea_location *el)
{
struct gfs2_ea_header *ea = el->el_ea;
@@ -1131,8 +1070,9 @@
if (GFS2_EA_IS_LAST(ea))
prev->ea_flags |= GFS2_EAFLAG_LAST;
- } else
+ } else {
ea->ea_type = GFS2_EATYPE_UNUSED;
+ }
error = gfs2_meta_inode_buffer(ip, &dibh);
if (!error) {
@@ -1147,15 +1087,29 @@
return error;
}
-int gfs2_ea_remove_i(struct gfs2_inode *ip, struct gfs2_ea_request *er)
+/**
+ * gfs2_xattr_remove - Remove a GFS2 extended attribute
+ * @inode: The inode
+ * @type: The type of the extended attribute
+ * @name: The name of the extended attribute
+ *
+ * This is not called directly by the VFS since we use the (common)
+ * scheme of making a "set with NULL data" mean a remove request. Note
+ * that this is different from a set with zero length data.
+ *
+ * Returns: 0, or errno on failure
+ */
+
+static int gfs2_xattr_remove(struct inode *inode, int type, const char *name)
{
+ struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_ea_location el;
int error;
if (!ip->i_eattr)
return -ENODATA;
- error = gfs2_ea_find(ip, er, &el);
+ error = gfs2_ea_find(ip, type, name, &el);
if (error)
return error;
if (!el.el_ea)
@@ -1164,8 +1118,7 @@
if (GFS2_EA_IS_STUFFED(el.el_ea))
error = ea_remove_stuffed(ip, &el);
else
- error = ea_remove_unstuffed(ip, el.el_bh, el.el_ea, el.el_prev,
- 0);
+ error = ea_remove_unstuffed(ip, el.el_bh, el.el_ea, el.el_prev, 0);
brelse(el.el_bh);
@@ -1173,31 +1126,70 @@
}
/**
- * gfs2_ea_remove - sets (or creates or replaces) an extended attribute
- * @ip: pointer to the inode of the target file
- * @er: request information
+ * gfs2_xattr_set - Set (or remove) a GFS2 extended attribute
+ * @inode: The inode
+ * @type: The type of the extended attribute
+ * @name: The name of the extended attribute
+ * @value: The value of the extended attribute (NULL for remove)
+ * @size: The size of the @value argument
+ * @flags: Create or Replace
*
- * Returns: errno
+ * See gfs2_xattr_remove() for details of the removal of xattrs.
+ *
+ * Returns: 0 or errno on failure
*/
-int gfs2_ea_remove(struct gfs2_inode *ip, struct gfs2_ea_request *er)
+int gfs2_xattr_set(struct inode *inode, int type, const char *name,
+ const void *value, size_t size, int flags)
{
- struct gfs2_holder i_gh;
+ struct gfs2_sbd *sdp = GFS2_SB(inode);
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_ea_location el;
+ unsigned int namel = strlen(name);
int error;
- if (!er->er_name_len || er->er_name_len > GFS2_EA_MAX_NAME_LEN)
- return -EINVAL;
+ if (IS_IMMUTABLE(inode) || IS_APPEND(inode))
+ return -EPERM;
+ if (namel > GFS2_EA_MAX_NAME_LEN)
+ return -ERANGE;
- error = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &i_gh);
+ if (value == NULL)
+ return gfs2_xattr_remove(inode, type, name);
+
+ if (ea_check_size(sdp, namel, size))
+ return -ERANGE;
+
+ if (!ip->i_eattr) {
+ if (flags & XATTR_REPLACE)
+ return -ENODATA;
+ return ea_init(ip, type, name, value, size);
+ }
+
+ error = gfs2_ea_find(ip, type, name, &el);
if (error)
return error;
- if (IS_IMMUTABLE(&ip->i_inode) || IS_APPEND(&ip->i_inode))
- error = -EPERM;
- else
- error = gfs2_ea_ops[er->er_type]->eo_remove(ip, er);
+ if (el.el_ea) {
+ if (ip->i_diskflags & GFS2_DIF_APPENDONLY) {
+ brelse(el.el_bh);
+ return -EPERM;
+ }
- gfs2_glock_dq_uninit(&i_gh);
+ error = -EEXIST;
+ if (!(flags & XATTR_CREATE)) {
+ int unstuffed = !GFS2_EA_IS_STUFFED(el.el_ea);
+ error = ea_set_i(ip, type, name, value, size, &el);
+ if (!error && unstuffed)
+ ea_set_remove_unstuffed(ip, &el);
+ }
+
+ brelse(el.el_bh);
+ return error;
+ }
+
+ error = -ENODATA;
+ if (!(flags & XATTR_REPLACE))
+ error = ea_set_i(ip, type, name, value, size, NULL);
return error;
}
@@ -1503,3 +1495,64 @@
return error;
}
+static int gfs2_xattr_user_get(struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ return gfs2_xattr_get(inode, GFS2_EATYPE_USR, name, buffer, size);
+}
+
+static int gfs2_xattr_user_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return gfs2_xattr_set(inode, GFS2_EATYPE_USR, name, value, size, flags);
+}
+
+static int gfs2_xattr_system_get(struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ return gfs2_xattr_get(inode, GFS2_EATYPE_SYS, name, buffer, size);
+}
+
+static int gfs2_xattr_system_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return gfs2_xattr_set(inode, GFS2_EATYPE_SYS, name, value, size, flags);
+}
+
+static int gfs2_xattr_security_get(struct inode *inode, const char *name,
+ void *buffer, size_t size)
+{
+ return gfs2_xattr_get(inode, GFS2_EATYPE_SECURITY, name, buffer, size);
+}
+
+static int gfs2_xattr_security_set(struct inode *inode, const char *name,
+ const void *value, size_t size, int flags)
+{
+ return gfs2_xattr_set(inode, GFS2_EATYPE_SECURITY, name, value, size, flags);
+}
+
+static struct xattr_handler gfs2_xattr_user_handler = {
+ .prefix = XATTR_USER_PREFIX,
+ .get = gfs2_xattr_user_get,
+ .set = gfs2_xattr_user_set,
+};
+
+static struct xattr_handler gfs2_xattr_security_handler = {
+ .prefix = XATTR_SECURITY_PREFIX,
+ .get = gfs2_xattr_security_get,
+ .set = gfs2_xattr_security_set,
+};
+
+static struct xattr_handler gfs2_xattr_system_handler = {
+ .prefix = XATTR_SYSTEM_PREFIX,
+ .get = gfs2_xattr_system_get,
+ .set = gfs2_xattr_system_set,
+};
+
+struct xattr_handler *gfs2_xattr_handlers[] = {
+ &gfs2_xattr_user_handler,
+ &gfs2_xattr_security_handler,
+ &gfs2_xattr_system_handler,
+ NULL,
+};
+