xfs: split out attribute listing code into separate file
The attribute listing code is not used by userspace, so like the
directory readdir code, split it out into a separate file to
minimise the differences between the filesystem shared with libxfs
in userspace.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
new file mode 100644
index 0000000..cbc80d4
--- /dev/null
+++ b/fs/xfs/xfs_attr_list.c
@@ -0,0 +1,655 @@
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * Copyright (c) 2013 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_types.h"
+#include "xfs_bit.h"
+#include "xfs_log.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_mount.h"
+#include "xfs_da_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_alloc.h"
+#include "xfs_btree.h"
+#include "xfs_attr_sf.h"
+#include "xfs_attr_remote.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_inode_item.h"
+#include "xfs_bmap.h"
+#include "xfs_attr.h"
+#include "xfs_attr_leaf.h"
+#include "xfs_error.h"
+#include "xfs_trace.h"
+#include "xfs_buf_item.h"
+#include "xfs_cksum.h"
+
+STATIC int
+xfs_attr_shortform_compare(const void *a, const void *b)
+{
+ xfs_attr_sf_sort_t *sa, *sb;
+
+ sa = (xfs_attr_sf_sort_t *)a;
+ sb = (xfs_attr_sf_sort_t *)b;
+ if (sa->hash < sb->hash) {
+ return(-1);
+ } else if (sa->hash > sb->hash) {
+ return(1);
+ } else {
+ return(sa->entno - sb->entno);
+ }
+}
+
+#define XFS_ISRESET_CURSOR(cursor) \
+ (!((cursor)->initted) && !((cursor)->hashval) && \
+ !((cursor)->blkno) && !((cursor)->offset))
+/*
+ * Copy out entries of shortform attribute lists for attr_list().
+ * Shortform attribute lists are not stored in hashval sorted order.
+ * If the output buffer is not large enough to hold them all, then we
+ * we have to calculate each entries' hashvalue and sort them before
+ * we can begin returning them to the user.
+ */
+int
+xfs_attr_shortform_list(xfs_attr_list_context_t *context)
+{
+ attrlist_cursor_kern_t *cursor;
+ xfs_attr_sf_sort_t *sbuf, *sbp;
+ xfs_attr_shortform_t *sf;
+ xfs_attr_sf_entry_t *sfe;
+ xfs_inode_t *dp;
+ int sbsize, nsbuf, count, i;
+ int error;
+
+ ASSERT(context != NULL);
+ dp = context->dp;
+ ASSERT(dp != NULL);
+ ASSERT(dp->i_afp != NULL);
+ sf = (xfs_attr_shortform_t *)dp->i_afp->if_u1.if_data;
+ ASSERT(sf != NULL);
+ if (!sf->hdr.count)
+ return(0);
+ cursor = context->cursor;
+ ASSERT(cursor != NULL);
+
+ trace_xfs_attr_list_sf(context);
+
+ /*
+ * If the buffer is large enough and the cursor is at the start,
+ * do not bother with sorting since we will return everything in
+ * one buffer and another call using the cursor won't need to be
+ * made.
+ * Note the generous fudge factor of 16 overhead bytes per entry.
+ * If bufsize is zero then put_listent must be a search function
+ * and can just scan through what we have.
+ */
+ if (context->bufsize == 0 ||
+ (XFS_ISRESET_CURSOR(cursor) &&
+ (dp->i_afp->if_bytes + sf->hdr.count * 16) < context->bufsize)) {
+ for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
+ error = context->put_listent(context,
+ sfe->flags,
+ sfe->nameval,
+ (int)sfe->namelen,
+ (int)sfe->valuelen,
+ &sfe->nameval[sfe->namelen]);
+
+ /*
+ * Either search callback finished early or
+ * didn't fit it all in the buffer after all.
+ */
+ if (context->seen_enough)
+ break;
+
+ if (error)
+ return error;
+ sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
+ }
+ trace_xfs_attr_list_sf_all(context);
+ return(0);
+ }
+
+ /* do no more for a search callback */
+ if (context->bufsize == 0)
+ return 0;
+
+ /*
+ * It didn't all fit, so we have to sort everything on hashval.
+ */
+ sbsize = sf->hdr.count * sizeof(*sbuf);
+ sbp = sbuf = kmem_alloc(sbsize, KM_SLEEP | KM_NOFS);
+
+ /*
+ * Scan the attribute list for the rest of the entries, storing
+ * the relevant info from only those that match into a buffer.
+ */
+ nsbuf = 0;
+ for (i = 0, sfe = &sf->list[0]; i < sf->hdr.count; i++) {
+ if (unlikely(
+ ((char *)sfe < (char *)sf) ||
+ ((char *)sfe >= ((char *)sf + dp->i_afp->if_bytes)))) {
+ XFS_CORRUPTION_ERROR("xfs_attr_shortform_list",
+ XFS_ERRLEVEL_LOW,
+ context->dp->i_mount, sfe);
+ kmem_free(sbuf);
+ return XFS_ERROR(EFSCORRUPTED);
+ }
+
+ sbp->entno = i;
+ sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
+ sbp->name = sfe->nameval;
+ sbp->namelen = sfe->namelen;
+ /* These are bytes, and both on-disk, don't endian-flip */
+ sbp->valuelen = sfe->valuelen;
+ sbp->flags = sfe->flags;
+ sfe = XFS_ATTR_SF_NEXTENTRY(sfe);
+ sbp++;
+ nsbuf++;
+ }
+
+ /*
+ * Sort the entries on hash then entno.
+ */
+ xfs_sort(sbuf, nsbuf, sizeof(*sbuf), xfs_attr_shortform_compare);
+
+ /*
+ * Re-find our place IN THE SORTED LIST.
+ */
+ count = 0;
+ cursor->initted = 1;
+ cursor->blkno = 0;
+ for (sbp = sbuf, i = 0; i < nsbuf; i++, sbp++) {
+ if (sbp->hash == cursor->hashval) {
+ if (cursor->offset == count) {
+ break;
+ }
+ count++;
+ } else if (sbp->hash > cursor->hashval) {
+ break;
+ }
+ }
+ if (i == nsbuf) {
+ kmem_free(sbuf);
+ return(0);
+ }
+
+ /*
+ * Loop putting entries into the user buffer.
+ */
+ for ( ; i < nsbuf; i++, sbp++) {
+ if (cursor->hashval != sbp->hash) {
+ cursor->hashval = sbp->hash;
+ cursor->offset = 0;
+ }
+ error = context->put_listent(context,
+ sbp->flags,
+ sbp->name,
+ sbp->namelen,
+ sbp->valuelen,
+ &sbp->name[sbp->namelen]);
+ if (error)
+ return error;
+ if (context->seen_enough)
+ break;
+ cursor->offset++;
+ }
+
+ kmem_free(sbuf);
+ return(0);
+}
+
+STATIC int
+xfs_attr_node_list(xfs_attr_list_context_t *context)
+{
+ attrlist_cursor_kern_t *cursor;
+ xfs_attr_leafblock_t *leaf;
+ xfs_da_intnode_t *node;
+ struct xfs_attr3_icleaf_hdr leafhdr;
+ struct xfs_da3_icnode_hdr nodehdr;
+ struct xfs_da_node_entry *btree;
+ int error, i;
+ struct xfs_buf *bp;
+
+ trace_xfs_attr_node_list(context);
+
+ cursor = context->cursor;
+ cursor->initted = 1;
+
+ /*
+ * Do all sorts of validation on the passed-in cursor structure.
+ * If anything is amiss, ignore the cursor and look up the hashval
+ * starting from the btree root.
+ */
+ bp = NULL;
+ if (cursor->blkno > 0) {
+ error = xfs_da3_node_read(NULL, context->dp, cursor->blkno, -1,
+ &bp, XFS_ATTR_FORK);
+ if ((error != 0) && (error != EFSCORRUPTED))
+ return(error);
+ if (bp) {
+ struct xfs_attr_leaf_entry *entries;
+
+ node = bp->b_addr;
+ switch (be16_to_cpu(node->hdr.info.magic)) {
+ case XFS_DA_NODE_MAGIC:
+ case XFS_DA3_NODE_MAGIC:
+ trace_xfs_attr_list_wrong_blk(context);
+ xfs_trans_brelse(NULL, bp);
+ bp = NULL;
+ break;
+ case XFS_ATTR_LEAF_MAGIC:
+ case XFS_ATTR3_LEAF_MAGIC:
+ leaf = bp->b_addr;
+ xfs_attr3_leaf_hdr_from_disk(&leafhdr, leaf);
+ entries = xfs_attr3_leaf_entryp(leaf);
+ if (cursor->hashval > be32_to_cpu(
+ entries[leafhdr.count - 1].hashval)) {
+ trace_xfs_attr_list_wrong_blk(context);
+ xfs_trans_brelse(NULL, bp);
+ bp = NULL;
+ } else if (cursor->hashval <= be32_to_cpu(
+ entries[0].hashval)) {
+ trace_xfs_attr_list_wrong_blk(context);
+ xfs_trans_brelse(NULL, bp);
+ bp = NULL;
+ }
+ break;
+ default:
+ trace_xfs_attr_list_wrong_blk(context);
+ xfs_trans_brelse(NULL, bp);
+ bp = NULL;
+ }
+ }
+ }
+
+ /*
+ * We did not find what we expected given the cursor's contents,
+ * so we start from the top and work down based on the hash value.
+ * Note that start of node block is same as start of leaf block.
+ */
+ if (bp == NULL) {
+ cursor->blkno = 0;
+ for (;;) {
+ __uint16_t magic;
+
+ error = xfs_da3_node_read(NULL, context->dp,
+ cursor->blkno, -1, &bp,
+ XFS_ATTR_FORK);
+ if (error)
+ return(error);
+ node = bp->b_addr;
+ magic = be16_to_cpu(node->hdr.info.magic);
+ if (magic == XFS_ATTR_LEAF_MAGIC ||
+ magic == XFS_ATTR3_LEAF_MAGIC)
+ break;
+ if (magic != XFS_DA_NODE_MAGIC &&
+ magic != XFS_DA3_NODE_MAGIC) {
+ XFS_CORRUPTION_ERROR("xfs_attr_node_list(3)",
+ XFS_ERRLEVEL_LOW,
+ context->dp->i_mount,
+ node);
+ xfs_trans_brelse(NULL, bp);
+ return XFS_ERROR(EFSCORRUPTED);
+ }
+
+ xfs_da3_node_hdr_from_disk(&nodehdr, node);
+ btree = xfs_da3_node_tree_p(node);
+ for (i = 0; i < nodehdr.count; btree++, i++) {
+ if (cursor->hashval
+ <= be32_to_cpu(btree->hashval)) {
+ cursor->blkno = be32_to_cpu(btree->before);
+ trace_xfs_attr_list_node_descend(context,
+ btree);
+ break;
+ }
+ }
+ if (i == nodehdr.count) {
+ xfs_trans_brelse(NULL, bp);
+ return 0;
+ }
+ xfs_trans_brelse(NULL, bp);
+ }
+ }
+ ASSERT(bp != NULL);
+
+ /*
+ * Roll upward through the blocks, processing each leaf block in
+ * order. As long as there is space in the result buffer, keep
+ * adding the information.
+ */
+ for (;;) {
+ leaf = bp->b_addr;
+ error = xfs_attr3_leaf_list_int(bp, context);
+ if (error) {
+ xfs_trans_brelse(NULL, bp);
+ return error;
+ }
+ xfs_attr3_leaf_hdr_from_disk(&leafhdr, leaf);
+ if (context->seen_enough || leafhdr.forw == 0)
+ break;
+ cursor->blkno = leafhdr.forw;
+ xfs_trans_brelse(NULL, bp);
+ error = xfs_attr3_leaf_read(NULL, context->dp, cursor->blkno, -1,
+ &bp);
+ if (error)
+ return error;
+ }
+ xfs_trans_brelse(NULL, bp);
+ return 0;
+}
+
+/*
+ * Copy out attribute list entries for attr_list(), for leaf attribute lists.
+ */
+int
+xfs_attr3_leaf_list_int(
+ struct xfs_buf *bp,
+ struct xfs_attr_list_context *context)
+{
+ struct attrlist_cursor_kern *cursor;
+ struct xfs_attr_leafblock *leaf;
+ struct xfs_attr3_icleaf_hdr ichdr;
+ struct xfs_attr_leaf_entry *entries;
+ struct xfs_attr_leaf_entry *entry;
+ int retval;
+ int i;
+
+ trace_xfs_attr_list_leaf(context);
+
+ leaf = bp->b_addr;
+ xfs_attr3_leaf_hdr_from_disk(&ichdr, leaf);
+ entries = xfs_attr3_leaf_entryp(leaf);
+
+ cursor = context->cursor;
+ cursor->initted = 1;
+
+ /*
+ * Re-find our place in the leaf block if this is a new syscall.
+ */
+ if (context->resynch) {
+ entry = &entries[0];
+ for (i = 0; i < ichdr.count; entry++, i++) {
+ if (be32_to_cpu(entry->hashval) == cursor->hashval) {
+ if (cursor->offset == context->dupcnt) {
+ context->dupcnt = 0;
+ break;
+ }
+ context->dupcnt++;
+ } else if (be32_to_cpu(entry->hashval) >
+ cursor->hashval) {
+ context->dupcnt = 0;
+ break;
+ }
+ }
+ if (i == ichdr.count) {
+ trace_xfs_attr_list_notfound(context);
+ return 0;
+ }
+ } else {
+ entry = &entries[0];
+ i = 0;
+ }
+ context->resynch = 0;
+
+ /*
+ * We have found our place, start copying out the new attributes.
+ */
+ retval = 0;
+ for (; i < ichdr.count; entry++, i++) {
+ if (be32_to_cpu(entry->hashval) != cursor->hashval) {
+ cursor->hashval = be32_to_cpu(entry->hashval);
+ cursor->offset = 0;
+ }
+
+ if (entry->flags & XFS_ATTR_INCOMPLETE)
+ continue; /* skip incomplete entries */
+
+ if (entry->flags & XFS_ATTR_LOCAL) {
+ xfs_attr_leaf_name_local_t *name_loc =
+ xfs_attr3_leaf_name_local(leaf, i);
+
+ retval = context->put_listent(context,
+ entry->flags,
+ name_loc->nameval,
+ (int)name_loc->namelen,
+ be16_to_cpu(name_loc->valuelen),
+ &name_loc->nameval[name_loc->namelen]);
+ if (retval)
+ return retval;
+ } else {
+ xfs_attr_leaf_name_remote_t *name_rmt =
+ xfs_attr3_leaf_name_remote(leaf, i);
+
+ int valuelen = be32_to_cpu(name_rmt->valuelen);
+
+ if (context->put_value) {
+ xfs_da_args_t args;
+
+ memset((char *)&args, 0, sizeof(args));
+ args.dp = context->dp;
+ args.whichfork = XFS_ATTR_FORK;
+ args.valuelen = valuelen;
+ args.value = kmem_alloc(valuelen, KM_SLEEP | KM_NOFS);
+ args.rmtblkno = be32_to_cpu(name_rmt->valueblk);
+ args.rmtblkcnt = xfs_attr3_rmt_blocks(
+ args.dp->i_mount, valuelen);
+ retval = xfs_attr_rmtval_get(&args);
+ if (retval)
+ return retval;
+ retval = context->put_listent(context,
+ entry->flags,
+ name_rmt->name,
+ (int)name_rmt->namelen,
+ valuelen,
+ args.value);
+ kmem_free(args.value);
+ } else {
+ retval = context->put_listent(context,
+ entry->flags,
+ name_rmt->name,
+ (int)name_rmt->namelen,
+ valuelen,
+ NULL);
+ }
+ if (retval)
+ return retval;
+ }
+ if (context->seen_enough)
+ break;
+ cursor->offset++;
+ }
+ trace_xfs_attr_list_leaf_end(context);
+ return retval;
+}
+
+/*
+ * Copy out attribute entries for attr_list(), for leaf attribute lists.
+ */
+STATIC int
+xfs_attr_leaf_list(xfs_attr_list_context_t *context)
+{
+ int error;
+ struct xfs_buf *bp;
+
+ trace_xfs_attr_leaf_list(context);
+
+ context->cursor->blkno = 0;
+ error = xfs_attr3_leaf_read(NULL, context->dp, 0, -1, &bp);
+ if (error)
+ return XFS_ERROR(error);
+
+ error = xfs_attr3_leaf_list_int(bp, context);
+ xfs_trans_brelse(NULL, bp);
+ return XFS_ERROR(error);
+}
+
+int
+xfs_attr_list_int(
+ xfs_attr_list_context_t *context)
+{
+ int error;
+ xfs_inode_t *dp = context->dp;
+
+ XFS_STATS_INC(xs_attr_list);
+
+ if (XFS_FORCED_SHUTDOWN(dp->i_mount))
+ return EIO;
+
+ xfs_ilock(dp, XFS_ILOCK_SHARED);
+
+ /*
+ * Decide on what work routines to call based on the inode size.
+ */
+ if (!xfs_inode_hasattr(dp)) {
+ error = 0;
+ } else if (dp->i_d.di_aformat == XFS_DINODE_FMT_LOCAL) {
+ error = xfs_attr_shortform_list(context);
+ } else if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
+ error = xfs_attr_leaf_list(context);
+ } else {
+ error = xfs_attr_node_list(context);
+ }
+
+ xfs_iunlock(dp, XFS_ILOCK_SHARED);
+
+ return error;
+}
+
+#define ATTR_ENTBASESIZE /* minimum bytes used by an attr */ \
+ (((struct attrlist_ent *) 0)->a_name - (char *) 0)
+#define ATTR_ENTSIZE(namelen) /* actual bytes used by an attr */ \
+ ((ATTR_ENTBASESIZE + (namelen) + 1 + sizeof(u_int32_t)-1) \
+ & ~(sizeof(u_int32_t)-1))
+
+/*
+ * Format an attribute and copy it out to the user's buffer.
+ * Take care to check values and protect against them changing later,
+ * we may be reading them directly out of a user buffer.
+ */
+STATIC int
+xfs_attr_put_listent(
+ xfs_attr_list_context_t *context,
+ int flags,
+ unsigned char *name,
+ int namelen,
+ int valuelen,
+ unsigned char *value)
+{
+ struct attrlist *alist = (struct attrlist *)context->alist;
+ attrlist_ent_t *aep;
+ int arraytop;
+
+ ASSERT(!(context->flags & ATTR_KERNOVAL));
+ ASSERT(context->count >= 0);
+ ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
+ ASSERT(context->firstu >= sizeof(*alist));
+ ASSERT(context->firstu <= context->bufsize);
+
+ /*
+ * Only list entries in the right namespace.
+ */
+ if (((context->flags & ATTR_SECURE) == 0) !=
+ ((flags & XFS_ATTR_SECURE) == 0))
+ return 0;
+ if (((context->flags & ATTR_ROOT) == 0) !=
+ ((flags & XFS_ATTR_ROOT) == 0))
+ return 0;
+
+ arraytop = sizeof(*alist) +
+ context->count * sizeof(alist->al_offset[0]);
+ context->firstu -= ATTR_ENTSIZE(namelen);
+ if (context->firstu < arraytop) {
+ trace_xfs_attr_list_full(context);
+ alist->al_more = 1;
+ context->seen_enough = 1;
+ return 1;
+ }
+
+ aep = (attrlist_ent_t *)&context->alist[context->firstu];
+ aep->a_valuelen = valuelen;
+ memcpy(aep->a_name, name, namelen);
+ aep->a_name[namelen] = 0;
+ alist->al_offset[context->count++] = context->firstu;
+ alist->al_count = context->count;
+ trace_xfs_attr_list_add(context);
+ return 0;
+}
+
+/*
+ * Generate a list of extended attribute names and optionally
+ * also value lengths. Positive return value follows the XFS
+ * convention of being an error, zero or negative return code
+ * is the length of the buffer returned (negated), indicating
+ * success.
+ */
+int
+xfs_attr_list(
+ xfs_inode_t *dp,
+ char *buffer,
+ int bufsize,
+ int flags,
+ attrlist_cursor_kern_t *cursor)
+{
+ xfs_attr_list_context_t context;
+ struct attrlist *alist;
+ int error;
+
+ /*
+ * Validate the cursor.
+ */
+ if (cursor->pad1 || cursor->pad2)
+ return(XFS_ERROR(EINVAL));
+ if ((cursor->initted == 0) &&
+ (cursor->hashval || cursor->blkno || cursor->offset))
+ return XFS_ERROR(EINVAL);
+
+ /*
+ * Check for a properly aligned buffer.
+ */
+ if (((long)buffer) & (sizeof(int)-1))
+ return XFS_ERROR(EFAULT);
+ if (flags & ATTR_KERNOVAL)
+ bufsize = 0;
+
+ /*
+ * Initialize the output buffer.
+ */
+ memset(&context, 0, sizeof(context));
+ context.dp = dp;
+ context.cursor = cursor;
+ context.resynch = 1;
+ context.flags = flags;
+ context.alist = buffer;
+ context.bufsize = (bufsize & ~(sizeof(int)-1)); /* align */
+ context.firstu = context.bufsize;
+ context.put_listent = xfs_attr_put_listent;
+
+ alist = (struct attrlist *)context.alist;
+ alist->al_count = 0;
+ alist->al_more = 0;
+ alist->al_offset[0] = context.bufsize;
+
+ error = xfs_attr_list_int(&context);
+ ASSERT(error >= 0);
+ return error;
+}