From abec5f2bf991a03b055be36d918cd6f8f58cc83e Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Mon, 12 Aug 2013 20:49:38 +1000 Subject: 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 Reviewed-by: Mark Tinguely Signed-off-by: Ben Myers --- fs/xfs/xfs_attr_list.c | 655 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 655 insertions(+) create mode 100644 fs/xfs/xfs_attr_list.c (limited to 'fs/xfs/xfs_attr_list.c') diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c new file mode 100644 index 000000000000..cbc80d485177 --- /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; +} -- cgit v1.2.3-59-g8ed1b