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Diffstat (limited to 'fs/xfs/xfs_symlink.c')
-rw-r--r--fs/xfs/xfs_symlink.c529
1 files changed, 529 insertions, 0 deletions
diff --git a/fs/xfs/xfs_symlink.c b/fs/xfs/xfs_symlink.c
new file mode 100644
index 000000000000..7512c96c7f29
--- /dev/null
+++ b/fs/xfs/xfs_symlink.c
@@ -0,0 +1,529 @@
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * Copyright (c) 2012-2013 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_dir2.h"
+#include "xfs_mount.h"
+#include "xfs_da_btree.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_inode_item.h"
+#include "xfs_itable.h"
+#include "xfs_ialloc.h"
+#include "xfs_alloc.h"
+#include "xfs_bmap.h"
+#include "xfs_error.h"
+#include "xfs_quota.h"
+#include "xfs_utils.h"
+#include "xfs_trans_space.h"
+#include "xfs_log_priv.h"
+#include "xfs_trace.h"
+#include "xfs_symlink.h"
+
+void
+xfs_symlink_local_to_remote(
+ struct xfs_trans *tp,
+ struct xfs_buf *bp,
+ struct xfs_inode *ip,
+ struct xfs_ifork *ifp)
+{
+ /* remote symlink blocks are not verifiable until CRCs come along */
+ bp->b_ops = NULL;
+ memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
+}
+
+/* ----- Kernel only functions below ----- */
+
+STATIC int
+xfs_readlink_bmap(
+ xfs_inode_t *ip,
+ char *link)
+{
+ xfs_mount_t *mp = ip->i_mount;
+ int pathlen = ip->i_d.di_size;
+ int nmaps = XFS_SYMLINK_MAPS;
+ xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
+ xfs_daddr_t d;
+ int byte_cnt;
+ int n;
+ xfs_buf_t *bp;
+ int error = 0;
+
+ error = xfs_bmapi_read(ip, 0, XFS_B_TO_FSB(mp, pathlen), mval, &nmaps,
+ 0);
+ if (error)
+ goto out;
+
+ for (n = 0; n < nmaps; n++) {
+ d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
+ byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
+
+ bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt), 0, NULL);
+ if (!bp)
+ return XFS_ERROR(ENOMEM);
+ error = bp->b_error;
+ if (error) {
+ xfs_buf_ioerror_alert(bp, __func__);
+ xfs_buf_relse(bp);
+ goto out;
+ }
+ if (pathlen < byte_cnt)
+ byte_cnt = pathlen;
+ pathlen -= byte_cnt;
+
+ memcpy(link, bp->b_addr, byte_cnt);
+ xfs_buf_relse(bp);
+ }
+
+ link[ip->i_d.di_size] = '\0';
+ error = 0;
+
+ out:
+ return error;
+}
+
+int
+xfs_readlink(
+ xfs_inode_t *ip,
+ char *link)
+{
+ xfs_mount_t *mp = ip->i_mount;
+ xfs_fsize_t pathlen;
+ int error = 0;
+
+ trace_xfs_readlink(ip);
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return XFS_ERROR(EIO);
+
+ xfs_ilock(ip, XFS_ILOCK_SHARED);
+
+ pathlen = ip->i_d.di_size;
+ if (!pathlen)
+ goto out;
+
+ if (pathlen < 0 || pathlen > MAXPATHLEN) {
+ xfs_alert(mp, "%s: inode (%llu) bad symlink length (%lld)",
+ __func__, (unsigned long long) ip->i_ino,
+ (long long) pathlen);
+ ASSERT(0);
+ error = XFS_ERROR(EFSCORRUPTED);
+ goto out;
+ }
+
+
+ if (ip->i_df.if_flags & XFS_IFINLINE) {
+ memcpy(link, ip->i_df.if_u1.if_data, pathlen);
+ link[pathlen] = '\0';
+ } else {
+ error = xfs_readlink_bmap(ip, link);
+ }
+
+ out:
+ xfs_iunlock(ip, XFS_ILOCK_SHARED);
+ return error;
+}
+
+int
+xfs_symlink(
+ xfs_inode_t *dp,
+ struct xfs_name *link_name,
+ const char *target_path,
+ umode_t mode,
+ xfs_inode_t **ipp)
+{
+ xfs_mount_t *mp = dp->i_mount;
+ xfs_trans_t *tp;
+ xfs_inode_t *ip;
+ int error;
+ int pathlen;
+ xfs_bmap_free_t free_list;
+ xfs_fsblock_t first_block;
+ bool unlock_dp_on_error = false;
+ uint cancel_flags;
+ int committed;
+ xfs_fileoff_t first_fsb;
+ xfs_filblks_t fs_blocks;
+ int nmaps;
+ xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
+ xfs_daddr_t d;
+ const char *cur_chunk;
+ int byte_cnt;
+ int n;
+ xfs_buf_t *bp;
+ prid_t prid;
+ struct xfs_dquot *udqp, *gdqp;
+ uint resblks;
+
+ *ipp = NULL;
+ error = 0;
+ ip = NULL;
+ tp = NULL;
+
+ trace_xfs_symlink(dp, link_name);
+
+ if (XFS_FORCED_SHUTDOWN(mp))
+ return XFS_ERROR(EIO);
+
+ /*
+ * Check component lengths of the target path name.
+ */
+ pathlen = strlen(target_path);
+ if (pathlen >= MAXPATHLEN) /* total string too long */
+ return XFS_ERROR(ENAMETOOLONG);
+
+ udqp = gdqp = NULL;
+ if (dp->i_d.di_flags & XFS_DIFLAG_PROJINHERIT)
+ prid = xfs_get_projid(dp);
+ else
+ prid = XFS_PROJID_DEFAULT;
+
+ /*
+ * Make sure that we have allocated dquot(s) on disk.
+ */
+ error = xfs_qm_vop_dqalloc(dp, current_fsuid(), current_fsgid(), prid,
+ XFS_QMOPT_QUOTALL | XFS_QMOPT_INHERIT, &udqp, &gdqp);
+ if (error)
+ goto std_return;
+
+ tp = xfs_trans_alloc(mp, XFS_TRANS_SYMLINK);
+ cancel_flags = XFS_TRANS_RELEASE_LOG_RES;
+ /*
+ * The symlink will fit into the inode data fork?
+ * There can't be any attributes so we get the whole variable part.
+ */
+ if (pathlen <= XFS_LITINO(mp, dp->i_d.di_version))
+ fs_blocks = 0;
+ else
+ fs_blocks = XFS_B_TO_FSB(mp, pathlen);
+ resblks = XFS_SYMLINK_SPACE_RES(mp, link_name->len, fs_blocks);
+ error = xfs_trans_reserve(tp, resblks, XFS_SYMLINK_LOG_RES(mp), 0,
+ XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
+ if (error == ENOSPC && fs_blocks == 0) {
+ resblks = 0;
+ error = xfs_trans_reserve(tp, 0, XFS_SYMLINK_LOG_RES(mp), 0,
+ XFS_TRANS_PERM_LOG_RES, XFS_SYMLINK_LOG_COUNT);
+ }
+ if (error) {
+ cancel_flags = 0;
+ goto error_return;
+ }
+
+ xfs_ilock(dp, XFS_ILOCK_EXCL | XFS_ILOCK_PARENT);
+ unlock_dp_on_error = true;
+
+ /*
+ * Check whether the directory allows new symlinks or not.
+ */
+ if (dp->i_d.di_flags & XFS_DIFLAG_NOSYMLINKS) {
+ error = XFS_ERROR(EPERM);
+ goto error_return;
+ }
+
+ /*
+ * Reserve disk quota : blocks and inode.
+ */
+ error = xfs_trans_reserve_quota(tp, mp, udqp, gdqp, resblks, 1, 0);
+ if (error)
+ goto error_return;
+
+ /*
+ * Check for ability to enter directory entry, if no space reserved.
+ */
+ error = xfs_dir_canenter(tp, dp, link_name, resblks);
+ if (error)
+ goto error_return;
+ /*
+ * Initialize the bmap freelist prior to calling either
+ * bmapi or the directory create code.
+ */
+ xfs_bmap_init(&free_list, &first_block);
+
+ /*
+ * Allocate an inode for the symlink.
+ */
+ error = xfs_dir_ialloc(&tp, dp, S_IFLNK | (mode & ~S_IFMT), 1, 0,
+ prid, resblks > 0, &ip, NULL);
+ if (error) {
+ if (error == ENOSPC)
+ goto error_return;
+ goto error1;
+ }
+
+ /*
+ * An error after we've joined dp to the transaction will result in the
+ * transaction cancel unlocking dp so don't do it explicitly in the
+ * error path.
+ */
+ xfs_trans_ijoin(tp, dp, XFS_ILOCK_EXCL);
+ unlock_dp_on_error = false;
+
+ /*
+ * Also attach the dquot(s) to it, if applicable.
+ */
+ xfs_qm_vop_create_dqattach(tp, ip, udqp, gdqp);
+
+ if (resblks)
+ resblks -= XFS_IALLOC_SPACE_RES(mp);
+ /*
+ * If the symlink will fit into the inode, write it inline.
+ */
+ if (pathlen <= XFS_IFORK_DSIZE(ip)) {
+ xfs_idata_realloc(ip, pathlen, XFS_DATA_FORK);
+ memcpy(ip->i_df.if_u1.if_data, target_path, pathlen);
+ ip->i_d.di_size = pathlen;
+
+ /*
+ * The inode was initially created in extent format.
+ */
+ ip->i_df.if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
+ ip->i_df.if_flags |= XFS_IFINLINE;
+
+ ip->i_d.di_format = XFS_DINODE_FMT_LOCAL;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_DDATA | XFS_ILOG_CORE);
+
+ } else {
+ first_fsb = 0;
+ nmaps = XFS_SYMLINK_MAPS;
+
+ error = xfs_bmapi_write(tp, ip, first_fsb, fs_blocks,
+ XFS_BMAPI_METADATA, &first_block, resblks,
+ mval, &nmaps, &free_list);
+ if (error)
+ goto error2;
+
+ if (resblks)
+ resblks -= fs_blocks;
+ ip->i_d.di_size = pathlen;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+
+ cur_chunk = target_path;
+ for (n = 0; n < nmaps; n++) {
+ d = XFS_FSB_TO_DADDR(mp, mval[n].br_startblock);
+ byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
+ bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
+ BTOBB(byte_cnt), 0);
+ if (!bp) {
+ error = ENOMEM;
+ goto error2;
+ }
+ if (pathlen < byte_cnt) {
+ byte_cnt = pathlen;
+ }
+ pathlen -= byte_cnt;
+
+ memcpy(bp->b_addr, cur_chunk, byte_cnt);
+ cur_chunk += byte_cnt;
+
+ xfs_trans_log_buf(tp, bp, 0, byte_cnt - 1);
+ }
+ }
+
+ /*
+ * Create the directory entry for the symlink.
+ */
+ error = xfs_dir_createname(tp, dp, link_name, ip->i_ino,
+ &first_block, &free_list, resblks);
+ if (error)
+ goto error2;
+ xfs_trans_ichgtime(tp, dp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
+ xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE);
+
+ /*
+ * If this is a synchronous mount, make sure that the
+ * symlink transaction goes to disk before returning to
+ * the user.
+ */
+ if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC)) {
+ xfs_trans_set_sync(tp);
+ }
+
+ error = xfs_bmap_finish(&tp, &free_list, &committed);
+ if (error) {
+ goto error2;
+ }
+ error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES);
+ xfs_qm_dqrele(udqp);
+ xfs_qm_dqrele(gdqp);
+
+ *ipp = ip;
+ return 0;
+
+ error2:
+ IRELE(ip);
+ error1:
+ xfs_bmap_cancel(&free_list);
+ cancel_flags |= XFS_TRANS_ABORT;
+ error_return:
+ xfs_trans_cancel(tp, cancel_flags);
+ xfs_qm_dqrele(udqp);
+ xfs_qm_dqrele(gdqp);
+
+ if (unlock_dp_on_error)
+ xfs_iunlock(dp, XFS_ILOCK_EXCL);
+ std_return:
+ return error;
+}
+
+/*
+ * Free a symlink that has blocks associated with it.
+ */
+STATIC int
+xfs_inactive_symlink_rmt(
+ xfs_inode_t *ip,
+ xfs_trans_t **tpp)
+{
+ xfs_buf_t *bp;
+ int committed;
+ int done;
+ int error;
+ xfs_fsblock_t first_block;
+ xfs_bmap_free_t free_list;
+ int i;
+ xfs_mount_t *mp;
+ xfs_bmbt_irec_t mval[XFS_SYMLINK_MAPS];
+ int nmaps;
+ xfs_trans_t *ntp;
+ int size;
+ xfs_trans_t *tp;
+
+ tp = *tpp;
+ mp = ip->i_mount;
+ ASSERT(ip->i_d.di_size > XFS_IFORK_DSIZE(ip));
+ /*
+ * We're freeing a symlink that has some
+ * blocks allocated to it. Free the
+ * blocks here. We know that we've got
+ * either 1 or 2 extents and that we can
+ * free them all in one bunmapi call.
+ */
+ ASSERT(ip->i_d.di_nextents > 0 && ip->i_d.di_nextents <= 2);
+
+ /*
+ * Lock the inode, fix the size, and join it to the transaction.
+ * Hold it so in the normal path, we still have it locked for
+ * the second transaction. In the error paths we need it
+ * held so the cancel won't rele it, see below.
+ */
+ size = (int)ip->i_d.di_size;
+ ip->i_d.di_size = 0;
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ /*
+ * Find the block(s) so we can inval and unmap them.
+ */
+ done = 0;
+ xfs_bmap_init(&free_list, &first_block);
+ nmaps = ARRAY_SIZE(mval);
+ error = xfs_bmapi_read(ip, 0, XFS_B_TO_FSB(mp, size),
+ mval, &nmaps, 0);
+ if (error)
+ goto error0;
+ /*
+ * Invalidate the block(s).
+ */
+ for (i = 0; i < nmaps; i++) {
+ bp = xfs_trans_get_buf(tp, mp->m_ddev_targp,
+ XFS_FSB_TO_DADDR(mp, mval[i].br_startblock),
+ XFS_FSB_TO_BB(mp, mval[i].br_blockcount), 0);
+ if (!bp) {
+ error = ENOMEM;
+ goto error1;
+ }
+ xfs_trans_binval(tp, bp);
+ }
+ /*
+ * Unmap the dead block(s) to the free_list.
+ */
+ if ((error = xfs_bunmapi(tp, ip, 0, size, XFS_BMAPI_METADATA, nmaps,
+ &first_block, &free_list, &done)))
+ goto error1;
+ ASSERT(done);
+ /*
+ * Commit the first transaction. This logs the EFI and the inode.
+ */
+ if ((error = xfs_bmap_finish(&tp, &free_list, &committed)))
+ goto error1;
+ /*
+ * The transaction must have been committed, since there were
+ * actually extents freed by xfs_bunmapi. See xfs_bmap_finish.
+ * The new tp has the extent freeing and EFDs.
+ */
+ ASSERT(committed);
+ /*
+ * The first xact was committed, so add the inode to the new one.
+ * Mark it dirty so it will be logged and moved forward in the log as
+ * part of every commit.
+ */
+ xfs_trans_ijoin(tp, ip, 0);
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ /*
+ * Get a new, empty transaction to return to our caller.
+ */
+ ntp = xfs_trans_dup(tp);
+ /*
+ * Commit the transaction containing extent freeing and EFDs.
+ * If we get an error on the commit here or on the reserve below,
+ * we need to unlock the inode since the new transaction doesn't
+ * have the inode attached.
+ */
+ error = xfs_trans_commit(tp, 0);
+ tp = ntp;
+ if (error) {
+ ASSERT(XFS_FORCED_SHUTDOWN(mp));
+ goto error0;
+ }
+ /*
+ * transaction commit worked ok so we can drop the extra ticket
+ * reference that we gained in xfs_trans_dup()
+ */
+ xfs_log_ticket_put(tp->t_ticket);
+
+ /*
+ * Remove the memory for extent descriptions (just bookkeeping).
+ */
+ if (ip->i_df.if_bytes)
+ xfs_idata_realloc(ip, -ip->i_df.if_bytes, XFS_DATA_FORK);
+ ASSERT(ip->i_df.if_bytes == 0);
+ /*
+ * Put an itruncate log reservation in the new transaction
+ * for our caller.
+ */
+ if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0,
+ XFS_TRANS_PERM_LOG_RES, XFS_ITRUNCATE_LOG_COUNT))) {
+ ASSERT(XFS_FORCED_SHUTDOWN(mp));
+ goto error0;
+ }
+
+ xfs_trans_ijoin(tp, ip, 0);
+ *tpp = tp;
+ return 0;
+
+ error1:
+ xfs_bmap_cancel(&free_list);
+ error0:
+ return error;
+}