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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/xfs/xfs_utils.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/xfs/xfs_utils.c')
-rw-r--r-- | fs/xfs/xfs_utils.c | 488 |
1 files changed, 488 insertions, 0 deletions
diff --git a/fs/xfs/xfs_utils.c b/fs/xfs/xfs_utils.c new file mode 100644 index 0000000..816b945 --- /dev/null +++ b/fs/xfs/xfs_utils.c @@ -0,0 +1,488 @@ +/* + * Copyright (c) 2000-2002 Silicon Graphics, Inc. All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2 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. + * + * Further, this software is distributed without any warranty that it is + * free of the rightful claim of any third person regarding infringement + * or the like. Any license provided herein, whether implied or + * otherwise, applies only to this software file. Patent licenses, if + * any, provided herein do not apply to combinations of this program with + * other software, or any other product whatsoever. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston MA 02111-1307, USA. + * + * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, + * Mountain View, CA 94043, or: + * + * http://www.sgi.com + * + * For further information regarding this notice, see: + * + * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ + */ + +#include "xfs.h" +#include "xfs_macros.h" +#include "xfs_types.h" +#include "xfs_inum.h" +#include "xfs_log.h" +#include "xfs_trans.h" +#include "xfs_sb.h" +#include "xfs_dir.h" +#include "xfs_dir2.h" +#include "xfs_dmapi.h" +#include "xfs_mount.h" +#include "xfs_bmap_btree.h" +#include "xfs_attr_sf.h" +#include "xfs_dir_sf.h" +#include "xfs_dir2_sf.h" +#include "xfs_dinode.h" +#include "xfs_inode_item.h" +#include "xfs_inode.h" +#include "xfs_bmap.h" +#include "xfs_error.h" +#include "xfs_quota.h" +#include "xfs_rw.h" +#include "xfs_itable.h" +#include "xfs_utils.h" + +/* + * xfs_get_dir_entry is used to get a reference to an inode given + * its parent directory inode and the name of the file. It does + * not lock the child inode, and it unlocks the directory before + * returning. The directory's generation number is returned for + * use by a later call to xfs_lock_dir_and_entry. + */ +int +xfs_get_dir_entry( + vname_t *dentry, + xfs_inode_t **ipp) +{ + vnode_t *vp; + bhv_desc_t *bdp; + + vp = VNAME_TO_VNODE(dentry); + bdp = vn_bhv_lookup_unlocked(VN_BHV_HEAD(vp), &xfs_vnodeops); + if (!bdp) { + *ipp = NULL; + return XFS_ERROR(ENOENT); + } + VN_HOLD(vp); + *ipp = XFS_BHVTOI(bdp); + return 0; +} + +int +xfs_dir_lookup_int( + bhv_desc_t *dir_bdp, + uint lock_mode, + vname_t *dentry, + xfs_ino_t *inum, + xfs_inode_t **ipp) +{ + vnode_t *dir_vp; + xfs_inode_t *dp; + int error; + + dir_vp = BHV_TO_VNODE(dir_bdp); + vn_trace_entry(dir_vp, __FUNCTION__, (inst_t *)__return_address); + + dp = XFS_BHVTOI(dir_bdp); + + error = XFS_DIR_LOOKUP(dp->i_mount, NULL, dp, + VNAME(dentry), VNAMELEN(dentry), inum); + if (!error) { + /* + * Unlock the directory. We do this because we can't + * hold the directory lock while doing the vn_get() + * in xfs_iget(). Doing so could cause us to hold + * a lock while waiting for the inode to finish + * being inactive while it's waiting for a log + * reservation in the inactive routine. + */ + xfs_iunlock(dp, lock_mode); + error = xfs_iget(dp->i_mount, NULL, *inum, 0, 0, ipp, 0); + xfs_ilock(dp, lock_mode); + + if (error) { + *ipp = NULL; + } else if ((*ipp)->i_d.di_mode == 0) { + /* + * The inode has been freed. Something is + * wrong so just get out of here. + */ + xfs_iunlock(dp, lock_mode); + xfs_iput_new(*ipp, 0); + *ipp = NULL; + xfs_ilock(dp, lock_mode); + error = XFS_ERROR(ENOENT); + } + } + return error; +} + +/* + * Allocates a new inode from disk and return a pointer to the + * incore copy. This routine will internally commit the current + * transaction and allocate a new one if the Space Manager needed + * to do an allocation to replenish the inode free-list. + * + * This routine is designed to be called from xfs_create and + * xfs_create_dir. + * + */ +int +xfs_dir_ialloc( + xfs_trans_t **tpp, /* input: current transaction; + output: may be a new transaction. */ + xfs_inode_t *dp, /* directory within whose allocate + the inode. */ + mode_t mode, + nlink_t nlink, + xfs_dev_t rdev, + cred_t *credp, + prid_t prid, /* project id */ + int okalloc, /* ok to allocate new space */ + xfs_inode_t **ipp, /* pointer to inode; it will be + locked. */ + int *committed) + +{ + xfs_trans_t *tp; + xfs_trans_t *ntp; + xfs_inode_t *ip; + xfs_buf_t *ialloc_context = NULL; + boolean_t call_again = B_FALSE; + int code; + uint log_res; + uint log_count; + void *dqinfo; + uint tflags; + + tp = *tpp; + ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES); + + /* + * xfs_ialloc will return a pointer to an incore inode if + * the Space Manager has an available inode on the free + * list. Otherwise, it will do an allocation and replenish + * the freelist. Since we can only do one allocation per + * transaction without deadlocks, we will need to commit the + * current transaction and start a new one. We will then + * need to call xfs_ialloc again to get the inode. + * + * If xfs_ialloc did an allocation to replenish the freelist, + * it returns the bp containing the head of the freelist as + * ialloc_context. We will hold a lock on it across the + * transaction commit so that no other process can steal + * the inode(s) that we've just allocated. + */ + code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid, okalloc, + &ialloc_context, &call_again, &ip); + + /* + * Return an error if we were unable to allocate a new inode. + * This should only happen if we run out of space on disk or + * encounter a disk error. + */ + if (code) { + *ipp = NULL; + return code; + } + if (!call_again && (ip == NULL)) { + *ipp = NULL; + return XFS_ERROR(ENOSPC); + } + + /* + * If call_again is set, then we were unable to get an + * inode in one operation. We need to commit the current + * transaction and call xfs_ialloc() again. It is guaranteed + * to succeed the second time. + */ + if (call_again) { + + /* + * Normally, xfs_trans_commit releases all the locks. + * We call bhold to hang on to the ialloc_context across + * the commit. Holding this buffer prevents any other + * processes from doing any allocations in this + * allocation group. + */ + xfs_trans_bhold(tp, ialloc_context); + /* + * Save the log reservation so we can use + * them in the next transaction. + */ + log_res = xfs_trans_get_log_res(tp); + log_count = xfs_trans_get_log_count(tp); + + /* + * We want the quota changes to be associated with the next + * transaction, NOT this one. So, detach the dqinfo from this + * and attach it to the next transaction. + */ + dqinfo = NULL; + tflags = 0; + if (tp->t_dqinfo) { + dqinfo = (void *)tp->t_dqinfo; + tp->t_dqinfo = NULL; + tflags = tp->t_flags & XFS_TRANS_DQ_DIRTY; + tp->t_flags &= ~(XFS_TRANS_DQ_DIRTY); + } + + ntp = xfs_trans_dup(tp); + code = xfs_trans_commit(tp, 0, NULL); + tp = ntp; + if (committed != NULL) { + *committed = 1; + } + /* + * If we get an error during the commit processing, + * release the buffer that is still held and return + * to the caller. + */ + if (code) { + xfs_buf_relse(ialloc_context); + if (dqinfo) { + tp->t_dqinfo = dqinfo; + XFS_TRANS_FREE_DQINFO(tp->t_mountp, tp); + } + *tpp = ntp; + *ipp = NULL; + return code; + } + code = xfs_trans_reserve(tp, 0, log_res, 0, + XFS_TRANS_PERM_LOG_RES, log_count); + /* + * Re-attach the quota info that we detached from prev trx. + */ + if (dqinfo) { + tp->t_dqinfo = dqinfo; + tp->t_flags |= tflags; + } + + if (code) { + xfs_buf_relse(ialloc_context); + *tpp = ntp; + *ipp = NULL; + return code; + } + xfs_trans_bjoin(tp, ialloc_context); + + /* + * Call ialloc again. Since we've locked out all + * other allocations in this allocation group, + * this call should always succeed. + */ + code = xfs_ialloc(tp, dp, mode, nlink, rdev, credp, prid, + okalloc, &ialloc_context, &call_again, &ip); + + /* + * If we get an error at this point, return to the caller + * so that the current transaction can be aborted. + */ + if (code) { + *tpp = tp; + *ipp = NULL; + return code; + } + ASSERT ((!call_again) && (ip != NULL)); + + } else { + if (committed != NULL) { + *committed = 0; + } + } + + *ipp = ip; + *tpp = tp; + + return 0; +} + +/* + * Decrement the link count on an inode & log the change. + * If this causes the link count to go to zero, initiate the + * logging activity required to truncate a file. + */ +int /* error */ +xfs_droplink( + xfs_trans_t *tp, + xfs_inode_t *ip) +{ + int error; + + xfs_ichgtime(ip, XFS_ICHGTIME_CHG); + + ASSERT (ip->i_d.di_nlink > 0); + ip->i_d.di_nlink--; + xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); + + error = 0; + if (ip->i_d.di_nlink == 0) { + /* + * We're dropping the last link to this file. + * Move the on-disk inode to the AGI unlinked list. + * From xfs_inactive() we will pull the inode from + * the list and free it. + */ + error = xfs_iunlink(tp, ip); + } + return error; +} + +/* + * This gets called when the inode's version needs to be changed from 1 to 2. + * Currently this happens when the nlink field overflows the old 16-bit value + * or when chproj is called to change the project for the first time. + * As a side effect the superblock version will also get rev'd + * to contain the NLINK bit. + */ +void +xfs_bump_ino_vers2( + xfs_trans_t *tp, + xfs_inode_t *ip) +{ + xfs_mount_t *mp; + unsigned long s; + + ASSERT(ismrlocked (&ip->i_lock, MR_UPDATE)); + ASSERT(ip->i_d.di_version == XFS_DINODE_VERSION_1); + + ip->i_d.di_version = XFS_DINODE_VERSION_2; + ip->i_d.di_onlink = 0; + memset(&(ip->i_d.di_pad[0]), 0, sizeof(ip->i_d.di_pad)); + mp = tp->t_mountp; + if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) { + s = XFS_SB_LOCK(mp); + if (!XFS_SB_VERSION_HASNLINK(&mp->m_sb)) { + XFS_SB_VERSION_ADDNLINK(&mp->m_sb); + XFS_SB_UNLOCK(mp, s); + xfs_mod_sb(tp, XFS_SB_VERSIONNUM); + } else { + XFS_SB_UNLOCK(mp, s); + } + } + /* Caller must log the inode */ +} + +/* + * Increment the link count on an inode & log the change. + */ +int +xfs_bumplink( + xfs_trans_t *tp, + xfs_inode_t *ip) +{ + if (ip->i_d.di_nlink >= XFS_MAXLINK) + return XFS_ERROR(EMLINK); + xfs_ichgtime(ip, XFS_ICHGTIME_CHG); + + ASSERT(ip->i_d.di_nlink > 0); + ip->i_d.di_nlink++; + if ((ip->i_d.di_version == XFS_DINODE_VERSION_1) && + (ip->i_d.di_nlink > XFS_MAXLINK_1)) { + /* + * The inode has increased its number of links beyond + * what can fit in an old format inode. It now needs + * to be converted to a version 2 inode with a 32 bit + * link count. If this is the first inode in the file + * system to do this, then we need to bump the superblock + * version number as well. + */ + xfs_bump_ino_vers2(tp, ip); + } + + xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE); + return 0; +} + +/* + * Try to truncate the given file to 0 length. Currently called + * only out of xfs_remove when it has to truncate a file to free + * up space for the remove to proceed. + */ +int +xfs_truncate_file( + xfs_mount_t *mp, + xfs_inode_t *ip) +{ + xfs_trans_t *tp; + int error; + +#ifdef QUOTADEBUG + /* + * This is called to truncate the quotainodes too. + */ + if (XFS_IS_UQUOTA_ON(mp)) { + if (ip->i_ino != mp->m_sb.sb_uquotino) + ASSERT(ip->i_udquot); + } + if (XFS_IS_GQUOTA_ON(mp)) { + if (ip->i_ino != mp->m_sb.sb_gquotino) + ASSERT(ip->i_gdquot); + } +#endif + /* + * Make the call to xfs_itruncate_start before starting the + * transaction, because we cannot make the call while we're + * in a transaction. + */ + xfs_ilock(ip, XFS_IOLOCK_EXCL); + xfs_itruncate_start(ip, XFS_ITRUNC_DEFINITE, (xfs_fsize_t)0); + + tp = xfs_trans_alloc(mp, XFS_TRANS_TRUNCATE_FILE); + if ((error = xfs_trans_reserve(tp, 0, XFS_ITRUNCATE_LOG_RES(mp), 0, + XFS_TRANS_PERM_LOG_RES, + XFS_ITRUNCATE_LOG_COUNT))) { + xfs_trans_cancel(tp, 0); + xfs_iunlock(ip, XFS_IOLOCK_EXCL); + return error; + } + + /* + * Follow the normal truncate locking protocol. Since we + * hold the inode in the transaction, we know that it's number + * of references will stay constant. + */ + xfs_ilock(ip, XFS_ILOCK_EXCL); + xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); + xfs_trans_ihold(tp, ip); + /* + * Signal a sync xaction. The only case where that isn't + * the case is if we're truncating an already unlinked file + * on a wsync fs. In that case, we know the blocks can't + * reappear in the file because the links to file are + * permanently toast. Currently, we're always going to + * want a sync transaction because this code is being + * called from places where nlink is guaranteed to be 1 + * but I'm leaving the tests in to protect against future + * changes -- rcc. + */ + error = xfs_itruncate_finish(&tp, ip, (xfs_fsize_t)0, + XFS_DATA_FORK, + ((ip->i_d.di_nlink != 0 || + !(mp->m_flags & XFS_MOUNT_WSYNC)) + ? 1 : 0)); + if (error) { + xfs_trans_cancel(tp, XFS_TRANS_RELEASE_LOG_RES | + XFS_TRANS_ABORT); + } else { + xfs_ichgtime(ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG); + error = xfs_trans_commit(tp, XFS_TRANS_RELEASE_LOG_RES, + NULL); + } + xfs_iunlock(ip, XFS_ILOCK_EXCL | XFS_IOLOCK_EXCL); + + return error; +} |