/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*- * vim:expandtab:shiftwidth=8:tabstop=8: * * lustre/lib/fsfilt_ext3.c * Lustre filesystem abstraction routines * * Copyright (C) 2002, 2003 Cluster File Systems, Inc. * Author: Andreas Dilger * * This file is part of Lustre, http://www.lustre.org. * * Lustre 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. * * Lustre is distributed in the hope that it will 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 Lustre; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ #define DEBUG_SUBSYSTEM S_FILTER #include #include #include #include #include #include #include #include #include #include #include #include #include static kmem_cache_t *fcb_cache; static atomic_t fcb_cache_count = ATOMIC_INIT(0); struct fsfilt_cb_data { struct journal_callback cb_jcb; /* data private to jbd */ fsfilt_cb_t cb_func; /* MDS/OBD completion function */ struct obd_device *cb_obd; /* MDS/OBD completion device */ __u64 cb_last_rcvd; /* MDS/OST last committed operation */ }; #define EXT3_XATTR_INDEX_LUSTRE 5 #define XATTR_LUSTRE_MDS_OBJID "system.lustre_mds_objid" /* * We don't currently need any additional blocks for rmdir and * unlink transactions because we are storing the OST oa_id inside * the inode (which we will be changing anyways as part of this * transaction). */ static void *fsfilt_ext3_start(struct inode *inode, int op) { /* For updates to the last recieved file */ int nblocks = EXT3_DATA_TRANS_BLOCKS; void *handle; switch(op) { case FSFILT_OP_RMDIR: case FSFILT_OP_UNLINK: nblocks += EXT3_DELETE_TRANS_BLOCKS; break; case FSFILT_OP_RENAME: /* modify additional directory */ nblocks += EXT3_DATA_TRANS_BLOCKS; /* no break */ case FSFILT_OP_SYMLINK: /* additional block + block bitmap + GDT for long symlink */ nblocks += 3; /* no break */ case FSFILT_OP_CREATE: case FSFILT_OP_MKDIR: case FSFILT_OP_MKNOD: /* modify one inode + block bitmap + GDT */ nblocks += 3; /* no break */ case FSFILT_OP_LINK: /* modify parent directory */ nblocks += EXT3_INDEX_EXTRA_TRANS_BLOCKS+EXT3_DATA_TRANS_BLOCKS; break; case FSFILT_OP_SETATTR: /* Setattr on inode */ nblocks += 1; break; default: CERROR("unknown transaction start op %d\n", op); LBUG(); } LASSERT(!current->journal_info); lock_kernel(); handle = journal_start(EXT3_JOURNAL(inode), nblocks); unlock_kernel(); return handle; } /* * Calculate the number of buffer credits needed to write multiple pages in * a single ext3 transaction. No, this shouldn't be here, but as yet ext3 * doesn't have a nice API for calculating this sort of thing in advance. * * See comment above ext3_writepage_trans_blocks for details. We assume * no data journaling is being done, but it does allow for all of the pages * being non-contiguous. If we are guaranteed contiguous pages we could * reduce the number of (d)indirect blocks a lot. * * With N blocks per page and P pages, for each inode we have at most: * N*P indirect * min(N*P, blocksize/4 + 1) dindirect blocks * niocount tindirect * * For the entire filesystem, we have at most: * min(sum(nindir + P), ngroups) bitmap blocks (from the above) * min(sum(nindir + P), gdblocks) group descriptor blocks (from the above) * objcount inode blocks * 1 superblock * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quota files * * 1 EXT3_DATA_TRANS_BLOCKS for the last_rcvd update. */ static int fsfilt_ext3_credits_needed(int objcount, struct fsfilt_objinfo *fso) { struct super_block *sb = fso->fso_dentry->d_inode->i_sb; int blockpp = 1 << (PAGE_CACHE_SHIFT - sb->s_blocksize_bits); int addrpp = EXT3_ADDR_PER_BLOCK(sb) * blockpp; int nbitmaps = 0; int ngdblocks = 0; int needed = objcount + 1; int i; for (i = 0; i < objcount; i++, fso++) { int nblocks = fso->fso_bufcnt * blockpp; int ndindirect = min(nblocks, addrpp + 1); int nindir = nblocks + ndindirect + 1; nbitmaps += nindir + nblocks; ngdblocks += nindir + nblocks; needed += nindir; } /* Assumes ext3 and ext3 have same sb_info layout at the start. */ if (nbitmaps > EXT3_SB(sb)->s_groups_count) nbitmaps = EXT3_SB(sb)->s_groups_count; if (ngdblocks > EXT3_SB(sb)->s_gdb_count) ngdblocks = EXT3_SB(sb)->s_gdb_count; needed += nbitmaps + ngdblocks; /* last_rcvd update */ needed += EXT3_DATA_TRANS_BLOCKS; #ifdef CONFIG_QUOTA /* We assume that there will be 1 bit set in s_dquot.flags for each * quota file that is active. This is at least true for now. */ needed += hweight32(sb_any_quota_enabled(sb)) * EXT3_SINGLEDATA_TRANS_BLOCKS; #endif return needed; } /* We have to start a huge journal transaction here to hold all of the * metadata for the pages being written here. This is necessitated by * the fact that we do lots of prepare_write operations before we do * any of the matching commit_write operations, so even if we split * up to use "smaller" transactions none of them could complete until * all of them were opened. By having a single journal transaction, * we eliminate duplicate reservations for common blocks like the * superblock and group descriptors or bitmaps. * * We will start the transaction here, but each prepare_write will * add a refcount to the transaction, and each commit_write will * remove a refcount. The transaction will be closed when all of * the pages have been written. */ static void *fsfilt_ext3_brw_start(int objcount, struct fsfilt_objinfo *fso, int niocount, struct niobuf_remote *nb) { journal_t *journal; handle_t *handle; int needed; ENTRY; LASSERT(!current->journal_info); journal = EXT3_SB(fso->fso_dentry->d_inode->i_sb)->s_journal; needed = fsfilt_ext3_credits_needed(objcount, fso); /* The number of blocks we could _possibly_ dirty can very large. * We reduce our request if it is absurd (and we couldn't get that * many credits for a single handle anyways). * * At some point we have to limit the size of I/Os sent at one time, * increase the size of the journal, or we have to calculate the * actual journal requirements more carefully by checking all of * the blocks instead of being maximally pessimistic. It remains to * be seen if this is a real problem or not. */ if (needed > journal->j_max_transaction_buffers) { CERROR("want too many journal credits (%d) using %d instead\n", needed, journal->j_max_transaction_buffers); needed = journal->j_max_transaction_buffers; } lock_kernel(); handle = journal_start(journal, needed); unlock_kernel(); if (IS_ERR(handle)) CERROR("can't get handle for %d credits: rc = %ld\n", needed, PTR_ERR(handle)); RETURN(handle); } static int fsfilt_ext3_commit(struct inode *inode, void *h, int force_sync) { int rc; handle_t *handle = h; if (force_sync) handle->h_sync = 1; /* recovery likes this */ lock_kernel(); rc = journal_stop(handle); unlock_kernel(); return rc; } static int fsfilt_ext3_setattr(struct dentry *dentry, void *handle, struct iattr *iattr, int do_trunc) { struct inode *inode = dentry->d_inode; int rc; lock_kernel(); /* A _really_ horrible hack to avoid removing the data stored * in the block pointers; this is really the "small" stripe MD data. * We can avoid further hackery by virtue of the MDS file size being * zero all the time (which doesn't invoke block truncate at unlink * time), so we assert we never change the MDS file size from zero. */ if (iattr->ia_valid & ATTR_SIZE && !do_trunc) { /* ATTR_SIZE would invoke truncate: clear it */ iattr->ia_valid &= ~ATTR_SIZE; inode->i_size = iattr->ia_size; /* make sure _something_ gets set - so new inode * goes to disk (probably won't work over XFS */ if (!iattr->ia_valid & ATTR_MODE) { iattr->ia_valid |= ATTR_MODE; iattr->ia_mode = inode->i_mode; } } if (inode->i_op->setattr) rc = inode->i_op->setattr(dentry, iattr); else{ rc = inode_change_ok(inode, iattr); if (!rc) rc = inode_setattr(inode, iattr); } unlock_kernel(); return rc; } static int fsfilt_ext3_set_md(struct inode *inode, void *handle, void *lmm, int lmm_size) { int rc; /* Nasty hack city - store stripe MD data in the block pointers if * it will fit, because putting it in an EA currently kills the MDS * performance. We'll fix this with "fast EAs" in the future. */ if (lmm_size <= sizeof(EXT3_I(inode)->i_data) - sizeof(EXT3_I(inode)->i_data[0])) { /* XXX old_size is debugging only */ int old_size = EXT3_I(inode)->i_data[0]; if (old_size != 0) { LASSERT(old_size < sizeof(EXT3_I(inode)->i_data)); CERROR("setting EA on %lu again... interesting\n", inode->i_ino); } EXT3_I(inode)->i_data[0] = cpu_to_le32(lmm_size); memcpy(&EXT3_I(inode)->i_data[1], lmm, lmm_size); mark_inode_dirty(inode); return 0; } else { down(&inode->i_sem); lock_kernel(); rc = ext3_xattr_set(handle, inode, EXT3_XATTR_INDEX_LUSTRE, XATTR_LUSTRE_MDS_OBJID, lmm, lmm_size, 0); unlock_kernel(); up(&inode->i_sem); } if (rc) CERROR("error adding MD data to inode %lu: rc = %d\n", inode->i_ino, rc); return rc; } static int fsfilt_ext3_get_md(struct inode *inode, void *lmm, int lmm_size) { int rc; if (EXT3_I(inode)->i_data[0]) { int size = le32_to_cpu(EXT3_I(inode)->i_data[0]); LASSERT(size < sizeof(EXT3_I(inode)->i_data)); if (lmm) { if (size > lmm_size) return -ERANGE; memcpy(lmm, &EXT3_I(inode)->i_data[1], size); } return size; } down(&inode->i_sem); lock_kernel(); rc = ext3_xattr_get(inode, EXT3_XATTR_INDEX_LUSTRE, XATTR_LUSTRE_MDS_OBJID, lmm, lmm_size); unlock_kernel(); up(&inode->i_sem); /* This gives us the MD size */ if (lmm == NULL) return (rc == -ENODATA) ? 0 : rc; if (rc < 0) { CDEBUG(D_INFO, "error getting EA %s from inode %lu: " "rc = %d\n", XATTR_LUSTRE_MDS_OBJID, inode->i_ino, rc); memset(lmm, 0, lmm_size); return (rc == -ENODATA) ? 0 : rc; } return rc; } static ssize_t fsfilt_ext3_readpage(struct file *file, char *buf, size_t count, loff_t *off) { struct inode *inode = file->f_dentry->d_inode; int rc = 0; if (S_ISREG(inode->i_mode)) rc = file->f_op->read(file, buf, count, off); else { const int blkbits = inode->i_sb->s_blocksize_bits; const int blksize = inode->i_sb->s_blocksize; CDEBUG(D_EXT2, "reading "LPSZ" at dir %lu+%llu\n", count, inode->i_ino, *off); while (count > 0) { struct buffer_head *bh; bh = NULL; if (*off < inode->i_size) { int err = 0; bh = ext3_bread(NULL, inode, *off >> blkbits, 0, &err); CDEBUG(D_EXT2, "read %u@%llu\n", blksize, *off); if (bh) { memcpy(buf, bh->b_data, blksize); brelse(bh); } else if (err) { /* XXX in theory we should just fake * this buffer and continue like ext3, * especially if this is a partial read */ CERROR("error read dir %lu+%llu: %d\n", inode->i_ino, *off, err); RETURN(err); } } if (!bh) { struct ext3_dir_entry_2 *fake = (void *)buf; CDEBUG(D_EXT2, "fake %u@%llu\n", blksize, *off); memset(fake, 0, sizeof(*fake)); fake->rec_len = cpu_to_le32(blksize); } count -= blksize; buf += blksize; *off += blksize; rc += blksize; } } return rc; } static void fsfilt_ext3_cb_func(struct journal_callback *jcb, int error) { struct fsfilt_cb_data *fcb = (struct fsfilt_cb_data *)jcb; fcb->cb_func(fcb->cb_obd, fcb->cb_last_rcvd, error); OBD_SLAB_FREE(fcb, fcb_cache, sizeof *fcb); atomic_dec(&fcb_cache_count); } static int fsfilt_ext3_set_last_rcvd(struct obd_device *obd, __u64 last_rcvd, void *handle, fsfilt_cb_t cb_func) { struct fsfilt_cb_data *fcb; OBD_SLAB_ALLOC(fcb, fcb_cache, GFP_NOFS, sizeof *fcb); if (fcb == NULL) RETURN(-ENOMEM); atomic_inc(&fcb_cache_count); fcb->cb_func = cb_func; fcb->cb_obd = obd; fcb->cb_last_rcvd = last_rcvd; CDEBUG(D_EXT2, "set callback for last_rcvd: "LPD64"\n", last_rcvd); lock_kernel(); /* Note that an "incompatible pointer" warning here is OK for now */ journal_callback_set(handle, fsfilt_ext3_cb_func, (struct journal_callback *)fcb); unlock_kernel(); return 0; } static int fsfilt_ext3_journal_data(struct file *filp) { struct inode *inode = filp->f_dentry->d_inode; EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL; return 0; } /* * We need to hack the return value for the free inode counts because * the current EA code requires one filesystem block per inode with EAs, * so it is possible to run out of blocks before we run out of inodes. * * This can be removed when the ext3 EA code is fixed. */ static int fsfilt_ext3_statfs(struct super_block *sb, struct obd_statfs *osfs) { struct statfs sfs; int rc = vfs_statfs(sb, &sfs); if (!rc && sfs.f_bfree < sfs.f_ffree) { sfs.f_files = (sfs.f_files - sfs.f_ffree) + sfs.f_bfree; sfs.f_ffree = sfs.f_bfree; } statfs_pack(osfs, &sfs); return rc; } static int fsfilt_ext3_sync(struct super_block *sb) { return ext3_force_commit(sb); } extern int ext3_prep_san_write(struct inode *inode, long *blocks, int nblocks, loff_t newsize); static int fsfilt_ext3_prep_san_write(struct inode *inode, long *blocks, int nblocks, loff_t newsize) { return ext3_prep_san_write(inode, blocks, nblocks, newsize); } static struct fsfilt_operations fsfilt_ext3_ops = { fs_type: "ext3", fs_owner: THIS_MODULE, fs_start: fsfilt_ext3_start, fs_brw_start: fsfilt_ext3_brw_start, fs_commit: fsfilt_ext3_commit, fs_setattr: fsfilt_ext3_setattr, fs_set_md: fsfilt_ext3_set_md, fs_get_md: fsfilt_ext3_get_md, fs_readpage: fsfilt_ext3_readpage, fs_journal_data: fsfilt_ext3_journal_data, fs_set_last_rcvd: fsfilt_ext3_set_last_rcvd, fs_statfs: fsfilt_ext3_statfs, fs_sync: fsfilt_ext3_sync, fs_prep_san_write: fsfilt_ext3_prep_san_write, }; static int __init fsfilt_ext3_init(void) { int rc; //rc = ext3_xattr_register(); fcb_cache = kmem_cache_create("fsfilt_ext3_fcb", sizeof(struct fsfilt_cb_data), 0, 0, NULL, NULL); if (!fcb_cache) { CERROR("error allocating fsfilt journal callback cache\n"); GOTO(out, rc = -ENOMEM); } rc = fsfilt_register_ops(&fsfilt_ext3_ops); if (rc) kmem_cache_destroy(fcb_cache); out: return rc; } static void __exit fsfilt_ext3_exit(void) { int rc; fsfilt_unregister_ops(&fsfilt_ext3_ops); rc = kmem_cache_destroy(fcb_cache); if (rc || atomic_read(&fcb_cache_count)) { CERROR("can't free fsfilt callback cache: count %d, rc = %d\n", atomic_read(&fcb_cache_count), rc); } //rc = ext3_xattr_unregister(); } MODULE_AUTHOR("Cluster File Systems, Inc. "); MODULE_DESCRIPTION("Lustre ext3 Filesystem Helper v0.1"); MODULE_LICENSE("GPL"); module_init(fsfilt_ext3_init); module_exit(fsfilt_ext3_exit);