cregit-Linux how code gets into the kernel

Release 4.11 fs/xfs/libxfs/xfs_attr_remote.c

Directory: fs/xfs/libxfs
/*
 * 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_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_bit.h"
#include "xfs_mount.h"
#include "xfs_defer.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_inode.h"
#include "xfs_alloc.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_bmap.h"
#include "xfs_bmap_util.h"
#include "xfs_attr.h"
#include "xfs_attr_leaf.h"
#include "xfs_attr_remote.h"
#include "xfs_trans_space.h"
#include "xfs_trace.h"
#include "xfs_cksum.h"
#include "xfs_buf_item.h"
#include "xfs_error.h"


#define ATTR_RMTVALUE_MAPSIZE	1	
/* # of map entries at once */

/*
 * Each contiguous block has a header, so it is not just a simple attribute
 * length to FSB conversion.
 */

int xfs_attr3_rmt_blocks( struct xfs_mount *mp, int attrlen) { if (xfs_sb_version_hascrc(&mp->m_sb)) { int buflen = XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize); return (attrlen + buflen - 1) / buflen; } return XFS_B_TO_FSB(mp, attrlen); }

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Dave Chinner58100.00%3100.00%
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/* * Checking of the remote attribute header is split into two parts. The verifier * does CRC, location and bounds checking, the unpacking function checks the * attribute parameters and owner. */
static bool xfs_attr3_rmt_hdr_ok( void *ptr, xfs_ino_t ino, uint32_t offset, uint32_t size, xfs_daddr_t bno) { struct xfs_attr3_rmt_hdr *rmt = ptr; if (bno != be64_to_cpu(rmt->rm_blkno)) return false; if (offset != be32_to_cpu(rmt->rm_offset)) return false; if (size != be32_to_cpu(rmt->rm_bytes)) return false; if (ino != be64_to_cpu(rmt->rm_owner)) return false; /* ok */ return true; }

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Dave Chinner89100.00%2100.00%
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static bool xfs_attr3_rmt_verify( struct xfs_mount *mp, void *ptr, int fsbsize, xfs_daddr_t bno) { struct xfs_attr3_rmt_hdr *rmt = ptr; if (!xfs_sb_version_hascrc(&mp->m_sb)) return false; if (rmt->rm_magic != cpu_to_be32(XFS_ATTR3_RMT_MAGIC)) return false; if (!uuid_equal(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid)) return false; if (be64_to_cpu(rmt->rm_blkno) != bno) return false; if (be32_to_cpu(rmt->rm_bytes) > fsbsize - sizeof(*rmt)) return false; if (be32_to_cpu(rmt->rm_offset) + be32_to_cpu(rmt->rm_bytes) > XFS_XATTR_SIZE_MAX) return false; if (rmt->rm_owner == 0) return false; return true; }

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Dave Chinner14397.95%240.00%
Eric Sandeen10.68%120.00%
Jie Liu10.68%120.00%
Jan Tulak10.68%120.00%
Total146100.00%5100.00%


static void xfs_attr3_rmt_read_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_target->bt_mount; char *ptr; int len; xfs_daddr_t bno; int blksize = mp->m_attr_geo->blksize; /* no verification of non-crc buffers */ if (!xfs_sb_version_hascrc(&mp->m_sb)) return; ptr = bp->b_addr; bno = bp->b_bn; len = BBTOB(bp->b_length); ASSERT(len >= blksize); while (len > 0) { if (!xfs_verify_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF)) { xfs_buf_ioerror(bp, -EFSBADCRC); break; } if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) { xfs_buf_ioerror(bp, -EFSCORRUPTED); break; } len -= blksize; ptr += blksize; bno += BTOBB(blksize); } if (bp->b_error) xfs_verifier_error(bp); else ASSERT(len == 0); }

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Dave Chinner15791.28%480.00%
Eric Sandeen158.72%120.00%
Total172100.00%5100.00%


static void xfs_attr3_rmt_write_verify( struct xfs_buf *bp) { struct xfs_mount *mp = bp->b_target->bt_mount; int blksize = mp->m_attr_geo->blksize; char *ptr; int len; xfs_daddr_t bno; /* no verification of non-crc buffers */ if (!xfs_sb_version_hascrc(&mp->m_sb)) return; ptr = bp->b_addr; bno = bp->b_bn; len = BBTOB(bp->b_length); ASSERT(len >= blksize); while (len > 0) { struct xfs_attr3_rmt_hdr *rmt = (struct xfs_attr3_rmt_hdr *)ptr; if (!xfs_attr3_rmt_verify(mp, ptr, blksize, bno)) { xfs_buf_ioerror(bp, -EFSCORRUPTED); xfs_verifier_error(bp); return; } /* * Ensure we aren't writing bogus LSNs to disk. See * xfs_attr3_rmt_hdr_set() for the explanation. */ if (rmt->rm_lsn != cpu_to_be64(NULLCOMMITLSN)) { xfs_buf_ioerror(bp, -EFSCORRUPTED); xfs_verifier_error(bp); return; } xfs_update_cksum(ptr, blksize, XFS_ATTR3_RMT_CRC_OFF); len -= blksize; ptr += blksize; bno += BTOBB(blksize); } ASSERT(len == 0); }

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Dave Chinner18797.91%583.33%
Eric Sandeen42.09%116.67%
Total191100.00%6100.00%

const struct xfs_buf_ops xfs_attr3_rmt_buf_ops = { .name = "xfs_attr3_rmt", .verify_read = xfs_attr3_rmt_read_verify, .verify_write = xfs_attr3_rmt_write_verify, };
STATIC int xfs_attr3_rmt_hdr_set( struct xfs_mount *mp, void *ptr, xfs_ino_t ino, uint32_t offset, uint32_t size, xfs_daddr_t bno) { struct xfs_attr3_rmt_hdr *rmt = ptr; if (!xfs_sb_version_hascrc(&mp->m_sb)) return 0; rmt->rm_magic = cpu_to_be32(XFS_ATTR3_RMT_MAGIC); rmt->rm_offset = cpu_to_be32(offset); rmt->rm_bytes = cpu_to_be32(size); uuid_copy(&rmt->rm_uuid, &mp->m_sb.sb_meta_uuid); rmt->rm_owner = cpu_to_be64(ino); rmt->rm_blkno = cpu_to_be64(bno); /* * Remote attribute blocks are written synchronously, so we don't * have an LSN that we can stamp in them that makes any sense to log * recovery. To ensure that log recovery handles overwrites of these * blocks sanely (i.e. once they've been freed and reallocated as some * other type of metadata) we need to ensure that the LSN has a value * that tells log recovery to ignore the LSN and overwrite the buffer * with whatever is in it's log. To do this, we use the magic * NULLCOMMITLSN to indicate that the LSN is invalid. */ rmt->rm_lsn = cpu_to_be64(NULLCOMMITLSN); return sizeof(struct xfs_attr3_rmt_hdr); }

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Dave Chinner12499.20%375.00%
Eric Sandeen10.80%125.00%
Total125100.00%4100.00%

/* * Helper functions to copy attribute data in and out of the one disk extents */
STATIC int xfs_attr_rmtval_copyout( struct xfs_mount *mp, struct xfs_buf *bp, xfs_ino_t ino, int *offset, int *valuelen, __uint8_t **dst) { char *src = bp->b_addr; xfs_daddr_t bno = bp->b_bn; int len = BBTOB(bp->b_length); int blksize = mp->m_attr_geo->blksize; ASSERT(len >= blksize); while (len > 0 && *valuelen > 0) { int hdr_size = 0; int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize); byte_cnt = min(*valuelen, byte_cnt); if (xfs_sb_version_hascrc(&mp->m_sb)) { if (!xfs_attr3_rmt_hdr_ok(src, ino, *offset, byte_cnt, bno)) { xfs_alert(mp, "remote attribute header mismatch bno/off/len/owner (0x%llx/0x%x/Ox%x/0x%llx)", bno, *offset, byte_cnt, ino); return -EFSCORRUPTED; } hdr_size = sizeof(struct xfs_attr3_rmt_hdr); } memcpy(*dst, src + hdr_size, byte_cnt); /* roll buffer forwards */ len -= blksize; src += blksize; bno += BTOBB(blksize); /* roll attribute data forwards */ *valuelen -= byte_cnt; *dst += byte_cnt; *offset += byte_cnt; } return 0; }

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Dave Chinner217100.00%6100.00%
Total217100.00%6100.00%


STATIC void xfs_attr_rmtval_copyin( struct xfs_mount *mp, struct xfs_buf *bp, xfs_ino_t ino, int *offset, int *valuelen, __uint8_t **src) { char *dst = bp->b_addr; xfs_daddr_t bno = bp->b_bn; int len = BBTOB(bp->b_length); int blksize = mp->m_attr_geo->blksize; ASSERT(len >= blksize); while (len > 0 && *valuelen > 0) { int hdr_size; int byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, blksize); byte_cnt = min(*valuelen, byte_cnt); hdr_size = xfs_attr3_rmt_hdr_set(mp, dst, ino, *offset, byte_cnt, bno); memcpy(dst + hdr_size, *src, byte_cnt); /* * If this is the last block, zero the remainder of it. * Check that we are actually the last block, too. */ if (byte_cnt + hdr_size < blksize) { ASSERT(*valuelen - byte_cnt == 0); ASSERT(len == blksize); memset(dst + hdr_size + byte_cnt, 0, blksize - hdr_size - byte_cnt); } /* roll buffer forwards */ len -= blksize; dst += blksize; bno += BTOBB(blksize); /* roll attribute data forwards */ *valuelen -= byte_cnt; *src += byte_cnt; *offset += byte_cnt; } }

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Dave Chinner216100.00%3100.00%
Total216100.00%3100.00%

/* * Read the value associated with an attribute from the out-of-line buffer * that we stored it in. */
int xfs_attr_rmtval_get( struct xfs_da_args *args) { struct xfs_bmbt_irec map[ATTR_RMTVALUE_MAPSIZE]; struct xfs_mount *mp = args->dp->i_mount; struct xfs_buf *bp; xfs_dablk_t lblkno = args->rmtblkno; __uint8_t *dst = args->value; int valuelen; int nmap; int error; int blkcnt = args->rmtblkcnt; int i; int offset = 0; trace_xfs_attr_rmtval_get(args); ASSERT(!(args->flags & ATTR_KERNOVAL)); ASSERT(args->rmtvaluelen == args->valuelen); valuelen = args->rmtvaluelen; while (valuelen > 0) { nmap = ATTR_RMTVALUE_MAPSIZE; error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno, blkcnt, map, &nmap, XFS_BMAPI_ATTRFORK); if (error) return error; ASSERT(nmap >= 1); for (i = 0; (i < nmap) && (valuelen > 0); i++) { xfs_daddr_t dblkno; int dblkcnt; ASSERT((map[i].br_startblock != DELAYSTARTBLOCK) && (map[i].br_startblock != HOLESTARTBLOCK)); dblkno = XFS_FSB_TO_DADDR(mp, map[i].br_startblock); dblkcnt = XFS_FSB_TO_BB(mp, map[i].br_blockcount); error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dblkno, dblkcnt, 0, &bp, &xfs_attr3_rmt_buf_ops); if (error) return error; error = xfs_attr_rmtval_copyout(mp, bp, args->dp->i_ino, &offset, &valuelen, &dst); xfs_buf_relse(bp); if (error) return error; /* roll attribute extent map forwards */ lblkno += map[i].br_blockcount; blkcnt -= map[i].br_blockcount; } } ASSERT(valuelen == 0); return 0; }

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Dave Chinner334100.00%6100.00%
Total334100.00%6100.00%

/* * Write the value associated with an attribute into the out-of-line buffer * that we have defined for it. */
int xfs_attr_rmtval_set( struct xfs_da_args *args) { struct xfs_inode *dp = args->dp; struct xfs_mount *mp = dp->i_mount; struct xfs_bmbt_irec map; xfs_dablk_t lblkno; xfs_fileoff_t lfileoff = 0; __uint8_t *src = args->value; int blkcnt; int valuelen; int nmap; int error; int offset = 0; trace_xfs_attr_rmtval_set(args); /* * Find a "hole" in the attribute address space large enough for * us to drop the new attribute's value into. Because CRC enable * attributes have headers, we can't just do a straight byte to FSB * conversion and have to take the header space into account. */ blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen); error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff, XFS_ATTR_FORK); if (error) return error; args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff; args->rmtblkcnt = blkcnt; /* * Roll through the "value", allocating blocks on disk as required. */ while (blkcnt > 0) { /* * Allocate a single extent, up to the size of the value. * * Note that we have to consider this a data allocation as we * write the remote attribute without logging the contents. * Hence we must ensure that we aren't using blocks that are on * the busy list so that we don't overwrite blocks which have * recently been freed but their transactions are not yet * committed to disk. If we overwrite the contents of a busy * extent and then crash then the block may not contain the * correct metadata after log recovery occurs. */ xfs_defer_init(args->dfops, args->firstblock); nmap = 1; error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno, blkcnt, XFS_BMAPI_ATTRFORK, args->firstblock, args->total, &map, &nmap, args->dfops); if (!error) error = xfs_defer_finish(&args->trans, args->dfops, dp); if (error) { args->trans = NULL; xfs_defer_cancel(args->dfops); return error; } ASSERT(nmap == 1); ASSERT((map.br_startblock != DELAYSTARTBLOCK) && (map.br_startblock != HOLESTARTBLOCK)); lblkno += map.br_blockcount; blkcnt -= map.br_blockcount; /* * Start the next trans in the chain. */ error = xfs_trans_roll(&args->trans, dp); if (error) return error; } /* * Roll through the "value", copying the attribute value to the * already-allocated blocks. Blocks are written synchronously * so that we can know they are all on disk before we turn off * the INCOMPLETE flag. */ lblkno = args->rmtblkno; blkcnt = args->rmtblkcnt; valuelen = args->rmtvaluelen; while (valuelen > 0) { struct xfs_buf *bp; xfs_daddr_t dblkno; int dblkcnt; ASSERT(blkcnt > 0); xfs_defer_init(args->dfops, args->firstblock); nmap = 1; error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno, blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK); if (error) return error; ASSERT(nmap == 1); ASSERT((map.br_startblock != DELAYSTARTBLOCK) && (map.br_startblock != HOLESTARTBLOCK)); dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock), dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount); bp = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, 0); if (!bp) return -ENOMEM; bp->b_ops = &xfs_attr3_rmt_buf_ops; xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset, &valuelen, &src); error = xfs_bwrite(bp); /* GROT: NOTE: synchronous write */ xfs_buf_relse(bp); if (error) return error; /* roll attribute extent map forwards */ lblkno += map.br_blockcount; blkcnt -= map.br_blockcount; } ASSERT(valuelen == 0); return 0; }

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Dave Chinner51398.09%872.73%
Darrick J. Wong91.72%218.18%
Eric Sandeen10.19%19.09%
Total523100.00%11100.00%

/* * Remove the value associated with an attribute by deleting the * out-of-line buffer that it is stored on. */
int xfs_attr_rmtval_remove( struct xfs_da_args *args) { struct xfs_mount *mp = args->dp->i_mount; xfs_dablk_t lblkno; int blkcnt; int error; int done; trace_xfs_attr_rmtval_remove(args); /* * Roll through the "value", invalidating the attribute value's blocks. */ lblkno = args->rmtblkno; blkcnt = args->rmtblkcnt; while (blkcnt > 0) { struct xfs_bmbt_irec map; struct xfs_buf *bp; xfs_daddr_t dblkno; int dblkcnt; int nmap; /* * Try to remember where we decided to put the value. */ nmap = 1; error = xfs_bmapi_read(args->dp, (xfs_fileoff_t)lblkno, blkcnt, &map, &nmap, XFS_BMAPI_ATTRFORK); if (error) return error; ASSERT(nmap == 1); ASSERT((map.br_startblock != DELAYSTARTBLOCK) && (map.br_startblock != HOLESTARTBLOCK)); dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock), dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount); /* * If the "remote" value is in the cache, remove it. */ bp = xfs_incore(mp->m_ddev_targp, dblkno, dblkcnt, XBF_TRYLOCK); if (bp) { xfs_buf_stale(bp); xfs_buf_relse(bp); bp = NULL; } lblkno += map.br_blockcount; blkcnt -= map.br_blockcount; } /* * Keep de-allocating extents until the remote-value region is gone. */ lblkno = args->rmtblkno; blkcnt = args->rmtblkcnt; done = 0; while (!done) { xfs_defer_init(args->dfops, args->firstblock); error = xfs_bunmapi(args->trans, args->dp, lblkno, blkcnt, XFS_BMAPI_ATTRFORK, 1, args->firstblock, args->dfops, &done); if (!error) error = xfs_defer_finish(&args->trans, args->dfops, args->dp); if (error) { args->trans = NULL; xfs_defer_cancel(args->dfops); return error; } /* * Close out trans and start the next one in the chain. */ error = xfs_trans_roll(&args->trans, args->dp); if (error) return error; } return 0; }

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Dave Chinner33697.11%457.14%
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Eric Sandeen30.87%114.29%
Total346100.00%7100.00%


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Dave Chinner247597.98%2068.97%
Eric Sandeen301.19%413.79%
Darrick J. Wong190.75%310.34%
Jan Tulak10.04%13.45%
Jie Liu10.04%13.45%
Total2526100.00%29100.00%
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