diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_dir2.c')
| -rw-r--r-- | fs/xfs/libxfs/xfs_dir2.c | 769 |
1 files changed, 769 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_dir2.c b/fs/xfs/libxfs/xfs_dir2.c new file mode 100644 index 000000000..92bac3373 --- /dev/null +++ b/fs/xfs/libxfs/xfs_dir2.c @@ -0,0 +1,769 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#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_mount.h" +#include "xfs_inode.h" +#include "xfs_trans.h" +#include "xfs_bmap.h" +#include "xfs_dir2.h" +#include "xfs_dir2_priv.h" +#include "xfs_errortag.h" +#include "xfs_error.h" +#include "xfs_trace.h" + +const struct xfs_name xfs_name_dotdot = { + .name = (const unsigned char *)"..", + .len = 2, + .type = XFS_DIR3_FT_DIR, +}; + +/* + * Convert inode mode to directory entry filetype + */ +unsigned char +xfs_mode_to_ftype( + int mode) +{ + switch (mode & S_IFMT) { + case S_IFREG: + return XFS_DIR3_FT_REG_FILE; + case S_IFDIR: + return XFS_DIR3_FT_DIR; + case S_IFCHR: + return XFS_DIR3_FT_CHRDEV; + case S_IFBLK: + return XFS_DIR3_FT_BLKDEV; + case S_IFIFO: + return XFS_DIR3_FT_FIFO; + case S_IFSOCK: + return XFS_DIR3_FT_SOCK; + case S_IFLNK: + return XFS_DIR3_FT_SYMLINK; + default: + return XFS_DIR3_FT_UNKNOWN; + } +} + +/* + * ASCII case-insensitive (ie. A-Z) support for directories that was + * used in IRIX. + */ +xfs_dahash_t +xfs_ascii_ci_hashname( + const struct xfs_name *name) +{ + xfs_dahash_t hash; + int i; + + for (i = 0, hash = 0; i < name->len; i++) + hash = tolower(name->name[i]) ^ rol32(hash, 7); + + return hash; +} + +enum xfs_dacmp +xfs_ascii_ci_compname( + struct xfs_da_args *args, + const unsigned char *name, + int len) +{ + enum xfs_dacmp result; + int i; + + if (args->namelen != len) + return XFS_CMP_DIFFERENT; + + result = XFS_CMP_EXACT; + for (i = 0; i < len; i++) { + if (args->name[i] == name[i]) + continue; + if (tolower(args->name[i]) != tolower(name[i])) + return XFS_CMP_DIFFERENT; + result = XFS_CMP_CASE; + } + + return result; +} + +int +xfs_da_mount( + struct xfs_mount *mp) +{ + struct xfs_da_geometry *dageo; + + + ASSERT(mp->m_sb.sb_versionnum & XFS_SB_VERSION_DIRV2BIT); + ASSERT(xfs_dir2_dirblock_bytes(&mp->m_sb) <= XFS_MAX_BLOCKSIZE); + + mp->m_dir_geo = kmem_zalloc(sizeof(struct xfs_da_geometry), + KM_MAYFAIL); + mp->m_attr_geo = kmem_zalloc(sizeof(struct xfs_da_geometry), + KM_MAYFAIL); + if (!mp->m_dir_geo || !mp->m_attr_geo) { + kmem_free(mp->m_dir_geo); + kmem_free(mp->m_attr_geo); + return -ENOMEM; + } + + /* set up directory geometry */ + dageo = mp->m_dir_geo; + dageo->blklog = mp->m_sb.sb_blocklog + mp->m_sb.sb_dirblklog; + dageo->fsblog = mp->m_sb.sb_blocklog; + dageo->blksize = xfs_dir2_dirblock_bytes(&mp->m_sb); + dageo->fsbcount = 1 << mp->m_sb.sb_dirblklog; + if (xfs_has_crc(mp)) { + dageo->node_hdr_size = sizeof(struct xfs_da3_node_hdr); + dageo->leaf_hdr_size = sizeof(struct xfs_dir3_leaf_hdr); + dageo->free_hdr_size = sizeof(struct xfs_dir3_free_hdr); + dageo->data_entry_offset = + sizeof(struct xfs_dir3_data_hdr); + } else { + dageo->node_hdr_size = sizeof(struct xfs_da_node_hdr); + dageo->leaf_hdr_size = sizeof(struct xfs_dir2_leaf_hdr); + dageo->free_hdr_size = sizeof(struct xfs_dir2_free_hdr); + dageo->data_entry_offset = + sizeof(struct xfs_dir2_data_hdr); + } + dageo->leaf_max_ents = (dageo->blksize - dageo->leaf_hdr_size) / + sizeof(struct xfs_dir2_leaf_entry); + dageo->free_max_bests = (dageo->blksize - dageo->free_hdr_size) / + sizeof(xfs_dir2_data_off_t); + + dageo->data_first_offset = dageo->data_entry_offset + + xfs_dir2_data_entsize(mp, 1) + + xfs_dir2_data_entsize(mp, 2); + + /* + * Now we've set up the block conversion variables, we can calculate the + * segment block constants using the geometry structure. + */ + dageo->datablk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_DATA_OFFSET); + dageo->leafblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_LEAF_OFFSET); + dageo->freeblk = xfs_dir2_byte_to_da(dageo, XFS_DIR2_FREE_OFFSET); + dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) / + (uint)sizeof(xfs_da_node_entry_t); + dageo->max_extents = (XFS_DIR2_MAX_SPACES * XFS_DIR2_SPACE_SIZE) >> + mp->m_sb.sb_blocklog; + dageo->magicpct = (dageo->blksize * 37) / 100; + + /* set up attribute geometry - single fsb only */ + dageo = mp->m_attr_geo; + dageo->blklog = mp->m_sb.sb_blocklog; + dageo->fsblog = mp->m_sb.sb_blocklog; + dageo->blksize = 1 << dageo->blklog; + dageo->fsbcount = 1; + dageo->node_hdr_size = mp->m_dir_geo->node_hdr_size; + dageo->node_ents = (dageo->blksize - dageo->node_hdr_size) / + (uint)sizeof(xfs_da_node_entry_t); + + if (xfs_has_large_extent_counts(mp)) + dageo->max_extents = XFS_MAX_EXTCNT_ATTR_FORK_LARGE; + else + dageo->max_extents = XFS_MAX_EXTCNT_ATTR_FORK_SMALL; + + dageo->magicpct = (dageo->blksize * 37) / 100; + return 0; +} + +void +xfs_da_unmount( + struct xfs_mount *mp) +{ + kmem_free(mp->m_dir_geo); + kmem_free(mp->m_attr_geo); +} + +/* + * Return 1 if directory contains only "." and "..". + */ +int +xfs_dir_isempty( + xfs_inode_t *dp) +{ + xfs_dir2_sf_hdr_t *sfp; + + ASSERT(S_ISDIR(VFS_I(dp)->i_mode)); + if (dp->i_disk_size == 0) /* might happen during shutdown. */ + return 1; + if (dp->i_disk_size > xfs_inode_data_fork_size(dp)) + return 0; + sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data; + return !sfp->count; +} + +/* + * Validate a given inode number. + */ +int +xfs_dir_ino_validate( + xfs_mount_t *mp, + xfs_ino_t ino) +{ + bool ino_ok = xfs_verify_dir_ino(mp, ino); + + if (XFS_IS_CORRUPT(mp, !ino_ok) || + XFS_TEST_ERROR(false, mp, XFS_ERRTAG_DIR_INO_VALIDATE)) { + xfs_warn(mp, "Invalid inode number 0x%Lx", + (unsigned long long) ino); + return -EFSCORRUPTED; + } + return 0; +} + +/* + * Initialize a directory with its "." and ".." entries. + */ +int +xfs_dir_init( + xfs_trans_t *tp, + xfs_inode_t *dp, + xfs_inode_t *pdp) +{ + struct xfs_da_args *args; + int error; + + ASSERT(S_ISDIR(VFS_I(dp)->i_mode)); + error = xfs_dir_ino_validate(tp->t_mountp, pdp->i_ino); + if (error) + return error; + + args = kmem_zalloc(sizeof(*args), KM_NOFS); + if (!args) + return -ENOMEM; + + args->geo = dp->i_mount->m_dir_geo; + args->dp = dp; + args->trans = tp; + error = xfs_dir2_sf_create(args, pdp->i_ino); + kmem_free(args); + return error; +} + +/* + * Enter a name in a directory, or check for available space. + * If inum is 0, only the available space test is performed. + */ +int +xfs_dir_createname( + struct xfs_trans *tp, + struct xfs_inode *dp, + const struct xfs_name *name, + xfs_ino_t inum, /* new entry inode number */ + xfs_extlen_t total) /* bmap's total block count */ +{ + struct xfs_da_args *args; + int rval; + bool v; + + ASSERT(S_ISDIR(VFS_I(dp)->i_mode)); + + if (inum) { + rval = xfs_dir_ino_validate(tp->t_mountp, inum); + if (rval) + return rval; + XFS_STATS_INC(dp->i_mount, xs_dir_create); + } + + args = kmem_zalloc(sizeof(*args), KM_NOFS); + if (!args) + return -ENOMEM; + + args->geo = dp->i_mount->m_dir_geo; + args->name = name->name; + args->namelen = name->len; + args->filetype = name->type; + args->hashval = xfs_dir2_hashname(dp->i_mount, name); + args->inumber = inum; + args->dp = dp; + args->total = total; + args->whichfork = XFS_DATA_FORK; + args->trans = tp; + args->op_flags = XFS_DA_OP_ADDNAME | XFS_DA_OP_OKNOENT; + if (!inum) + args->op_flags |= XFS_DA_OP_JUSTCHECK; + + if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) { + rval = xfs_dir2_sf_addname(args); + goto out_free; + } + + rval = xfs_dir2_isblock(args, &v); + if (rval) + goto out_free; + if (v) { + rval = xfs_dir2_block_addname(args); + goto out_free; + } + + rval = xfs_dir2_isleaf(args, &v); + if (rval) + goto out_free; + if (v) + rval = xfs_dir2_leaf_addname(args); + else + rval = xfs_dir2_node_addname(args); + +out_free: + kmem_free(args); + return rval; +} + +/* + * If doing a CI lookup and case-insensitive match, dup actual name into + * args.value. Return EEXIST for success (ie. name found) or an error. + */ +int +xfs_dir_cilookup_result( + struct xfs_da_args *args, + const unsigned char *name, + int len) +{ + if (args->cmpresult == XFS_CMP_DIFFERENT) + return -ENOENT; + if (args->cmpresult != XFS_CMP_CASE || + !(args->op_flags & XFS_DA_OP_CILOOKUP)) + return -EEXIST; + + args->value = kmem_alloc(len, KM_NOFS | KM_MAYFAIL); + if (!args->value) + return -ENOMEM; + + memcpy(args->value, name, len); + args->valuelen = len; + return -EEXIST; +} + +/* + * Lookup a name in a directory, give back the inode number. + * If ci_name is not NULL, returns the actual name in ci_name if it differs + * to name, or ci_name->name is set to NULL for an exact match. + */ + +int +xfs_dir_lookup( + struct xfs_trans *tp, + struct xfs_inode *dp, + const struct xfs_name *name, + xfs_ino_t *inum, /* out: inode number */ + struct xfs_name *ci_name) /* out: actual name if CI match */ +{ + struct xfs_da_args *args; + int rval; + bool v; + int lock_mode; + + ASSERT(S_ISDIR(VFS_I(dp)->i_mode)); + XFS_STATS_INC(dp->i_mount, xs_dir_lookup); + + /* + * We need to use KM_NOFS here so that lockdep will not throw false + * positive deadlock warnings on a non-transactional lookup path. It is + * safe to recurse into inode recalim in that case, but lockdep can't + * easily be taught about it. Hence KM_NOFS avoids having to add more + * lockdep Doing this avoids having to add a bunch of lockdep class + * annotations into the reclaim path for the ilock. + */ + args = kmem_zalloc(sizeof(*args), KM_NOFS); + args->geo = dp->i_mount->m_dir_geo; + args->name = name->name; + args->namelen = name->len; + args->filetype = name->type; + args->hashval = xfs_dir2_hashname(dp->i_mount, name); + args->dp = dp; + args->whichfork = XFS_DATA_FORK; + args->trans = tp; + args->op_flags = XFS_DA_OP_OKNOENT; + if (ci_name) + args->op_flags |= XFS_DA_OP_CILOOKUP; + + lock_mode = xfs_ilock_data_map_shared(dp); + if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) { + rval = xfs_dir2_sf_lookup(args); + goto out_check_rval; + } + + rval = xfs_dir2_isblock(args, &v); + if (rval) + goto out_free; + if (v) { + rval = xfs_dir2_block_lookup(args); + goto out_check_rval; + } + + rval = xfs_dir2_isleaf(args, &v); + if (rval) + goto out_free; + if (v) + rval = xfs_dir2_leaf_lookup(args); + else + rval = xfs_dir2_node_lookup(args); + +out_check_rval: + if (rval == -EEXIST) + rval = 0; + if (!rval) { + *inum = args->inumber; + if (ci_name) { + ci_name->name = args->value; + ci_name->len = args->valuelen; + } + } +out_free: + xfs_iunlock(dp, lock_mode); + kmem_free(args); + return rval; +} + +/* + * Remove an entry from a directory. + */ +int +xfs_dir_removename( + struct xfs_trans *tp, + struct xfs_inode *dp, + struct xfs_name *name, + xfs_ino_t ino, + xfs_extlen_t total) /* bmap's total block count */ +{ + struct xfs_da_args *args; + int rval; + bool v; + + ASSERT(S_ISDIR(VFS_I(dp)->i_mode)); + XFS_STATS_INC(dp->i_mount, xs_dir_remove); + + args = kmem_zalloc(sizeof(*args), KM_NOFS); + if (!args) + return -ENOMEM; + + args->geo = dp->i_mount->m_dir_geo; + args->name = name->name; + args->namelen = name->len; + args->filetype = name->type; + args->hashval = xfs_dir2_hashname(dp->i_mount, name); + args->inumber = ino; + args->dp = dp; + args->total = total; + args->whichfork = XFS_DATA_FORK; + args->trans = tp; + + if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) { + rval = xfs_dir2_sf_removename(args); + goto out_free; + } + + rval = xfs_dir2_isblock(args, &v); + if (rval) + goto out_free; + if (v) { + rval = xfs_dir2_block_removename(args); + goto out_free; + } + + rval = xfs_dir2_isleaf(args, &v); + if (rval) + goto out_free; + if (v) + rval = xfs_dir2_leaf_removename(args); + else + rval = xfs_dir2_node_removename(args); +out_free: + kmem_free(args); + return rval; +} + +/* + * Replace the inode number of a directory entry. + */ +int +xfs_dir_replace( + struct xfs_trans *tp, + struct xfs_inode *dp, + const struct xfs_name *name, /* name of entry to replace */ + xfs_ino_t inum, /* new inode number */ + xfs_extlen_t total) /* bmap's total block count */ +{ + struct xfs_da_args *args; + int rval; + bool v; + + ASSERT(S_ISDIR(VFS_I(dp)->i_mode)); + + rval = xfs_dir_ino_validate(tp->t_mountp, inum); + if (rval) + return rval; + + args = kmem_zalloc(sizeof(*args), KM_NOFS); + if (!args) + return -ENOMEM; + + args->geo = dp->i_mount->m_dir_geo; + args->name = name->name; + args->namelen = name->len; + args->filetype = name->type; + args->hashval = xfs_dir2_hashname(dp->i_mount, name); + args->inumber = inum; + args->dp = dp; + args->total = total; + args->whichfork = XFS_DATA_FORK; + args->trans = tp; + + if (dp->i_df.if_format == XFS_DINODE_FMT_LOCAL) { + rval = xfs_dir2_sf_replace(args); + goto out_free; + } + + rval = xfs_dir2_isblock(args, &v); + if (rval) + goto out_free; + if (v) { + rval = xfs_dir2_block_replace(args); + goto out_free; + } + + rval = xfs_dir2_isleaf(args, &v); + if (rval) + goto out_free; + if (v) + rval = xfs_dir2_leaf_replace(args); + else + rval = xfs_dir2_node_replace(args); +out_free: + kmem_free(args); + return rval; +} + +/* + * See if this entry can be added to the directory without allocating space. + */ +int +xfs_dir_canenter( + xfs_trans_t *tp, + xfs_inode_t *dp, + struct xfs_name *name) /* name of entry to add */ +{ + return xfs_dir_createname(tp, dp, name, 0, 0); +} + +/* + * Utility routines. + */ + +/* + * Add a block to the directory. + * + * This routine is for data and free blocks, not leaf/node blocks which are + * handled by xfs_da_grow_inode. + */ +int +xfs_dir2_grow_inode( + struct xfs_da_args *args, + int space, /* v2 dir's space XFS_DIR2_xxx_SPACE */ + xfs_dir2_db_t *dbp) /* out: block number added */ +{ + struct xfs_inode *dp = args->dp; + struct xfs_mount *mp = dp->i_mount; + xfs_fileoff_t bno; /* directory offset of new block */ + int count; /* count of filesystem blocks */ + int error; + + trace_xfs_dir2_grow_inode(args, space); + + /* + * Set lowest possible block in the space requested. + */ + bno = XFS_B_TO_FSBT(mp, space * XFS_DIR2_SPACE_SIZE); + count = args->geo->fsbcount; + + error = xfs_da_grow_inode_int(args, &bno, count); + if (error) + return error; + + *dbp = xfs_dir2_da_to_db(args->geo, (xfs_dablk_t)bno); + + /* + * Update file's size if this is the data space and it grew. + */ + if (space == XFS_DIR2_DATA_SPACE) { + xfs_fsize_t size; /* directory file (data) size */ + + size = XFS_FSB_TO_B(mp, bno + count); + if (size > dp->i_disk_size) { + dp->i_disk_size = size; + xfs_trans_log_inode(args->trans, dp, XFS_ILOG_CORE); + } + } + return 0; +} + +/* + * See if the directory is a single-block form directory. + */ +int +xfs_dir2_isblock( + struct xfs_da_args *args, + bool *isblock) +{ + struct xfs_mount *mp = args->dp->i_mount; + xfs_fileoff_t eof; + int error; + + error = xfs_bmap_last_offset(args->dp, &eof, XFS_DATA_FORK); + if (error) + return error; + + *isblock = false; + if (XFS_FSB_TO_B(mp, eof) != args->geo->blksize) + return 0; + + *isblock = true; + if (XFS_IS_CORRUPT(mp, args->dp->i_disk_size != args->geo->blksize)) + return -EFSCORRUPTED; + return 0; +} + +/* + * See if the directory is a single-leaf form directory. + */ +int +xfs_dir2_isleaf( + struct xfs_da_args *args, + bool *isleaf) +{ + xfs_fileoff_t eof; + int error; + + error = xfs_bmap_last_offset(args->dp, &eof, XFS_DATA_FORK); + if (error) + return error; + + *isleaf = false; + if (eof != args->geo->leafblk + args->geo->fsbcount) + return 0; + + *isleaf = true; + return 0; +} + +/* + * Remove the given block from the directory. + * This routine is used for data and free blocks, leaf/node are done + * by xfs_da_shrink_inode. + */ +int +xfs_dir2_shrink_inode( + struct xfs_da_args *args, + xfs_dir2_db_t db, + struct xfs_buf *bp) +{ + xfs_fileoff_t bno; /* directory file offset */ + xfs_dablk_t da; /* directory file offset */ + int done; /* bunmap is finished */ + struct xfs_inode *dp; + int error; + struct xfs_mount *mp; + struct xfs_trans *tp; + + trace_xfs_dir2_shrink_inode(args, db); + + dp = args->dp; + mp = dp->i_mount; + tp = args->trans; + da = xfs_dir2_db_to_da(args->geo, db); + + /* Unmap the fsblock(s). */ + error = xfs_bunmapi(tp, dp, da, args->geo->fsbcount, 0, 0, &done); + if (error) { + /* + * ENOSPC actually can happen if we're in a removename with no + * space reservation, and the resulting block removal would + * cause a bmap btree split or conversion from extents to btree. + * This can only happen for un-fragmented directory blocks, + * since you need to be punching out the middle of an extent. + * In this case we need to leave the block in the file, and not + * binval it. So the block has to be in a consistent empty + * state and appropriately logged. We don't free up the buffer, + * the caller can tell it hasn't happened since it got an error + * back. + */ + return error; + } + ASSERT(done); + /* + * Invalidate the buffer from the transaction. + */ + xfs_trans_binval(tp, bp); + /* + * If it's not a data block, we're done. + */ + if (db >= xfs_dir2_byte_to_db(args->geo, XFS_DIR2_LEAF_OFFSET)) + return 0; + /* + * If the block isn't the last one in the directory, we're done. + */ + if (dp->i_disk_size > xfs_dir2_db_off_to_byte(args->geo, db + 1, 0)) + return 0; + bno = da; + if ((error = xfs_bmap_last_before(tp, dp, &bno, XFS_DATA_FORK))) { + /* + * This can't really happen unless there's kernel corruption. + */ + return error; + } + if (db == args->geo->datablk) + ASSERT(bno == 0); + else + ASSERT(bno > 0); + /* + * Set the size to the new last block. + */ + dp->i_disk_size = XFS_FSB_TO_B(mp, bno); + xfs_trans_log_inode(tp, dp, XFS_ILOG_CORE); + return 0; +} + +/* Returns true if the directory entry name is valid. */ +bool +xfs_dir2_namecheck( + const void *name, + size_t length) +{ + /* + * MAXNAMELEN includes the trailing null, but (name/length) leave it + * out, so use >= for the length check. + */ + if (length >= MAXNAMELEN) + return false; + + /* There shouldn't be any slashes or nulls here */ + return !memchr(name, '/', length) && !memchr(name, 0, length); +} + +xfs_dahash_t +xfs_dir2_hashname( + struct xfs_mount *mp, + const struct xfs_name *name) +{ + if (unlikely(xfs_has_asciici(mp))) + return xfs_ascii_ci_hashname(name); + return xfs_da_hashname(name->name, name->len); +} + +enum xfs_dacmp +xfs_dir2_compname( + struct xfs_da_args *args, + const unsigned char *name, + int len) +{ + if (unlikely(xfs_has_asciici(args->dp->i_mount))) + return xfs_ascii_ci_compname(args, name, len); + return xfs_da_compname(args, name, len); +} |