diff options
Diffstat (limited to 'kernel/fs/jfs/xattr.c')
| -rw-r--r-- | kernel/fs/jfs/xattr.c | 1106 |
1 files changed, 1106 insertions, 0 deletions
diff --git a/kernel/fs/jfs/xattr.c b/kernel/fs/jfs/xattr.c new file mode 100644 index 000000000..48b15a6e5 --- /dev/null +++ b/kernel/fs/jfs/xattr.c @@ -0,0 +1,1106 @@ +/* + * Copyright (C) International Business Machines Corp., 2000-2004 + * Copyright (C) Christoph Hellwig, 2002 + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * This program 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 this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/capability.h> +#include <linux/fs.h> +#include <linux/xattr.h> +#include <linux/posix_acl_xattr.h> +#include <linux/slab.h> +#include <linux/quotaops.h> +#include <linux/security.h> +#include "jfs_incore.h" +#include "jfs_superblock.h" +#include "jfs_dmap.h" +#include "jfs_debug.h" +#include "jfs_dinode.h" +#include "jfs_extent.h" +#include "jfs_metapage.h" +#include "jfs_xattr.h" +#include "jfs_acl.h" + +/* + * jfs_xattr.c: extended attribute service + * + * Overall design -- + * + * Format: + * + * Extended attribute lists (jfs_ea_list) consist of an overall size (32 bit + * value) and a variable (0 or more) number of extended attribute + * entries. Each extended attribute entry (jfs_ea) is a <name,value> double + * where <name> is constructed from a null-terminated ascii string + * (1 ... 255 bytes in the name) and <value> is arbitrary 8 bit data + * (1 ... 65535 bytes). The in-memory format is + * + * 0 1 2 4 4 + namelen + 1 + * +-------+--------+--------+----------------+-------------------+ + * | Flags | Name | Value | Name String \0 | Data . . . . | + * | | Length | Length | | | + * +-------+--------+--------+----------------+-------------------+ + * + * A jfs_ea_list then is structured as + * + * 0 4 4 + EA_SIZE(ea1) + * +------------+-------------------+--------------------+----- + * | Overall EA | First FEA Element | Second FEA Element | ..... + * | List Size | | | + * +------------+-------------------+--------------------+----- + * + * On-disk: + * + * FEALISTs are stored on disk using blocks allocated by dbAlloc() and + * written directly. An EA list may be in-lined in the inode if there is + * sufficient room available. + */ + +struct ea_buffer { + int flag; /* Indicates what storage xattr points to */ + int max_size; /* largest xattr that fits in current buffer */ + dxd_t new_ea; /* dxd to replace ea when modifying xattr */ + struct metapage *mp; /* metapage containing ea list */ + struct jfs_ea_list *xattr; /* buffer containing ea list */ +}; + +/* + * ea_buffer.flag values + */ +#define EA_INLINE 0x0001 +#define EA_EXTENT 0x0002 +#define EA_NEW 0x0004 +#define EA_MALLOC 0x0008 + + +static int is_known_namespace(const char *name) +{ + if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) && + strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) && + strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) && + strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN)) + return false; + + return true; +} + +/* + * These three routines are used to recognize on-disk extended attributes + * that are in a recognized namespace. If the attribute is not recognized, + * "os2." is prepended to the name + */ +static int is_os2_xattr(struct jfs_ea *ea) +{ + return !is_known_namespace(ea->name); +} + +static inline int name_size(struct jfs_ea *ea) +{ + if (is_os2_xattr(ea)) + return ea->namelen + XATTR_OS2_PREFIX_LEN; + else + return ea->namelen; +} + +static inline int copy_name(char *buffer, struct jfs_ea *ea) +{ + int len = ea->namelen; + + if (is_os2_xattr(ea)) { + memcpy(buffer, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN); + buffer += XATTR_OS2_PREFIX_LEN; + len += XATTR_OS2_PREFIX_LEN; + } + memcpy(buffer, ea->name, ea->namelen); + buffer[ea->namelen] = 0; + + return len; +} + +/* Forward references */ +static void ea_release(struct inode *inode, struct ea_buffer *ea_buf); + +/* + * NAME: ea_write_inline + * + * FUNCTION: Attempt to write an EA inline if area is available + * + * PRE CONDITIONS: + * Already verified that the specified EA is small enough to fit inline + * + * PARAMETERS: + * ip - Inode pointer + * ealist - EA list pointer + * size - size of ealist in bytes + * ea - dxd_t structure to be filled in with necessary EA information + * if we successfully copy the EA inline + * + * NOTES: + * Checks if the inode's inline area is available. If so, copies EA inline + * and sets <ea> fields appropriately. Otherwise, returns failure, EA will + * have to be put into an extent. + * + * RETURNS: 0 for successful copy to inline area; -1 if area not available + */ +static int ea_write_inline(struct inode *ip, struct jfs_ea_list *ealist, + int size, dxd_t * ea) +{ + struct jfs_inode_info *ji = JFS_IP(ip); + + /* + * Make sure we have an EA -- the NULL EA list is valid, but you + * can't copy it! + */ + if (ealist && size > sizeof (struct jfs_ea_list)) { + assert(size <= sizeof (ji->i_inline_ea)); + + /* + * See if the space is available or if it is already being + * used for an inline EA. + */ + if (!(ji->mode2 & INLINEEA) && !(ji->ea.flag & DXD_INLINE)) + return -EPERM; + + DXDsize(ea, size); + DXDlength(ea, 0); + DXDaddress(ea, 0); + memcpy(ji->i_inline_ea, ealist, size); + ea->flag = DXD_INLINE; + ji->mode2 &= ~INLINEEA; + } else { + ea->flag = 0; + DXDsize(ea, 0); + DXDlength(ea, 0); + DXDaddress(ea, 0); + + /* Free up INLINE area */ + if (ji->ea.flag & DXD_INLINE) + ji->mode2 |= INLINEEA; + } + + return 0; +} + +/* + * NAME: ea_write + * + * FUNCTION: Write an EA for an inode + * + * PRE CONDITIONS: EA has been verified + * + * PARAMETERS: + * ip - Inode pointer + * ealist - EA list pointer + * size - size of ealist in bytes + * ea - dxd_t structure to be filled in appropriately with where the + * EA was copied + * + * NOTES: Will write EA inline if able to, otherwise allocates blocks for an + * extent and synchronously writes it to those blocks. + * + * RETURNS: 0 for success; Anything else indicates failure + */ +static int ea_write(struct inode *ip, struct jfs_ea_list *ealist, int size, + dxd_t * ea) +{ + struct super_block *sb = ip->i_sb; + struct jfs_inode_info *ji = JFS_IP(ip); + struct jfs_sb_info *sbi = JFS_SBI(sb); + int nblocks; + s64 blkno; + int rc = 0, i; + char *cp; + s32 nbytes, nb; + s32 bytes_to_write; + struct metapage *mp; + + /* + * Quick check to see if this is an in-linable EA. Short EAs + * and empty EAs are all in-linable, provided the space exists. + */ + if (!ealist || size <= sizeof (ji->i_inline_ea)) { + if (!ea_write_inline(ip, ealist, size, ea)) + return 0; + } + + /* figure out how many blocks we need */ + nblocks = (size + (sb->s_blocksize - 1)) >> sb->s_blocksize_bits; + + /* Allocate new blocks to quota. */ + rc = dquot_alloc_block(ip, nblocks); + if (rc) + return rc; + + rc = dbAlloc(ip, INOHINT(ip), nblocks, &blkno); + if (rc) { + /*Rollback quota allocation. */ + dquot_free_block(ip, nblocks); + return rc; + } + + /* + * Now have nblocks worth of storage to stuff into the FEALIST. + * loop over the FEALIST copying data into the buffer one page at + * a time. + */ + cp = (char *) ealist; + nbytes = size; + for (i = 0; i < nblocks; i += sbi->nbperpage) { + /* + * Determine how many bytes for this request, and round up to + * the nearest aggregate block size + */ + nb = min(PSIZE, nbytes); + bytes_to_write = + ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits)) + << sb->s_blocksize_bits; + + if (!(mp = get_metapage(ip, blkno + i, bytes_to_write, 1))) { + rc = -EIO; + goto failed; + } + + memcpy(mp->data, cp, nb); + + /* + * We really need a way to propagate errors for + * forced writes like this one. --hch + * + * (__write_metapage => release_metapage => flush_metapage) + */ +#ifdef _JFS_FIXME + if ((rc = flush_metapage(mp))) { + /* + * the write failed -- this means that the buffer + * is still assigned and the blocks are not being + * used. this seems like the best error recovery + * we can get ... + */ + goto failed; + } +#else + flush_metapage(mp); +#endif + + cp += PSIZE; + nbytes -= nb; + } + + ea->flag = DXD_EXTENT; + DXDsize(ea, le32_to_cpu(ealist->size)); + DXDlength(ea, nblocks); + DXDaddress(ea, blkno); + + /* Free up INLINE area */ + if (ji->ea.flag & DXD_INLINE) + ji->mode2 |= INLINEEA; + + return 0; + + failed: + /* Rollback quota allocation. */ + dquot_free_block(ip, nblocks); + + dbFree(ip, blkno, nblocks); + return rc; +} + +/* + * NAME: ea_read_inline + * + * FUNCTION: Read an inlined EA into user's buffer + * + * PARAMETERS: + * ip - Inode pointer + * ealist - Pointer to buffer to fill in with EA + * + * RETURNS: 0 + */ +static int ea_read_inline(struct inode *ip, struct jfs_ea_list *ealist) +{ + struct jfs_inode_info *ji = JFS_IP(ip); + int ea_size = sizeDXD(&ji->ea); + + if (ea_size == 0) { + ealist->size = 0; + return 0; + } + + /* Sanity Check */ + if ((sizeDXD(&ji->ea) > sizeof (ji->i_inline_ea))) + return -EIO; + if (le32_to_cpu(((struct jfs_ea_list *) &ji->i_inline_ea)->size) + != ea_size) + return -EIO; + + memcpy(ealist, ji->i_inline_ea, ea_size); + return 0; +} + +/* + * NAME: ea_read + * + * FUNCTION: copy EA data into user's buffer + * + * PARAMETERS: + * ip - Inode pointer + * ealist - Pointer to buffer to fill in with EA + * + * NOTES: If EA is inline calls ea_read_inline() to copy EA. + * + * RETURNS: 0 for success; other indicates failure + */ +static int ea_read(struct inode *ip, struct jfs_ea_list *ealist) +{ + struct super_block *sb = ip->i_sb; + struct jfs_inode_info *ji = JFS_IP(ip); + struct jfs_sb_info *sbi = JFS_SBI(sb); + int nblocks; + s64 blkno; + char *cp = (char *) ealist; + int i; + int nbytes, nb; + s32 bytes_to_read; + struct metapage *mp; + + /* quick check for in-line EA */ + if (ji->ea.flag & DXD_INLINE) + return ea_read_inline(ip, ealist); + + nbytes = sizeDXD(&ji->ea); + if (!nbytes) { + jfs_error(sb, "nbytes is 0\n"); + return -EIO; + } + + /* + * Figure out how many blocks were allocated when this EA list was + * originally written to disk. + */ + nblocks = lengthDXD(&ji->ea) << sbi->l2nbperpage; + blkno = addressDXD(&ji->ea) << sbi->l2nbperpage; + + /* + * I have found the disk blocks which were originally used to store + * the FEALIST. now i loop over each contiguous block copying the + * data into the buffer. + */ + for (i = 0; i < nblocks; i += sbi->nbperpage) { + /* + * Determine how many bytes for this request, and round up to + * the nearest aggregate block size + */ + nb = min(PSIZE, nbytes); + bytes_to_read = + ((((nb + sb->s_blocksize - 1)) >> sb->s_blocksize_bits)) + << sb->s_blocksize_bits; + + if (!(mp = read_metapage(ip, blkno + i, bytes_to_read, 1))) + return -EIO; + + memcpy(cp, mp->data, nb); + release_metapage(mp); + + cp += PSIZE; + nbytes -= nb; + } + + return 0; +} + +/* + * NAME: ea_get + * + * FUNCTION: Returns buffer containing existing extended attributes. + * The size of the buffer will be the larger of the existing + * attributes size, or min_size. + * + * The buffer, which may be inlined in the inode or in the + * page cache must be release by calling ea_release or ea_put + * + * PARAMETERS: + * inode - Inode pointer + * ea_buf - Structure to be populated with ealist and its metadata + * min_size- minimum size of buffer to be returned + * + * RETURNS: 0 for success; Other indicates failure + */ +static int ea_get(struct inode *inode, struct ea_buffer *ea_buf, int min_size) +{ + struct jfs_inode_info *ji = JFS_IP(inode); + struct super_block *sb = inode->i_sb; + int size; + int ea_size = sizeDXD(&ji->ea); + int blocks_needed, current_blocks; + s64 blkno; + int rc; + int quota_allocation = 0; + + /* When fsck.jfs clears a bad ea, it doesn't clear the size */ + if (ji->ea.flag == 0) + ea_size = 0; + + if (ea_size == 0) { + if (min_size == 0) { + ea_buf->flag = 0; + ea_buf->max_size = 0; + ea_buf->xattr = NULL; + return 0; + } + if ((min_size <= sizeof (ji->i_inline_ea)) && + (ji->mode2 & INLINEEA)) { + ea_buf->flag = EA_INLINE | EA_NEW; + ea_buf->max_size = sizeof (ji->i_inline_ea); + ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea; + DXDlength(&ea_buf->new_ea, 0); + DXDaddress(&ea_buf->new_ea, 0); + ea_buf->new_ea.flag = DXD_INLINE; + DXDsize(&ea_buf->new_ea, min_size); + return 0; + } + current_blocks = 0; + } else if (ji->ea.flag & DXD_INLINE) { + if (min_size <= sizeof (ji->i_inline_ea)) { + ea_buf->flag = EA_INLINE; + ea_buf->max_size = sizeof (ji->i_inline_ea); + ea_buf->xattr = (struct jfs_ea_list *) ji->i_inline_ea; + goto size_check; + } + current_blocks = 0; + } else { + if (!(ji->ea.flag & DXD_EXTENT)) { + jfs_error(sb, "invalid ea.flag\n"); + return -EIO; + } + current_blocks = (ea_size + sb->s_blocksize - 1) >> + sb->s_blocksize_bits; + } + size = max(min_size, ea_size); + + if (size > PSIZE) { + /* + * To keep the rest of the code simple. Allocate a + * contiguous buffer to work with + */ + ea_buf->xattr = kmalloc(size, GFP_KERNEL); + if (ea_buf->xattr == NULL) + return -ENOMEM; + + ea_buf->flag = EA_MALLOC; + ea_buf->max_size = (size + sb->s_blocksize - 1) & + ~(sb->s_blocksize - 1); + + if (ea_size == 0) + return 0; + + if ((rc = ea_read(inode, ea_buf->xattr))) { + kfree(ea_buf->xattr); + ea_buf->xattr = NULL; + return rc; + } + goto size_check; + } + blocks_needed = (min_size + sb->s_blocksize - 1) >> + sb->s_blocksize_bits; + + if (blocks_needed > current_blocks) { + /* Allocate new blocks to quota. */ + rc = dquot_alloc_block(inode, blocks_needed); + if (rc) + return -EDQUOT; + + quota_allocation = blocks_needed; + + rc = dbAlloc(inode, INOHINT(inode), (s64) blocks_needed, + &blkno); + if (rc) + goto clean_up; + + DXDlength(&ea_buf->new_ea, blocks_needed); + DXDaddress(&ea_buf->new_ea, blkno); + ea_buf->new_ea.flag = DXD_EXTENT; + DXDsize(&ea_buf->new_ea, min_size); + + ea_buf->flag = EA_EXTENT | EA_NEW; + + ea_buf->mp = get_metapage(inode, blkno, + blocks_needed << sb->s_blocksize_bits, + 1); + if (ea_buf->mp == NULL) { + dbFree(inode, blkno, (s64) blocks_needed); + rc = -EIO; + goto clean_up; + } + ea_buf->xattr = ea_buf->mp->data; + ea_buf->max_size = (min_size + sb->s_blocksize - 1) & + ~(sb->s_blocksize - 1); + if (ea_size == 0) + return 0; + if ((rc = ea_read(inode, ea_buf->xattr))) { + discard_metapage(ea_buf->mp); + dbFree(inode, blkno, (s64) blocks_needed); + goto clean_up; + } + goto size_check; + } + ea_buf->flag = EA_EXTENT; + ea_buf->mp = read_metapage(inode, addressDXD(&ji->ea), + lengthDXD(&ji->ea) << sb->s_blocksize_bits, + 1); + if (ea_buf->mp == NULL) { + rc = -EIO; + goto clean_up; + } + ea_buf->xattr = ea_buf->mp->data; + ea_buf->max_size = (ea_size + sb->s_blocksize - 1) & + ~(sb->s_blocksize - 1); + + size_check: + if (EALIST_SIZE(ea_buf->xattr) != ea_size) { + printk(KERN_ERR "ea_get: invalid extended attribute\n"); + print_hex_dump(KERN_ERR, "", DUMP_PREFIX_ADDRESS, 16, 1, + ea_buf->xattr, ea_size, 1); + ea_release(inode, ea_buf); + rc = -EIO; + goto clean_up; + } + + return ea_size; + + clean_up: + /* Rollback quota allocation */ + if (quota_allocation) + dquot_free_block(inode, quota_allocation); + + return (rc); +} + +static void ea_release(struct inode *inode, struct ea_buffer *ea_buf) +{ + if (ea_buf->flag & EA_MALLOC) + kfree(ea_buf->xattr); + else if (ea_buf->flag & EA_EXTENT) { + assert(ea_buf->mp); + release_metapage(ea_buf->mp); + + if (ea_buf->flag & EA_NEW) + dbFree(inode, addressDXD(&ea_buf->new_ea), + lengthDXD(&ea_buf->new_ea)); + } +} + +static int ea_put(tid_t tid, struct inode *inode, struct ea_buffer *ea_buf, + int new_size) +{ + struct jfs_inode_info *ji = JFS_IP(inode); + unsigned long old_blocks, new_blocks; + int rc = 0; + + if (new_size == 0) { + ea_release(inode, ea_buf); + ea_buf = NULL; + } else if (ea_buf->flag & EA_INLINE) { + assert(new_size <= sizeof (ji->i_inline_ea)); + ji->mode2 &= ~INLINEEA; + ea_buf->new_ea.flag = DXD_INLINE; + DXDsize(&ea_buf->new_ea, new_size); + DXDaddress(&ea_buf->new_ea, 0); + DXDlength(&ea_buf->new_ea, 0); + } else if (ea_buf->flag & EA_MALLOC) { + rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea); + kfree(ea_buf->xattr); + } else if (ea_buf->flag & EA_NEW) { + /* We have already allocated a new dxd */ + flush_metapage(ea_buf->mp); + } else { + /* ->xattr must point to original ea's metapage */ + rc = ea_write(inode, ea_buf->xattr, new_size, &ea_buf->new_ea); + discard_metapage(ea_buf->mp); + } + if (rc) + return rc; + + old_blocks = new_blocks = 0; + + if (ji->ea.flag & DXD_EXTENT) { + invalidate_dxd_metapages(inode, ji->ea); + old_blocks = lengthDXD(&ji->ea); + } + + if (ea_buf) { + txEA(tid, inode, &ji->ea, &ea_buf->new_ea); + if (ea_buf->new_ea.flag & DXD_EXTENT) { + new_blocks = lengthDXD(&ea_buf->new_ea); + if (ji->ea.flag & DXD_INLINE) + ji->mode2 |= INLINEEA; + } + ji->ea = ea_buf->new_ea; + } else { + txEA(tid, inode, &ji->ea, NULL); + if (ji->ea.flag & DXD_INLINE) + ji->mode2 |= INLINEEA; + ji->ea.flag = 0; + ji->ea.size = 0; + } + + /* If old blocks exist, they must be removed from quota allocation. */ + if (old_blocks) + dquot_free_block(inode, old_blocks); + + inode->i_ctime = CURRENT_TIME; + + return 0; +} + +/* + * Most of the permission checking is done by xattr_permission in the vfs. + * We also need to verify that this is a namespace that we recognize. + */ +static int can_set_xattr(struct inode *inode, const char *name, + const void *value, size_t value_len) +{ + if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) { + /* + * This makes sure that we aren't trying to set an + * attribute in a different namespace by prefixing it + * with "os2." + */ + if (is_known_namespace(name + XATTR_OS2_PREFIX_LEN)) + return -EOPNOTSUPP; + return 0; + } + + /* + * Don't allow setting an attribute in an unknown namespace. + */ + if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) && + strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) && + strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN)) + return -EOPNOTSUPP; + + return 0; +} + +int __jfs_setxattr(tid_t tid, struct inode *inode, const char *name, + const void *value, size_t value_len, int flags) +{ + struct jfs_ea_list *ealist; + struct jfs_ea *ea, *old_ea = NULL, *next_ea = NULL; + struct ea_buffer ea_buf; + int old_ea_size = 0; + int xattr_size; + int new_size; + int namelen = strlen(name); + char *os2name = NULL; + int found = 0; + int rc; + int length; + + if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) { + os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1, + GFP_KERNEL); + if (!os2name) + return -ENOMEM; + strcpy(os2name, name + XATTR_OS2_PREFIX_LEN); + name = os2name; + namelen -= XATTR_OS2_PREFIX_LEN; + } + + down_write(&JFS_IP(inode)->xattr_sem); + + xattr_size = ea_get(inode, &ea_buf, 0); + if (xattr_size < 0) { + rc = xattr_size; + goto out; + } + + again: + ealist = (struct jfs_ea_list *) ea_buf.xattr; + new_size = sizeof (struct jfs_ea_list); + + if (xattr_size) { + for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); + ea = NEXT_EA(ea)) { + if ((namelen == ea->namelen) && + (memcmp(name, ea->name, namelen) == 0)) { + found = 1; + if (flags & XATTR_CREATE) { + rc = -EEXIST; + goto release; + } + old_ea = ea; + old_ea_size = EA_SIZE(ea); + next_ea = NEXT_EA(ea); + } else + new_size += EA_SIZE(ea); + } + } + + if (!found) { + if (flags & XATTR_REPLACE) { + rc = -ENODATA; + goto release; + } + if (value == NULL) { + rc = 0; + goto release; + } + } + if (value) + new_size += sizeof (struct jfs_ea) + namelen + 1 + value_len; + + if (new_size > ea_buf.max_size) { + /* + * We need to allocate more space for merged ea list. + * We should only have loop to again: once. + */ + ea_release(inode, &ea_buf); + xattr_size = ea_get(inode, &ea_buf, new_size); + if (xattr_size < 0) { + rc = xattr_size; + goto out; + } + goto again; + } + + /* Remove old ea of the same name */ + if (found) { + /* number of bytes following target EA */ + length = (char *) END_EALIST(ealist) - (char *) next_ea; + if (length > 0) + memmove(old_ea, next_ea, length); + xattr_size -= old_ea_size; + } + + /* Add new entry to the end */ + if (value) { + if (xattr_size == 0) + /* Completely new ea list */ + xattr_size = sizeof (struct jfs_ea_list); + + /* + * The size of EA value is limitted by on-disk format up to + * __le16, there would be an overflow if the size is equal + * to XATTR_SIZE_MAX (65536). In order to avoid this issue, + * we can pre-checkup the value size against USHRT_MAX, and + * return -E2BIG in this case, which is consistent with the + * VFS setxattr interface. + */ + if (value_len >= USHRT_MAX) { + rc = -E2BIG; + goto release; + } + + ea = (struct jfs_ea *) ((char *) ealist + xattr_size); + ea->flag = 0; + ea->namelen = namelen; + ea->valuelen = (cpu_to_le16(value_len)); + memcpy(ea->name, name, namelen); + ea->name[namelen] = 0; + if (value_len) + memcpy(&ea->name[namelen + 1], value, value_len); + xattr_size += EA_SIZE(ea); + } + + /* DEBUG - If we did this right, these number match */ + if (xattr_size != new_size) { + printk(KERN_ERR + "__jfs_setxattr: xattr_size = %d, new_size = %d\n", + xattr_size, new_size); + + rc = -EINVAL; + goto release; + } + + /* + * If we're left with an empty list, there's no ea + */ + if (new_size == sizeof (struct jfs_ea_list)) + new_size = 0; + + ealist->size = cpu_to_le32(new_size); + + rc = ea_put(tid, inode, &ea_buf, new_size); + + goto out; + release: + ea_release(inode, &ea_buf); + out: + up_write(&JFS_IP(inode)->xattr_sem); + + kfree(os2name); + + return rc; +} + +int jfs_setxattr(struct dentry *dentry, const char *name, const void *value, + size_t value_len, int flags) +{ + struct inode *inode = d_inode(dentry); + struct jfs_inode_info *ji = JFS_IP(inode); + int rc; + tid_t tid; + + /* + * If this is a request for a synthetic attribute in the system.* + * namespace use the generic infrastructure to resolve a handler + * for it via sb->s_xattr. + */ + if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) + return generic_setxattr(dentry, name, value, value_len, flags); + + if ((rc = can_set_xattr(inode, name, value, value_len))) + return rc; + + if (value == NULL) { /* empty EA, do not remove */ + value = ""; + value_len = 0; + } + + tid = txBegin(inode->i_sb, 0); + mutex_lock(&ji->commit_mutex); + rc = __jfs_setxattr(tid, d_inode(dentry), name, value, value_len, + flags); + if (!rc) + rc = txCommit(tid, 1, &inode, 0); + txEnd(tid); + mutex_unlock(&ji->commit_mutex); + + return rc; +} + +ssize_t __jfs_getxattr(struct inode *inode, const char *name, void *data, + size_t buf_size) +{ + struct jfs_ea_list *ealist; + struct jfs_ea *ea; + struct ea_buffer ea_buf; + int xattr_size; + ssize_t size; + int namelen = strlen(name); + char *value; + + down_read(&JFS_IP(inode)->xattr_sem); + + xattr_size = ea_get(inode, &ea_buf, 0); + + if (xattr_size < 0) { + size = xattr_size; + goto out; + } + + if (xattr_size == 0) + goto not_found; + + ealist = (struct jfs_ea_list *) ea_buf.xattr; + + /* Find the named attribute */ + for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) + if ((namelen == ea->namelen) && + memcmp(name, ea->name, namelen) == 0) { + /* Found it */ + size = le16_to_cpu(ea->valuelen); + if (!data) + goto release; + else if (size > buf_size) { + size = -ERANGE; + goto release; + } + value = ((char *) &ea->name) + ea->namelen + 1; + memcpy(data, value, size); + goto release; + } + not_found: + size = -ENODATA; + release: + ea_release(inode, &ea_buf); + out: + up_read(&JFS_IP(inode)->xattr_sem); + + return size; +} + +ssize_t jfs_getxattr(struct dentry *dentry, const char *name, void *data, + size_t buf_size) +{ + int err; + + /* + * If this is a request for a synthetic attribute in the system.* + * namespace use the generic infrastructure to resolve a handler + * for it via sb->s_xattr. + */ + if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) + return generic_getxattr(dentry, name, data, buf_size); + + if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) { + /* + * skip past "os2." prefix + */ + name += XATTR_OS2_PREFIX_LEN; + /* + * Don't allow retrieving properly prefixed attributes + * by prepending them with "os2." + */ + if (is_known_namespace(name)) + return -EOPNOTSUPP; + } + + err = __jfs_getxattr(d_inode(dentry), name, data, buf_size); + + return err; +} + +/* + * No special permissions are needed to list attributes except for trusted.* + */ +static inline int can_list(struct jfs_ea *ea) +{ + return (strncmp(ea->name, XATTR_TRUSTED_PREFIX, + XATTR_TRUSTED_PREFIX_LEN) || + capable(CAP_SYS_ADMIN)); +} + +ssize_t jfs_listxattr(struct dentry * dentry, char *data, size_t buf_size) +{ + struct inode *inode = d_inode(dentry); + char *buffer; + ssize_t size = 0; + int xattr_size; + struct jfs_ea_list *ealist; + struct jfs_ea *ea; + struct ea_buffer ea_buf; + + down_read(&JFS_IP(inode)->xattr_sem); + + xattr_size = ea_get(inode, &ea_buf, 0); + if (xattr_size < 0) { + size = xattr_size; + goto out; + } + + if (xattr_size == 0) + goto release; + + ealist = (struct jfs_ea_list *) ea_buf.xattr; + + /* compute required size of list */ + for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) { + if (can_list(ea)) + size += name_size(ea) + 1; + } + + if (!data) + goto release; + + if (size > buf_size) { + size = -ERANGE; + goto release; + } + + /* Copy attribute names to buffer */ + buffer = data; + for (ea = FIRST_EA(ealist); ea < END_EALIST(ealist); ea = NEXT_EA(ea)) { + if (can_list(ea)) { + int namelen = copy_name(buffer, ea); + buffer += namelen + 1; + } + } + + release: + ea_release(inode, &ea_buf); + out: + up_read(&JFS_IP(inode)->xattr_sem); + return size; +} + +int jfs_removexattr(struct dentry *dentry, const char *name) +{ + struct inode *inode = d_inode(dentry); + struct jfs_inode_info *ji = JFS_IP(inode); + int rc; + tid_t tid; + + /* + * If this is a request for a synthetic attribute in the system.* + * namespace use the generic infrastructure to resolve a handler + * for it via sb->s_xattr. + */ + if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN)) + return generic_removexattr(dentry, name); + + if ((rc = can_set_xattr(inode, name, NULL, 0))) + return rc; + + tid = txBegin(inode->i_sb, 0); + mutex_lock(&ji->commit_mutex); + rc = __jfs_setxattr(tid, d_inode(dentry), name, NULL, 0, XATTR_REPLACE); + if (!rc) + rc = txCommit(tid, 1, &inode, 0); + txEnd(tid); + mutex_unlock(&ji->commit_mutex); + + return rc; +} + +/* + * List of handlers for synthetic system.* attributes. All real ondisk + * attributes are handled directly. + */ +const struct xattr_handler *jfs_xattr_handlers[] = { +#ifdef CONFIG_JFS_POSIX_ACL + &posix_acl_access_xattr_handler, + &posix_acl_default_xattr_handler, +#endif + NULL, +}; + + +#ifdef CONFIG_JFS_SECURITY +static int jfs_initxattrs(struct inode *inode, const struct xattr *xattr_array, + void *fs_info) +{ + const struct xattr *xattr; + tid_t *tid = fs_info; + char *name; + int err = 0; + + for (xattr = xattr_array; xattr->name != NULL; xattr++) { + name = kmalloc(XATTR_SECURITY_PREFIX_LEN + + strlen(xattr->name) + 1, GFP_NOFS); + if (!name) { + err = -ENOMEM; + break; + } + strcpy(name, XATTR_SECURITY_PREFIX); + strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name); + + err = __jfs_setxattr(*tid, inode, name, + xattr->value, xattr->value_len, 0); + kfree(name); + if (err < 0) + break; + } + return err; +} + +int jfs_init_security(tid_t tid, struct inode *inode, struct inode *dir, + const struct qstr *qstr) +{ + return security_inode_init_security(inode, dir, qstr, + &jfs_initxattrs, &tid); +} +#endif |