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authorSteven Whitehouse <swhiteho@redhat.com>2008-10-14 14:43:29 +0100
committerSteven Whitehouse <swhiteho@redhat.com>2009-01-05 07:38:46 +0000
commite9079cce201784632aed4b1a3121ee38c1ced0b6 (patch)
tree6d99fc45afb3889e5835d713948226d7548d6750
parentfe0bdec68b77020281dc814805edfe594ae89e0f (diff)
GFS2: Support for FIEMAP ioctl
This patch implements the FIEMAP ioctl for GFS2. We can use the generic code (aside from a lock order issue, solved as per Ted Tso's suggestion) for which I've introduced a new variant of the generic function. We also have one exception to deal with, namely stuffed files, so we do that "by hand", setting all the required flags. This has been tested with a modified (I could only find an old version) of Eric's test program, and appears to work correctly. This patch does not currently support FIEMAP of xattrs, but the plan is to add that feature at some future point. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Theodore Tso <tytso@mit.edu> Cc: Eric Sandeen <sandeen@redhat.com>
-rw-r--r--fs/gfs2/ops_inode.c46
-rw-r--r--fs/ioctl.c44
-rw-r--r--include/linux/fs.h3
3 files changed, 83 insertions, 10 deletions
diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c
index d232991b904..1e24b65e1d2 100644
--- a/fs/gfs2/ops_inode.c
+++ b/fs/gfs2/ops_inode.c
@@ -19,6 +19,7 @@
#include <linux/gfs2_ondisk.h>
#include <linux/crc32.h>
#include <linux/lm_interface.h>
+#include <linux/fiemap.h>
#include <asm/uaccess.h>
#include "gfs2.h"
@@ -1212,6 +1213,48 @@ static int gfs2_removexattr(struct dentry *dentry, const char *name)
return gfs2_ea_remove(GFS2_I(dentry->d_inode), &er);
}
+static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
+ u64 start, u64 len)
+{
+ struct gfs2_inode *ip = GFS2_I(inode);
+ struct gfs2_holder gh;
+ int ret;
+
+ ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
+ if (ret)
+ return ret;
+
+ mutex_lock(&inode->i_mutex);
+
+ ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
+ if (ret)
+ goto out;
+
+ if (gfs2_is_stuffed(ip)) {
+ u64 phys = ip->i_no_addr << inode->i_blkbits;
+ u64 size = i_size_read(inode);
+ u32 flags = FIEMAP_EXTENT_LAST|FIEMAP_EXTENT_NOT_ALIGNED|
+ FIEMAP_EXTENT_DATA_INLINE;
+ phys += sizeof(struct gfs2_dinode);
+ phys += start;
+ if (start + len > size)
+ len = size - start;
+ if (start < size)
+ ret = fiemap_fill_next_extent(fieinfo, start, phys,
+ len, flags);
+ if (ret == 1)
+ ret = 0;
+ } else {
+ ret = __generic_block_fiemap(inode, fieinfo, start, len,
+ gfs2_block_map);
+ }
+
+ gfs2_glock_dq_uninit(&gh);
+out:
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+}
+
const struct inode_operations gfs2_file_iops = {
.permission = gfs2_permission,
.setattr = gfs2_setattr,
@@ -1220,6 +1263,7 @@ const struct inode_operations gfs2_file_iops = {
.getxattr = gfs2_getxattr,
.listxattr = gfs2_listxattr,
.removexattr = gfs2_removexattr,
+ .fiemap = gfs2_fiemap,
};
const struct inode_operations gfs2_dir_iops = {
@@ -1239,6 +1283,7 @@ const struct inode_operations gfs2_dir_iops = {
.getxattr = gfs2_getxattr,
.listxattr = gfs2_listxattr,
.removexattr = gfs2_removexattr,
+ .fiemap = gfs2_fiemap,
};
const struct inode_operations gfs2_symlink_iops = {
@@ -1251,5 +1296,6 @@ const struct inode_operations gfs2_symlink_iops = {
.getxattr = gfs2_getxattr,
.listxattr = gfs2_listxattr,
.removexattr = gfs2_removexattr,
+ .fiemap = gfs2_fiemap,
};
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 43e8b2c0664..cc3f1aa1cf7 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -231,7 +231,8 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
#define blk_to_logical(inode, blk) (blk << (inode)->i_blkbits)
#define logical_to_blk(inode, offset) (offset >> (inode)->i_blkbits);
-/*
+/**
+ * __generic_block_fiemap - FIEMAP for block based inodes (no locking)
* @inode - the inode to map
* @arg - the pointer to userspace where we copy everything to
* @get_block - the fs's get_block function
@@ -242,11 +243,15 @@ static int ioctl_fiemap(struct file *filp, unsigned long arg)
*
* If it is possible to have data blocks beyond a hole past @inode->i_size, then
* please do not use this function, it will stop at the first unmapped block
- * beyond i_size
+ * beyond i_size.
+ *
+ * If you use this function directly, you need to do your own locking. Use
+ * generic_block_fiemap if you want the locking done for you.
*/
-int generic_block_fiemap(struct inode *inode,
- struct fiemap_extent_info *fieinfo, u64 start,
- u64 len, get_block_t *get_block)
+
+int __generic_block_fiemap(struct inode *inode,
+ struct fiemap_extent_info *fieinfo, u64 start,
+ u64 len, get_block_t *get_block)
{
struct buffer_head tmp;
unsigned int start_blk;
@@ -260,9 +265,6 @@ int generic_block_fiemap(struct inode *inode,
start_blk = logical_to_blk(inode, start);
- /* guard against change */
- mutex_lock(&inode->i_mutex);
-
length = (long long)min_t(u64, len, i_size_read(inode));
map_len = length;
@@ -334,14 +336,36 @@ int generic_block_fiemap(struct inode *inode,
cond_resched();
} while (1);
- mutex_unlock(&inode->i_mutex);
-
/* if ret is 1 then we just hit the end of the extent array */
if (ret == 1)
ret = 0;
return ret;
}
+EXPORT_SYMBOL(__generic_block_fiemap);
+
+/**
+ * generic_block_fiemap - FIEMAP for block based inodes
+ * @inode: The inode to map
+ * @fieinfo: The mapping information
+ * @start: The initial block to map
+ * @len: The length of the extect to attempt to map
+ * @get_block: The block mapping function for the fs
+ *
+ * Calls __generic_block_fiemap to map the inode, after taking
+ * the inode's mutex lock.
+ */
+
+int generic_block_fiemap(struct inode *inode,
+ struct fiemap_extent_info *fieinfo, u64 start,
+ u64 len, get_block_t *get_block)
+{
+ int ret;
+ mutex_lock(&inode->i_mutex);
+ ret = __generic_block_fiemap(inode, fieinfo, start, len, get_block);
+ mutex_unlock(&inode->i_mutex);
+ return ret;
+}
EXPORT_SYMBOL(generic_block_fiemap);
#endif /* CONFIG_BLOCK */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f2a3010140e..e34bc6925fd 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2059,6 +2059,9 @@ extern int vfs_fstat(unsigned int, struct kstat *);
extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
unsigned long arg);
+extern int __generic_block_fiemap(struct inode *inode,
+ struct fiemap_extent_info *fieinfo, u64 start,
+ u64 len, get_block_t *get_block);
extern int generic_block_fiemap(struct inode *inode,
struct fiemap_extent_info *fieinfo, u64 start,
u64 len, get_block_t *get_block);